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Does Abatacept and Prednisolone interact?

•Drug A: Abatacept •Drug B: Prednisolone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Prednisolone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Prednisolone is indicated to treat endocrine, rheumatic, and hematologic disorders; collagen, dermatologic, ophthalmic, respiratory, and gastrointestinal diseases; allergic and edematous states; and other conditions like tuberculous meningitis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisolone has a short duration of action as the half life is 2.1-3.5 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral prednisolone reaches a C max of 113-1343ng/mL with a T max of 1.0-2.6 hours. Oral prednisolone is approximately 70% bioavailable. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A 0.15mg/kg dose of prednisolone has a volume of distribution of 29.3L, while a 0.30mg/kg dose has a volume of distribution of 44.2L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Prednisolone's protein binding is highly variable, ranging from 65-91% in healthy patients. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prednisolone can be reversibly metabolized to prednisone which is then metabolized to 17α,21-dihydroxy-pregnan-1,4,6-trien-3,11,30-trione (M-XVII), 20α-dihydro-prednisone (M-V), 6βhydroxy-prednisone (M-XII), 6α-hydroxy-prednisone (M-XIII), or 20β-dihydro-prednisone (M-IV). 20β-dihydro-prednisone is metabolized to 17α,20ξ,21-trihydroxy-5ξ-pregn-1-en-3,11-dione(M-XVIII). Prednisolone is metabolized to Δ6-prednisolone (M-XI), 20α-dihydro-prednisolone (M-III), 20β-dihydro-prednisolone (M-II), 6αhydroxy-prednisolone (M-VII), or 6βhydroxy-prednisolone(M-VI). 6αhydroxy-prednisolone is metabolized to 6α,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-X). 6βhydroxy-prednisolone is metabolized to 6β,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-VIII), 6β,11β,17α,20α,21-pentahydroxypregnan-1,4-diene-3-one (M-IX), and 6β,11β,17α,21-tetrahydroxy-5ξ-pregn-1-en-3,20-dione (M-XIV). MVIII is metabolized to 6β,11β,17α,20β,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XV) and then to MXIV, while MIX is metabolized to 6β,11β,17α,20α,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XVI) and then to MXIV. These metabolites and their glucuronide conjugates are excreted predominantly in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prednisolone is over 98% eliminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Prednisolone has a plasma half life of 2.1-3.5 hours. This half life is shorter in children and longer in those with liver disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): A 0.15mg/kg dose of prednisolone has a clearance of 0.09L/kg/h, while a 0.30mg/kg dose has a clearance of 0.12L/kg/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The intraperitoneal LD 50 in rats is 2g/kg and 65mg/kg in mice. The subcutaneous LD 50 in rats is 147mg/kg and >3500mg/kg in mice. The oral LD 50 in mice is 1680mg/kg. In humans, the oral TDLO in men is 9mg/kg/2W and in women is 14mg/kg/13D. Patients experiencing an overdose of prednisolone may present with gastrointestinal disturbances, insomnia, and restlessness. Overdose of oral prednisolone may be treated by gastric lavage or inducing vomiting if the overdose was recent, as well as supportive and symptomatic therapy. Chronic overdosage may be treated by dose reduction or treating patients on alternate days. An overdose by the ophthalmic route is not expected to cause problems. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Millipred Dp 6 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): delta-dehydrocortisol delta-dehydrohydrocortisone delta-hydrocortisone delta(1)-Dehydrocortisol delta(1)-Hydrocortisone Hydroretrocortine Metacortandralone PRDL Prednisolona Prednisolone Prednisolonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prednisolone is a glucocorticoid used to treat adrenocortical insufficiency, inflammatory conditions, and some cancers.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Prednisolone interact? Information: •Drug A: Abatacept •Drug B: Prednisolone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Prednisolone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Prednisolone is indicated to treat endocrine, rheumatic, and hematologic disorders; collagen, dermatologic, ophthalmic, respiratory, and gastrointestinal diseases; allergic and edematous states; and other conditions like tuberculous meningitis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisolone has a short duration of action as the half life is 2.1-3.5 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral prednisolone reaches a C max of 113-1343ng/mL with a T max of 1.0-2.6 hours. Oral prednisolone is approximately 70% bioavailable. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A 0.15mg/kg dose of prednisolone has a volume of distribution of 29.3L, while a 0.30mg/kg dose has a volume of distribution of 44.2L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Prednisolone's protein binding is highly variable, ranging from 65-91% in healthy patients. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prednisolone can be reversibly metabolized to prednisone which is then metabolized to 17α,21-dihydroxy-pregnan-1,4,6-trien-3,11,30-trione (M-XVII), 20α-dihydro-prednisone (M-V), 6βhydroxy-prednisone (M-XII), 6α-hydroxy-prednisone (M-XIII), or 20β-dihydro-prednisone (M-IV). 20β-dihydro-prednisone is metabolized to 17α,20ξ,21-trihydroxy-5ξ-pregn-1-en-3,11-dione(M-XVIII). Prednisolone is metabolized to Δ6-prednisolone (M-XI), 20α-dihydro-prednisolone (M-III), 20β-dihydro-prednisolone (M-II), 6αhydroxy-prednisolone (M-VII), or 6βhydroxy-prednisolone(M-VI). 6αhydroxy-prednisolone is metabolized to 6α,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-X). 6βhydroxy-prednisolone is metabolized to 6β,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-VIII), 6β,11β,17α,20α,21-pentahydroxypregnan-1,4-diene-3-one (M-IX), and 6β,11β,17α,21-tetrahydroxy-5ξ-pregn-1-en-3,20-dione (M-XIV). MVIII is metabolized to 6β,11β,17α,20β,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XV) and then to MXIV, while MIX is metabolized to 6β,11β,17α,20α,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XVI) and then to MXIV. These metabolites and their glucuronide conjugates are excreted predominantly in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prednisolone is over 98% eliminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Prednisolone has a plasma half life of 2.1-3.5 hours. This half life is shorter in children and longer in those with liver disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): A 0.15mg/kg dose of prednisolone has a clearance of 0.09L/kg/h, while a 0.30mg/kg dose has a clearance of 0.12L/kg/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The intraperitoneal LD 50 in rats is 2g/kg and 65mg/kg in mice. The subcutaneous LD 50 in rats is 147mg/kg and >3500mg/kg in mice. The oral LD 50 in mice is 1680mg/kg. In humans, the oral TDLO in men is 9mg/kg/2W and in women is 14mg/kg/13D. Patients experiencing an overdose of prednisolone may present with gastrointestinal disturbances, insomnia, and restlessness. Overdose of oral prednisolone may be treated by gastric lavage or inducing vomiting if the overdose was recent, as well as supportive and symptomatic therapy. Chronic overdosage may be treated by dose reduction or treating patients on alternate days. An overdose by the ophthalmic route is not expected to cause problems. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Millipred Dp 6 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): delta-dehydrocortisol delta-dehydrohydrocortisone delta-hydrocortisone delta(1)-Dehydrocortisol delta(1)-Hydrocortisone Hydroretrocortine Metacortandralone PRDL Prednisolona Prednisolone Prednisolonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prednisolone is a glucocorticoid used to treat adrenocortical insufficiency, inflammatory conditions, and some cancers. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Prednisone interact?

•Drug A: Abatacept •Drug B: Prednisone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Prednisone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Prednisone is indicated as an anti-inflammatory or immunosuppressive drug for allergic, dermatologic, gastrointestinal, hematologic, ophthalmologic, nervous system, renal, respiratory, rheumatologic, infectious, endocrine, or neoplastic conditions as well as in organ transplant. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisone has a short duration of action as the half life is 2-3 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Prednisone is first metabolized in the liver to its active form, prednisolone, a glucocorticoid agonist corticosteroid. The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral prednisone has a T max of 2 hours, while the delayed-release formulation has a T max of 6-6.5 hours. A 5mg dose of prednisone has an AUC of 572mL/min/1.73m, a 20mg dose of prednisone has an AUC of 1034mL/min/1.73m, and a 50mg dose of prednisone has an AUC of 2271mL/min/1.73m. Data regarding the C max of prednisone is not readily available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Data regarding the volume of distribution for prednisone is not readily available. However, a 0.15mg/kg dose of prednisolone has a volume of distribution of 29.3L, while a 0.30mg/kg dose has a volume of distribution of 44.2L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. Prednisone is <50% bound to protein in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prednisone is metabolized to 17α,21-dihydroxy-pregnan-1,4,6-trien-3,11,30-trione (M-XVII), 20α-dihydro-prednisone (M-V), 6βhydroxy-prednisone (M-XII), 6α-hydroxy-prednisone (M-XIII), or 20β-dihydro-prednisone (M-IV). 20β-dihydro-prednisone is metabolized to 17α,20ξ,21-trihydroxy-5ξ-pregn-1-en-3,11-dione(M-XVIII). Prednison is reversibly metabolized to prednisolone. Prednisolone is metabolized to Δ6-prednisolone (M-XI), 20α-dihydro-prednisolone (M-III), 20β-dihydro-prednisolone (M-II), 6αhydroxy-prednisolone (M-VII), or 6βhydroxy-prednisolone(M-VI). 6αhydroxy-prednisolone is metabolized to 6α,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-X). 6βhydroxy-prednisolone is metabolized to 6β,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-VIII), 6β,11β,17α,20α,21-pentahydroxypregnan-1,4-diene-3-one (M-IX), and 6β,11β,17α,21-tetrahydroxy-5ξ-pregn-1-en-3,20-dione (M-XIV). MVIII is metabolized to 6β,11β,17α,20β,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XV) and then to MXIV, while MIX is metabolized to 6β,11β,17α,20α,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XVI) and then to MXIV. These metabolites and their glucuronide conjugates are excreted predominantly in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prednisone is excreted mainly in the urine as sulfate and glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Prednisone and its active metabolite prednisolone have half lives of 2-3 hours from both immediate and delayed release preparations. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of prednisone is not readily available. A 5.5µg/h/kg infusion of prednisolone has an average clearance of 0.066±0.12L/h/kg, while a 0.15±0.03L/h/kg infusion has an average clearance of 0.15L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of prednisone are rare but prolonged high doses of prednisone can lead to a higher incidence and severity of adverse effects such as mental symptoms, moon face, abnormal fat deposits, fluid retention, excessive appetite, weight gain, hypertrichosis, acne, striae, ecchymosis, increased sweating, pigmentation, dry scaly skin, thinning scalp hair, increased blood pressure, tachycardia, thrombophlebitis, decreased resistance to infection, negative nitrogen balance with delayed bone and wound healing, headache, weakness, menstrual disorders, accentuated menopausal symptoms, neuropathy, fractures, osteoporosis, peptic ulcer, decreased glucose tolerance, hypokalemia, and adrenal insufficiency. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Deltasone, Rayos, Winpred •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 1,2-Dehydrocortisone Dehydrocortisone Prednisona Prednisone Prednisonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prednisone is a corticosteroid used to treat inflammation or immune-mediated reactions and to treat endocrine or neoplastic diseases.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Prednisone interact? Information: •Drug A: Abatacept •Drug B: Prednisone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Prednisone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Prednisone is indicated as an anti-inflammatory or immunosuppressive drug for allergic, dermatologic, gastrointestinal, hematologic, ophthalmologic, nervous system, renal, respiratory, rheumatologic, infectious, endocrine, or neoplastic conditions as well as in organ transplant. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Prednisone has a short duration of action as the half life is 2-3 hours. Corticosteroids have a wide therapeutic window as patients make require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Prednisone is first metabolized in the liver to its active form, prednisolone, a glucocorticoid agonist corticosteroid. The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral prednisone has a T max of 2 hours, while the delayed-release formulation has a T max of 6-6.5 hours. A 5mg dose of prednisone has an AUC of 572mL/min/1.73m, a 20mg dose of prednisone has an AUC of 1034mL/min/1.73m, and a 50mg dose of prednisone has an AUC of 2271mL/min/1.73m. Data regarding the C max of prednisone is not readily available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Data regarding the volume of distribution for prednisone is not readily available. However, a 0.15mg/kg dose of prednisolone has a volume of distribution of 29.3L, while a 0.30mg/kg dose has a volume of distribution of 44.2L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. Prednisone is <50% bound to protein in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prednisone is metabolized to 17α,21-dihydroxy-pregnan-1,4,6-trien-3,11,30-trione (M-XVII), 20α-dihydro-prednisone (M-V), 6βhydroxy-prednisone (M-XII), 6α-hydroxy-prednisone (M-XIII), or 20β-dihydro-prednisone (M-IV). 20β-dihydro-prednisone is metabolized to 17α,20ξ,21-trihydroxy-5ξ-pregn-1-en-3,11-dione(M-XVIII). Prednison is reversibly metabolized to prednisolone. Prednisolone is metabolized to Δ6-prednisolone (M-XI), 20α-dihydro-prednisolone (M-III), 20β-dihydro-prednisolone (M-II), 6αhydroxy-prednisolone (M-VII), or 6βhydroxy-prednisolone(M-VI). 6αhydroxy-prednisolone is metabolized to 6α,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-X). 6βhydroxy-prednisolone is metabolized to 6β,11β,17α,20β,21-pentahydroxypregnan-1,4-diene-3-one (M-VIII), 6β,11β,17α,20α,21-pentahydroxypregnan-1,4-diene-3-one (M-IX), and 6β,11β,17α,21-tetrahydroxy-5ξ-pregn-1-en-3,20-dione (M-XIV). MVIII is metabolized to 6β,11β,17α,20β,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XV) and then to MXIV, while MIX is metabolized to 6β,11β,17α,20α,21-pentahydroxy-5ξ-pregn-1-en-3-one (M-XVI) and then to MXIV. These metabolites and their glucuronide conjugates are excreted predominantly in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prednisone is excreted mainly in the urine as sulfate and glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Prednisone and its active metabolite prednisolone have half lives of 2-3 hours from both immediate and delayed release preparations. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of prednisone is not readily available. A 5.5µg/h/kg infusion of prednisolone has an average clearance of 0.066±0.12L/h/kg, while a 0.15±0.03L/h/kg infusion has an average clearance of 0.15L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of prednisone are rare but prolonged high doses of prednisone can lead to a higher incidence and severity of adverse effects such as mental symptoms, moon face, abnormal fat deposits, fluid retention, excessive appetite, weight gain, hypertrichosis, acne, striae, ecchymosis, increased sweating, pigmentation, dry scaly skin, thinning scalp hair, increased blood pressure, tachycardia, thrombophlebitis, decreased resistance to infection, negative nitrogen balance with delayed bone and wound healing, headache, weakness, menstrual disorders, accentuated menopausal symptoms, neuropathy, fractures, osteoporosis, peptic ulcer, decreased glucose tolerance, hypokalemia, and adrenal insufficiency. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Deltasone, Rayos, Winpred •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 1,2-Dehydrocortisone Dehydrocortisone Prednisona Prednisone Prednisonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prednisone is a corticosteroid used to treat inflammation or immune-mediated reactions and to treat endocrine or neoplastic diseases. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Pretomanid interact?

•Drug A: Abatacept •Drug B: Pretomanid •Severity: MODERATE •Description: The metabolism of Pretomanid can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Pretomanid is indicated, as part of a combination regimen with bedaquiline and linezolid, for the treatment of adults with pulmonary tuberculosis (TB) that is resistant to isoniazid, rifamycins, a fluoroquinolone and a second-line injectable antibacterial drug or adults with pulmonary TB resistant to isoniazid and rifampin, who are treatment-intolerant or non-responsive to standard therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Pretomanid kills the actively replicating bacteria causing tuberculosis, known as Mycobacterium tuberculosis, and shortens the duration of treatment in patients who suffer from resistant forms of pulmonary TB by killing dormant bacteria. In rodent models of tuberculosis infection, pretomanid administered in a regimen with bedaquiline and linezolid caused a significant reduction in pulmonary bacterial cell counts. A decrease in the frequency of TB relapses at 2 and 3 months after treatment was observed after the administration of this regimen, when compared to the administration of a 2-drug regimen. Successful outcomes have been recorded for patients with XDR and MDR following a clinical trial of the pretomanid regimen, demonstrating a 90% cure rate after 6 months. A note on cardiac QT prolongation, hepatotoxicity, and myelosuppression This drug has the propensity to caused cardiac QT interval prolongation and significant hepatotoxicity, as well as myelosuppression. Caution must be observed during the administration of this drug. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Pretomanid is a prodrug which is metabolically activated by a nitroreductase enzyme, known as Ddn, producing various active metabolites that are responsible for its other therapeutic actions, particularly the induction of nitric oxide. The nitroreductase enzyme which activates pretomanid is deazaflavin dependent and relies on reduced cofactor F420. Reduction of F420 occurs via the enzyme glucose-6-phosphate dehydrogenase. Reduction of pretomanid's imidazole ring at the C-3 position causes the formation of the metabolites, which include a des-nitro derivative. The formation of this derivative leads to increased levels of nitric oxide, leading to bactericidal activities under anaerobic conditions via its action as a bacterial respiratory poison. Bactericidal activity against anaerobes is reported to be associated with a shortened duration of antibiotic treatment. Pretomanid exerts aerobic bactericidal effects through its inhibitory actions on bacterial cell wall mycolic acid biosynthesis. This allows for the killing of actively replicating Mycobacterium tuberculosis bacteria, resulting in the treatment of active tuberculosis infection. The molecular mechanism of the above bactericidal effects is poorly understood at this time, but may involve effects exerted on various genes that affect the cell wall, including the fasI and fasII as well as the efpA and iniBAC operons. Other possible targets include the genes of the cyd operon. The clinical effects of the above target relations are unknown at this time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): This drug is absorbed in the gastrointestinal tract. The steady-state Cmax of pretomanid was estimated to be 1.7 μg/mL after a single 200mg oral dose. In a separate pharmacokinetic modeling study, the Cmax of a 200mg dose was 1.1 μg/ml. Tmax in a study of healthy subjects in the fed or unfed state was achieved within 4 to 5 hours. The AUC in the same study was found to be about 28.1 μg•hr/mL in the fasted state and about 51.6 μg•hr/mL in the fed state, showing higher absorption when taken with high-calorie and high-fat food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A pharmacokinetic modeling study estimated the volume of distribution at 130 ± 5L. A pharmacokinetic study in healthy volunteers determined a volume of distribution of about 180 ± 51.3L in fasted state and 97.0 ± 17.2L in the fed state. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of pretomanid is about 86.4%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Various reductive and oxidative pathways are responsible for pretomanid metabolism, with no single major metabolic pathway identified. According to in vitro studies, CYP3A4 is responsible for a 20% contribution to the metabolism of pretomanid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Healthy adult male volunteers were administered a 1,100 mg oral dose of radiolabeled pretomanid in one pharmacokinetic study. An average of about 53% of the radioactive dose was found to be excreted in the urine. Approximately 38% was measured mainly as metabolites in the feces. A estimated 1% of the radiolabeled dose was measured as unchanged drug in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life was determined to be 16.9-17.4 hours in a pharmacokinetic study of healthy subjects. An FDA briefing document reports a half-life of 18 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of pretomanid in a pharmacokinetic simulation study has been estimated at 4.8 ± 0.2 liters/h. According to the FDA label, the clearance of a single 200 mg oral dose of pretomanid is estimated to be 7.6 liters/h in the fasted state, and 3.9 liters/h in the fed state. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): To this date, there is no documented experience with the treatment of a pretomanid overdose. The FDA label advises that general supportive measures are taken to manage an overdose, such as monitoring vital signs in addition to performing ECG testing for a prolonged QT interval in the case of an overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Pretomanid is part of a three-drug regimen used for the treatment of extensively drug-resistant and multidrug-resistant pulmonary tuberculosis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Pretomanid interact? Information: •Drug A: Abatacept •Drug B: Pretomanid •Severity: MODERATE •Description: The metabolism of Pretomanid can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Pretomanid is indicated, as part of a combination regimen with bedaquiline and linezolid, for the treatment of adults with pulmonary tuberculosis (TB) that is resistant to isoniazid, rifamycins, a fluoroquinolone and a second-line injectable antibacterial drug or adults with pulmonary TB resistant to isoniazid and rifampin, who are treatment-intolerant or non-responsive to standard therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Pretomanid kills the actively replicating bacteria causing tuberculosis, known as Mycobacterium tuberculosis, and shortens the duration of treatment in patients who suffer from resistant forms of pulmonary TB by killing dormant bacteria. In rodent models of tuberculosis infection, pretomanid administered in a regimen with bedaquiline and linezolid caused a significant reduction in pulmonary bacterial cell counts. A decrease in the frequency of TB relapses at 2 and 3 months after treatment was observed after the administration of this regimen, when compared to the administration of a 2-drug regimen. Successful outcomes have been recorded for patients with XDR and MDR following a clinical trial of the pretomanid regimen, demonstrating a 90% cure rate after 6 months. A note on cardiac QT prolongation, hepatotoxicity, and myelosuppression This drug has the propensity to caused cardiac QT interval prolongation and significant hepatotoxicity, as well as myelosuppression. Caution must be observed during the administration of this drug. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Pretomanid is a prodrug which is metabolically activated by a nitroreductase enzyme, known as Ddn, producing various active metabolites that are responsible for its other therapeutic actions, particularly the induction of nitric oxide. The nitroreductase enzyme which activates pretomanid is deazaflavin dependent and relies on reduced cofactor F420. Reduction of F420 occurs via the enzyme glucose-6-phosphate dehydrogenase. Reduction of pretomanid's imidazole ring at the C-3 position causes the formation of the metabolites, which include a des-nitro derivative. The formation of this derivative leads to increased levels of nitric oxide, leading to bactericidal activities under anaerobic conditions via its action as a bacterial respiratory poison. Bactericidal activity against anaerobes is reported to be associated with a shortened duration of antibiotic treatment. Pretomanid exerts aerobic bactericidal effects through its inhibitory actions on bacterial cell wall mycolic acid biosynthesis. This allows for the killing of actively replicating Mycobacterium tuberculosis bacteria, resulting in the treatment of active tuberculosis infection. The molecular mechanism of the above bactericidal effects is poorly understood at this time, but may involve effects exerted on various genes that affect the cell wall, including the fasI and fasII as well as the efpA and iniBAC operons. Other possible targets include the genes of the cyd operon. The clinical effects of the above target relations are unknown at this time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): This drug is absorbed in the gastrointestinal tract. The steady-state Cmax of pretomanid was estimated to be 1.7 μg/mL after a single 200mg oral dose. In a separate pharmacokinetic modeling study, the Cmax of a 200mg dose was 1.1 μg/ml. Tmax in a study of healthy subjects in the fed or unfed state was achieved within 4 to 5 hours. The AUC in the same study was found to be about 28.1 μg•hr/mL in the fasted state and about 51.6 μg•hr/mL in the fed state, showing higher absorption when taken with high-calorie and high-fat food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A pharmacokinetic modeling study estimated the volume of distribution at 130 ± 5L. A pharmacokinetic study in healthy volunteers determined a volume of distribution of about 180 ± 51.3L in fasted state and 97.0 ± 17.2L in the fed state. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of pretomanid is about 86.4%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Various reductive and oxidative pathways are responsible for pretomanid metabolism, with no single major metabolic pathway identified. According to in vitro studies, CYP3A4 is responsible for a 20% contribution to the metabolism of pretomanid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Healthy adult male volunteers were administered a 1,100 mg oral dose of radiolabeled pretomanid in one pharmacokinetic study. An average of about 53% of the radioactive dose was found to be excreted in the urine. Approximately 38% was measured mainly as metabolites in the feces. A estimated 1% of the radiolabeled dose was measured as unchanged drug in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life was determined to be 16.9-17.4 hours in a pharmacokinetic study of healthy subjects. An FDA briefing document reports a half-life of 18 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of pretomanid in a pharmacokinetic simulation study has been estimated at 4.8 ± 0.2 liters/h. According to the FDA label, the clearance of a single 200 mg oral dose of pretomanid is estimated to be 7.6 liters/h in the fasted state, and 3.9 liters/h in the fed state. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): To this date, there is no documented experience with the treatment of a pretomanid overdose. The FDA label advises that general supportive measures are taken to manage an overdose, such as monitoring vital signs in addition to performing ECG testing for a prolonged QT interval in the case of an overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Pretomanid is part of a three-drug regimen used for the treatment of extensively drug-resistant and multidrug-resistant pulmonary tuberculosis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Does Abatacept and Primaquine interact?

•Drug A: Abatacept •Drug B: Primaquine •Severity: MODERATE •Description: The metabolism of Primaquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malaria. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Primaquine is an antimalarial agent and is the essential co-drug with chloroquine in treating all cases of malaria. In the blood, malaria parasites break down a part of the red blood cells known as haemoglobin. When this happens haemoglobin is divided into two parts; haem and globin. Haem is toxic to the malaria parasite. To prevent it from being damaged, the malaria parasite produces an chemical which converts the toxic haem into a non-toxic product. Primaquine acts by interfering with a part of the parasite (mitochondria) that is responsible for supplying it with energy. Without energy the parasite dies. This stops the infection from continuing and allows the person to recover. Primaquine kills the intrahepatic form of Plasmodium vivax and Plasmodium ovale, and thereby prevents the development of the erythrocytic forms that are responsible for relapses (it also kills gametocytes). Primaquine is not used in the prevention of malaria, only in the treatment. It has insignificant activity against the asexual blood forms of the parasite and therefore it is always used in conjunction with a blood schizonticide and never as a single agent. Primaquine has gametocytocidal activity against all plasmodia, including P. falciparum. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Primaquine's mechanism of action is not well understood. It may be acting by generating reactive oxygen species or by interfering with the electron transport in the parasite. Also, although its mechanism of action is unclear, primaquine may bind to and alter the properties of protozoal DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3.7-7.4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Primachin Primachina Primachinum Primaquin Primaquina Primaquine Primaquinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Primaquine is an antimalarial indicated to prevent relapse of vivax malaria.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Primaquine interact? Information: •Drug A: Abatacept •Drug B: Primaquine •Severity: MODERATE •Description: The metabolism of Primaquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malaria. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Primaquine is an antimalarial agent and is the essential co-drug with chloroquine in treating all cases of malaria. In the blood, malaria parasites break down a part of the red blood cells known as haemoglobin. When this happens haemoglobin is divided into two parts; haem and globin. Haem is toxic to the malaria parasite. To prevent it from being damaged, the malaria parasite produces an chemical which converts the toxic haem into a non-toxic product. Primaquine acts by interfering with a part of the parasite (mitochondria) that is responsible for supplying it with energy. Without energy the parasite dies. This stops the infection from continuing and allows the person to recover. Primaquine kills the intrahepatic form of Plasmodium vivax and Plasmodium ovale, and thereby prevents the development of the erythrocytic forms that are responsible for relapses (it also kills gametocytes). Primaquine is not used in the prevention of malaria, only in the treatment. It has insignificant activity against the asexual blood forms of the parasite and therefore it is always used in conjunction with a blood schizonticide and never as a single agent. Primaquine has gametocytocidal activity against all plasmodia, including P. falciparum. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Primaquine's mechanism of action is not well understood. It may be acting by generating reactive oxygen species or by interfering with the electron transport in the parasite. Also, although its mechanism of action is unclear, primaquine may bind to and alter the properties of protozoal DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3.7-7.4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Primachin Primachina Primachinum Primaquin Primaquina Primaquine Primaquinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Primaquine is an antimalarial indicated to prevent relapse of vivax malaria. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Primidone interact?

•Drug A: Abatacept •Drug B: Primidone •Severity: MODERATE •Description: The metabolism of Primidone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Primidone is commonly indicated for the management of grand mal, psychomotor, and focal epileptic seizures. In addition, it has also been studied and utilized as an effective management of essential tremor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Primidone alters sodium and calcium channel transport, reducing the frequency of nerve firing, which may be responsible for its effect on convulsions and essential tremor. Primidone has a wide therapeutic window as doses of 50-1000mg/day were effective. Patients should be counselled regarding the risk of status epilepticus with abrupt cessation of primidone. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Primidone and its metabolites, phenobarbital and phenylethylmalonamide (PEMA), are active anticonvulsants. Primidone does not directly interact with GABA-A receptors or chloride channels but phenobarbital does. Primidone alters transmembrane sodium and calcium channel transport, reducing the frequency of nerve firing, which may be responsible for the primidone’s effect on convulsions and essential tremor. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral primidone is up to 80% bioavailable with a T max if 2-4h. A 500mg oral dose of primidone Reaches a C max of 2.7±0.4µg/mL with a T max of 0.5-7h. Data regarding the AUC of primidone is not readily available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of primidone is 0.5-0.8L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Primidone is 10.78-13.70% protein bound in serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primidone is metabolized to phenobarbitol and phenylethylmalonamide (PEMA). This metabolism is largely mediated by CYP2C9, CYP2C19, and CYP2E1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Primidone is 72.9-80.6% recovered in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of primidone is 7-22h in adults, 5-11h in children, and 8-80h in newborns. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Primidone is cleared at a rate of 30mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in rats is 1500mg/kg and in mice is 280mg/kg. The intraperitoneal LD 50 in rats was 240mg/kg and in mice was 332mg/kg. Patients experiencing a primidone overdose may present with CNS depression, coma, respiratory depression, suppressed reflexes, suppressed response to pain, hypotension, and decreased urine output. Overdose should be treated with symptomatic and supportive treatment, including the removal of unabsorbed drug. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mysoline •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-deoxyphenobarbital Primidon Primidona Primidone Primidonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Primidone is an antiepileptic used to treat grand mal, psychomotor, and focal epileptic seizures.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Primidone interact? Information: •Drug A: Abatacept •Drug B: Primidone •Severity: MODERATE •Description: The metabolism of Primidone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Primidone is commonly indicated for the management of grand mal, psychomotor, and focal epileptic seizures. In addition, it has also been studied and utilized as an effective management of essential tremor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Primidone alters sodium and calcium channel transport, reducing the frequency of nerve firing, which may be responsible for its effect on convulsions and essential tremor. Primidone has a wide therapeutic window as doses of 50-1000mg/day were effective. Patients should be counselled regarding the risk of status epilepticus with abrupt cessation of primidone. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Primidone and its metabolites, phenobarbital and phenylethylmalonamide (PEMA), are active anticonvulsants. Primidone does not directly interact with GABA-A receptors or chloride channels but phenobarbital does. Primidone alters transmembrane sodium and calcium channel transport, reducing the frequency of nerve firing, which may be responsible for the primidone’s effect on convulsions and essential tremor. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral primidone is up to 80% bioavailable with a T max if 2-4h. A 500mg oral dose of primidone Reaches a C max of 2.7±0.4µg/mL with a T max of 0.5-7h. Data regarding the AUC of primidone is not readily available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of primidone is 0.5-0.8L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Primidone is 10.78-13.70% protein bound in serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primidone is metabolized to phenobarbitol and phenylethylmalonamide (PEMA). This metabolism is largely mediated by CYP2C9, CYP2C19, and CYP2E1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Primidone is 72.9-80.6% recovered in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of primidone is 7-22h in adults, 5-11h in children, and 8-80h in newborns. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Primidone is cleared at a rate of 30mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in rats is 1500mg/kg and in mice is 280mg/kg. The intraperitoneal LD 50 in rats was 240mg/kg and in mice was 332mg/kg. Patients experiencing a primidone overdose may present with CNS depression, coma, respiratory depression, suppressed reflexes, suppressed response to pain, hypotension, and decreased urine output. Overdose should be treated with symptomatic and supportive treatment, including the removal of unabsorbed drug. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mysoline •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-deoxyphenobarbital Primidon Primidona Primidone Primidonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Primidone is an antiepileptic used to treat grand mal, psychomotor, and focal epileptic seizures. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Procainamide interact?

•Drug A: Abatacept •Drug B: Procainamide •Severity: MAJOR •Description: The metabolism of Procainamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of life-threatening ventricular arrhythmias. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Procainamide is an agent indicated for production of local or regional anesthesia and in the treatment of ventricular tachycardia occurring during cardiac manipulation, such as surgery or catheterization, or which may occur during acute myocardial infarction, digitalis toxicity, or other cardiac diseases. The mode of action of the antiarrhythmic effect of Procainamide appears to be similar to that of procaine and quinidine. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. The sinoatrial node is, however, unaffected. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Procainamide is sodium channel blocker. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 75 to 95% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 15 to 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Trace amounts may be excreted in the urine as free and conjugated p-aminobenzoic acid, 30 to 60 percent as unchanged PA, and 6 to 52 percent as the NAPA derivative. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~2.5-4.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =95 mg/kg (rat, IV); LD 50 =312 mg/kg (mouse, oral); LD 50 =103 mg/kg (mouse, IV); LD 50 =250 mg/kg (rabbit, IV) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Procan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Procainamida Procainamide Procaïnamide Procainamidum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Procainamide is a medication used to treat life threatening ventricular arrhythmias.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Procainamide interact? Information: •Drug A: Abatacept •Drug B: Procainamide •Severity: MAJOR •Description: The metabolism of Procainamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of life-threatening ventricular arrhythmias. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Procainamide is an agent indicated for production of local or regional anesthesia and in the treatment of ventricular tachycardia occurring during cardiac manipulation, such as surgery or catheterization, or which may occur during acute myocardial infarction, digitalis toxicity, or other cardiac diseases. The mode of action of the antiarrhythmic effect of Procainamide appears to be similar to that of procaine and quinidine. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. The sinoatrial node is, however, unaffected. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Procainamide is sodium channel blocker. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 75 to 95% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 15 to 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Trace amounts may be excreted in the urine as free and conjugated p-aminobenzoic acid, 30 to 60 percent as unchanged PA, and 6 to 52 percent as the NAPA derivative. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~2.5-4.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =95 mg/kg (rat, IV); LD 50 =312 mg/kg (mouse, oral); LD 50 =103 mg/kg (mouse, IV); LD 50 =250 mg/kg (rabbit, IV) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Procan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Procainamida Procainamide Procaïnamide Procainamidum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Procainamide is a medication used to treat life threatening ventricular arrhythmias. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Procarbazine interact?

•Drug A: Abatacept •Drug B: Procarbazine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Procarbazine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use with other anticancer drugs for the treatment of stage III and stage IV Hodgkin's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Procarbazine is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Procarbazine is cell-phase specific for the S phase of cell division. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mode of cytotoxic action of procarbazine has not been clearly defined. There is evidence that the drug may act by inhibition of protein, RNA and DNA synthesis. Studies have suggested that procarbazine may inhibit transmethylation of methyl groups of methionine into t-RNA. The absence of functional t-RNA could cause the cessation of protein synthesis and consequently DNA and RNA synthesis. In addition, procarbazine may directly damage DNA. Hydrogen peroxide, formed during the auto-oxidation of the drug, may attack protein sulfhydryl groups contained in residual protein which is tightly bound to DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Procarbazine is rapidly and completely absorbed. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Procarbazine is metabolized primarily in the liver and kidneys. The drug appears to be auto-oxidized to the azo derivative with the release of hydrogen peroxide. The azo derivative isomerizes to the hydrazone, and following hydrolysis splits into a benzylaldehyde derivative and methylhydrazine. The methylhydrazine is further degraded to CO 2 and CH 4 and possibly hydrazine, whereas the aldehyde is oxidized to N-isopropylterephthalamic acid, which is excreted in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 10 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =785 mg/kg (orally in rats) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Matulane •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Procarbazin Procarbazina Procarbazine Procarbazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Procarbazine is an antineoplastic agent indicated for the treatment of stage III and stage IV Hodgkin's disease in combination with other chemotherapeutic agents.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Procarbazine interact? Information: •Drug A: Abatacept •Drug B: Procarbazine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Procarbazine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use with other anticancer drugs for the treatment of stage III and stage IV Hodgkin's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Procarbazine is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Procarbazine is cell-phase specific for the S phase of cell division. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mode of cytotoxic action of procarbazine has not been clearly defined. There is evidence that the drug may act by inhibition of protein, RNA and DNA synthesis. Studies have suggested that procarbazine may inhibit transmethylation of methyl groups of methionine into t-RNA. The absence of functional t-RNA could cause the cessation of protein synthesis and consequently DNA and RNA synthesis. In addition, procarbazine may directly damage DNA. Hydrogen peroxide, formed during the auto-oxidation of the drug, may attack protein sulfhydryl groups contained in residual protein which is tightly bound to DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Procarbazine is rapidly and completely absorbed. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Procarbazine is metabolized primarily in the liver and kidneys. The drug appears to be auto-oxidized to the azo derivative with the release of hydrogen peroxide. The azo derivative isomerizes to the hydrazone, and following hydrolysis splits into a benzylaldehyde derivative and methylhydrazine. The methylhydrazine is further degraded to CO 2 and CH 4 and possibly hydrazine, whereas the aldehyde is oxidized to N-isopropylterephthalamic acid, which is excreted in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 10 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =785 mg/kg (orally in rats) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Matulane •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Procarbazin Procarbazina Procarbazine Procarbazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Procarbazine is an antineoplastic agent indicated for the treatment of stage III and stage IV Hodgkin's disease in combination with other chemotherapeutic agents. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Prochlorperazine interact?

•Drug A: Abatacept •Drug B: Prochlorperazine •Severity: MODERATE •Description: The metabolism of Prochlorperazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for the symptomatic treatment of severe nausea and vomiting. Indicated for the management of manifestations of psychotic disorders, such as schizophrenia and generalized non-psychotic anxiety. The use of prochlorperazine for the management of generalized non-psychotic anxiety is typically not a first-line therapy and should be limited to doses of less than 20 mg per day or for shorter than 12 weeks. Off-label uses include use in emergency settings for adult and pediatric migraines. The American Headache Society recommends the use of prochlorperazine as the first-line medication in this setting. In pediatric migraines, a non-steroidal anti-inflammatory agent is often used in combination with dopamine antagonist. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Prochlorperazine is an antipsychotic agent that works to promote postsynaptic inhibition of dopaminergic neurons. It also exerts its anti-emetic actions via anti-dopaminergic effects, where it displays similar efficacy as ondansteron, a 5HT-3 receptor antagonist and anti-emetic, in preventing delayed nausea and vomiting. Prochlorperazine was shown to inhibit histaminergic, cholinergic and alpha-1 adrenergic receptors. The blockade of alpha-1 adrenergic receptors may result in sedation, muscle relaxation, and hypotension. It displays anti-anxiety effects as well. Compared to other phenothiazine derivatives, prochlorperazine is less sedating and has a weak propensity for causing hypotension or potentiating the effects of CNS depressants and anesthetics. Other than its primary action on D2 receptors, one study showed that prochlorperazine may inhibit the P2X7 receptor in human macrophages, leading to inhibition of calcium ion influx. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of prochlorperazine has not been fully determined, but may be primarily related to its anti-dopaminergic effects. Prochlorperazine blocks the D2 dopamine receptors in the brain, which are somatodendritic autoreceptors. Inhibition of D2 receptor signaling results in the blockade of postsynaptic dopamine receptors in the mesolimbic system and an increased dopamine turnover. Nausea and vomiting are proposed to arise from peripheral or central stimulation of serotonin type 3 (5-HT3) and dopamine type 2 receptors, the predominant receptors expressed at the chemoreceptor trigger zone (CTZ). Prochlorperazine exerts antiemetic effects and was shown to inhibit apomorphine-induced vomiting by blocking D2 dopamine receptors in the CTZ.. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, prochlorperazine is reported to be well absorbed from the gastrointestinal tract. The onset of pharmacological action is about 30 to 40 minutes following oral administration and 10 to 20 minutes following intramuscular administration. The duration of action for all routes is about 3 to 4 hours. Following oral administration in healthy volunteers, the mean oral bioavailability was about 12.5%. In these patients, the time to reach the peak plasma concentrations was about 5 hours. Repeated oral dosing resulted in an accumulation of prochlorperazine and its metabolite. Following multiple twice daily dosing, the steady state of prochlorperazine was reached by 7 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In a preliminary pharmacokinetic study involving healthy volunteers, the mean apparent volume of distribution following intravenous administration of 6.25 mg and 12.5 mg prochlorperazine were approximately 1401 L and 1548 L, respectively. Prochlorperazine is reported to be distributed to most body tissues with high concentrations being distributed into liver and spleen. There is evidence that phenothiazines are excreted in the breast milk of nursing mothers. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is limited data on protein binding of prochlorperazine. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prochlorperazine undergoes hepatic metabolism involving oxidation, hydroxylation, demethylation, sulfoxide formation and conjugation with glucuronic acid. The oxidation reaction is mediated by CYP2D6. N-desmethyl prochlorperazine was detected in the plasma, as well as prochlorperazine sulfoxide, prochlorperazine 7-hydroxide and prochlorperazine sulfoxide 4'-N-oxide, following oral and buccal administration. Prochlorperazine may enter the enterohepatic circulation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prochlorperazine is reported to be mainly excreted via the feces and bile. Low quantities of unchanged prochlorperazine and its metabolite were detectable in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following intravenous and single oral dose administration, the terminal elimination half live were 9 and 8 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean plasma clearance (CL) of prochlorperazine following intravenous administration in healthy volunteers was approximately 0.98L/h x kg. The mean renal clearance was about 23.6 mL/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 and Overdose Oral LD 50 in rats is 750 mg/kg. Intraperitoneal and subcutaneous LD 50 in mice are 191 mg/kg and 320 mg/kg, respectively. In placebo-controlled trials, there were increased incidences of mortality in elderly patients with dementia-related psychosis receiving antipsychotic medications. The risk of death in drug-treated patients was about 1.6 to 1.7 times that of placebo-treated patients. Deaths were largely resulting from cardiovascular, such as heart failure and sudden death, or infectious, such as pneumonia, conditions. Due to its antagonist action on dopamine receptors, prochlorperazine is associated with a risk for developing extrapyramidal symptoms such as tardive dyskinesia, which is a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements. This risk is also conferred on other antipsychotic agents that block dopamine receptors. It is proposed that increased duration of the drug treatment is likely thus increased total cumulative dose of antipsychotic drugs administered to the patient leads to increased risk for developing the syndrome and the likelihood that it will become irreversible. As with other antipsychotic agents, prochlorperazine is associated with a risk for causing neuroleptic malignant syndrome (NMS), which is a potentially fatal symptom complex, which is manifested as hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability. There is no known antidote for prochlorperazine thus overdose treatment should be supportive and symptomatic. Overdose of prochlorperazine may produce dystonic reactions that involve extrapyramidal mechanism. To reduce these symptoms, antiparkinsonism drugs, barbiturates, or diphenhydramine may be used. Symptoms of central nervous system depression, such as somnolence or coma, may also be observed. Amphetamine, destroamphetamine, or caffeine and sodium benzoate may be used to induce stimulatory effects. In contrast, agitation and restlessness may also be seen in case of overdose. Other possible manifestations include convulsions, EKG changes and cardiac arrhythmias, fever, and autonomic reactions such as hypotension, dry mouth and ileus. Hypotension can be responded with the standard measures for managing circulatory shock. Nonclinical Toxicology In a rat developmental or reproductive toxicity study, abnormalities in both the reproductive measures and neurobehavioral testing were observed following administration of 25 mg/kg of prochlorperazine. Use in specific populations As the use of antipsychotic agents during the third trimester of pregnancy is associated with a risk for extrapyramidal and/or withdrawal symptoms following delivery, the use of prochlorperazine in pregnant patients is generally not recommended and it should be limited after careful consideration of the potential benefit of drug therapy justifying the potential risk to the fetus. Caution should be exercised when prochlorperazine is administered to a nursing mother. While lower doses of prochlorperazine is reported to be safe for elderly patients, caution is still advised, especially those with higher susceptibility to hypotension and neuromuscular reactions. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Compazine, Compro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capazine Chlormeprazine Chloropernazine Prochlorperazin Prochlorpérazine Prochlorperazine Prochlorperazinum Prochlorpermazine Prochlorpromazine Procloperazine Proclorperazina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prochlorperazine is a phenothiazine derivative used in the treatment of schizophrenia and anxiety and to relieve severe nausea and vomiting.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Prochlorperazine interact? Information: •Drug A: Abatacept •Drug B: Prochlorperazine •Severity: MODERATE •Description: The metabolism of Prochlorperazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for the symptomatic treatment of severe nausea and vomiting. Indicated for the management of manifestations of psychotic disorders, such as schizophrenia and generalized non-psychotic anxiety. The use of prochlorperazine for the management of generalized non-psychotic anxiety is typically not a first-line therapy and should be limited to doses of less than 20 mg per day or for shorter than 12 weeks. Off-label uses include use in emergency settings for adult and pediatric migraines. The American Headache Society recommends the use of prochlorperazine as the first-line medication in this setting. In pediatric migraines, a non-steroidal anti-inflammatory agent is often used in combination with dopamine antagonist. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Prochlorperazine is an antipsychotic agent that works to promote postsynaptic inhibition of dopaminergic neurons. It also exerts its anti-emetic actions via anti-dopaminergic effects, where it displays similar efficacy as ondansteron, a 5HT-3 receptor antagonist and anti-emetic, in preventing delayed nausea and vomiting. Prochlorperazine was shown to inhibit histaminergic, cholinergic and alpha-1 adrenergic receptors. The blockade of alpha-1 adrenergic receptors may result in sedation, muscle relaxation, and hypotension. It displays anti-anxiety effects as well. Compared to other phenothiazine derivatives, prochlorperazine is less sedating and has a weak propensity for causing hypotension or potentiating the effects of CNS depressants and anesthetics. Other than its primary action on D2 receptors, one study showed that prochlorperazine may inhibit the P2X7 receptor in human macrophages, leading to inhibition of calcium ion influx. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of prochlorperazine has not been fully determined, but may be primarily related to its anti-dopaminergic effects. Prochlorperazine blocks the D2 dopamine receptors in the brain, which are somatodendritic autoreceptors. Inhibition of D2 receptor signaling results in the blockade of postsynaptic dopamine receptors in the mesolimbic system and an increased dopamine turnover. Nausea and vomiting are proposed to arise from peripheral or central stimulation of serotonin type 3 (5-HT3) and dopamine type 2 receptors, the predominant receptors expressed at the chemoreceptor trigger zone (CTZ). Prochlorperazine exerts antiemetic effects and was shown to inhibit apomorphine-induced vomiting by blocking D2 dopamine receptors in the CTZ.. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, prochlorperazine is reported to be well absorbed from the gastrointestinal tract. The onset of pharmacological action is about 30 to 40 minutes following oral administration and 10 to 20 minutes following intramuscular administration. The duration of action for all routes is about 3 to 4 hours. Following oral administration in healthy volunteers, the mean oral bioavailability was about 12.5%. In these patients, the time to reach the peak plasma concentrations was about 5 hours. Repeated oral dosing resulted in an accumulation of prochlorperazine and its metabolite. Following multiple twice daily dosing, the steady state of prochlorperazine was reached by 7 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In a preliminary pharmacokinetic study involving healthy volunteers, the mean apparent volume of distribution following intravenous administration of 6.25 mg and 12.5 mg prochlorperazine were approximately 1401 L and 1548 L, respectively. Prochlorperazine is reported to be distributed to most body tissues with high concentrations being distributed into liver and spleen. There is evidence that phenothiazines are excreted in the breast milk of nursing mothers. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is limited data on protein binding of prochlorperazine. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Prochlorperazine undergoes hepatic metabolism involving oxidation, hydroxylation, demethylation, sulfoxide formation and conjugation with glucuronic acid. The oxidation reaction is mediated by CYP2D6. N-desmethyl prochlorperazine was detected in the plasma, as well as prochlorperazine sulfoxide, prochlorperazine 7-hydroxide and prochlorperazine sulfoxide 4'-N-oxide, following oral and buccal administration. Prochlorperazine may enter the enterohepatic circulation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Prochlorperazine is reported to be mainly excreted via the feces and bile. Low quantities of unchanged prochlorperazine and its metabolite were detectable in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following intravenous and single oral dose administration, the terminal elimination half live were 9 and 8 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean plasma clearance (CL) of prochlorperazine following intravenous administration in healthy volunteers was approximately 0.98L/h x kg. The mean renal clearance was about 23.6 mL/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 and Overdose Oral LD 50 in rats is 750 mg/kg. Intraperitoneal and subcutaneous LD 50 in mice are 191 mg/kg and 320 mg/kg, respectively. In placebo-controlled trials, there were increased incidences of mortality in elderly patients with dementia-related psychosis receiving antipsychotic medications. The risk of death in drug-treated patients was about 1.6 to 1.7 times that of placebo-treated patients. Deaths were largely resulting from cardiovascular, such as heart failure and sudden death, or infectious, such as pneumonia, conditions. Due to its antagonist action on dopamine receptors, prochlorperazine is associated with a risk for developing extrapyramidal symptoms such as tardive dyskinesia, which is a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements. This risk is also conferred on other antipsychotic agents that block dopamine receptors. It is proposed that increased duration of the drug treatment is likely thus increased total cumulative dose of antipsychotic drugs administered to the patient leads to increased risk for developing the syndrome and the likelihood that it will become irreversible. As with other antipsychotic agents, prochlorperazine is associated with a risk for causing neuroleptic malignant syndrome (NMS), which is a potentially fatal symptom complex, which is manifested as hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability. There is no known antidote for prochlorperazine thus overdose treatment should be supportive and symptomatic. Overdose of prochlorperazine may produce dystonic reactions that involve extrapyramidal mechanism. To reduce these symptoms, antiparkinsonism drugs, barbiturates, or diphenhydramine may be used. Symptoms of central nervous system depression, such as somnolence or coma, may also be observed. Amphetamine, destroamphetamine, or caffeine and sodium benzoate may be used to induce stimulatory effects. In contrast, agitation and restlessness may also be seen in case of overdose. Other possible manifestations include convulsions, EKG changes and cardiac arrhythmias, fever, and autonomic reactions such as hypotension, dry mouth and ileus. Hypotension can be responded with the standard measures for managing circulatory shock. Nonclinical Toxicology In a rat developmental or reproductive toxicity study, abnormalities in both the reproductive measures and neurobehavioral testing were observed following administration of 25 mg/kg of prochlorperazine. Use in specific populations As the use of antipsychotic agents during the third trimester of pregnancy is associated with a risk for extrapyramidal and/or withdrawal symptoms following delivery, the use of prochlorperazine in pregnant patients is generally not recommended and it should be limited after careful consideration of the potential benefit of drug therapy justifying the potential risk to the fetus. Caution should be exercised when prochlorperazine is administered to a nursing mother. While lower doses of prochlorperazine is reported to be safe for elderly patients, caution is still advised, especially those with higher susceptibility to hypotension and neuromuscular reactions. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Compazine, Compro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capazine Chlormeprazine Chloropernazine Prochlorperazin Prochlorpérazine Prochlorperazine Prochlorperazinum Prochlorpermazine Prochlorpromazine Procloperazine Proclorperazina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Prochlorperazine is a phenothiazine derivative used in the treatment of schizophrenia and anxiety and to relieve severe nausea and vomiting. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Progesterone interact?

•Drug A: Abatacept •Drug B: Progesterone •Severity: MODERATE •Description: The metabolism of Progesterone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Gelatinized capsules The gelatinized capsules are indicated for use in the prevention of endometrial hyperplasia in non-hysterectomized postmenopausal women who are receiving conjugated estrogens tablets. They are also indicated for use in secondary amenorrhea. Vaginal gel Progesterone gel (8%) is indicated as progesterone supplementation or replacement as part of an Assisted Reproductive Technology (“ART”) treatment for infertile women with progesterone deficiency. The lower concentration progesterone gel (4%) is used in the treatment of secondary amenorrhea, with the use of the 8% concentration if there is no therapeutic response to the 4% gel. Vaginal insert This form is indicated to support embryo implantation and early pregnancy by supplementation of corpus luteal function as part of an Assisted Reproductive Technology (ART) treatment program for infertile women. Injection (intramuscular) This drug is indicated in amenorrhea and abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as submucous fibroids or uterine cancer. Tablets, contraceptive The tablet form of progesterone in contraceptive formulations is indicated for the prevention of pregnancy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Progesterone, depending on concentration and dosage form, and timing of exposure may have several pharmacodynamic effects. These actions, according, to various preparations, are listed below: General effects Progesterone is the main hormone of the corpus luteum and the placenta. It acts on the uterus by changing the proliferative phase to the secretory phase of the endometrium (inner mucous lining of the uterus). This hormone, stimulated by a hormone called luteinizing hormone (LH) is the main hormone during the secretory phase to prepare the corpus luteum and the endometrium for implantation of a fertilized ovum. As the luteal phase concludes, the progesterone hormone sends negative feedback to the anterior pituitary gland in the brain to decrease FSH (follicle stimulating hormone) and LH (luteinizing hormone) levels. This prevents ovulation and maturation of oocytes (immature egg cells). The endometrium then prepares for pregnancy by increasing its vascularity (blood vessels) and stimulating mucous secretion. This process occurs by progesterone stimulating the endometrium to decrease endometrial proliferation, leading to a decreased uterine lining thickness, developing more complex uterine glands, collecting energy in the form of glycogen, and providing more uterine blood vessel surface area suitable for supporting a growing embryo. As opposed to cervical mucous changes observed during the proliferative phase and ovulation, progesterone decreases and thickens the cervical mucus, rendering it less elastic. This change occurs because the fertilization time period has passed, and a specific consistency of mucous amenable to sperm entry is no longer required. Gelatinized capsules Progesterone capsules are an oral dosage form of micronized progesterone which, chemically identical to progesterone of ovarian origin. Progesterone capsules have all the properties of endogenous progesterone with induction of a secretory phase endometrium with gestagenic, antiestrogenic, slightly antiandrogenic and anti-aldosterone effects. Progesterone opposes the effects of estrogen on the uterus, and is beneficial in women with unopposed estrogen exposure, which carries an increased risk of malignancy. Vaginal gel and vaginal insert The gel preparation mimics the effects of naturally occurring progesterone. In the presence of adequate levels of estrogen, progesterone converts a proliferative endometrium into secretory endometrium. This means that the endometrium changes from a growing and thickening stage into a subsequent preparation stage for pregnancy, which involves further preparatory changes. Progesterone is necessary for the development of decidual tissue (specialized tissue amenable to supporting a possible pregnancy). Progesterone is required to increase endometrial receptivity for the implantation of a fertilized embryo. Once an embryo is implanted, progesterone helps to maintain the pregnancy. Injection (intramuscular) Intramuscularly injected progesterone increases serum progesterone and aids in the prevention of endometrial tissue overgrowth due to unopposed estrogen (which leads to abnormal uterine bleeding and sometimes uterine cancer),. In the absence or deficiency of progesterone, the endometrium continually proliferates, eventually outgrowing its limited blood supply, shedding incompletely, and leading to abnormal and/or profuse bleeding as well as malignancy. Tablets, contraceptive Progesterone-only contraceptive tablets prevent conception by suppressing ovulation in about half of users, causing a thickening of cervical mucus to inhibit sperm movement, lowering the midcycle LH and FSH hormone peaks, slowing the movement of the ovum through the fallopian tubes, and causing secretory changes in the endometrium as described above. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Progesterone binds and activates its nuclear receptor, PR, which plays an important part in the signaling of stimuli that maintain the endometrium during its preparation for pregnancy. Progesterone receptor (PR) is a member of the nuclear/steroid hormone receptor (SHR) family of ligand-dependent transcription factors that is expressed primarily in female reproductive tissue as well as the central nervous system. As a result of its binding its associated steroid hormone, progesterone, the progesterone receptor (PR) modulates the expression of genes that regulate the development, differentiation, and proliferation of target tissues. In humans, PR is found to be highly expressed in the stromal (connective tissue) cells during the secretory phase and during pregnancy. Progesterone may prevent pregnancy by changing the consistency of cervical mucus to be unfavorable for sperm penetration, and by inhibiting follicle-stimulating hormone (FSH), which normally causes ovulation. With perfect use, the first-year failure rate for progestin-only oral contraceptives is approximately 0.5%. The typical failure rate, however, is estimated to be approximately 5%, due to late or missed pills. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral micronized capsules Following oral administration of progesterone in the micronized soft-gelatin capsule formulation, peak serum concentration was achieved in the first 3 hours. The absolute bioavailability of micronized progesterone is unknown at this time. In postmenopausal women, serum progesterone concentration increased in a dose-proportional and linear fashion after multiple doses of progesterone capsules, ranging from 100 mg/day to 300 mg/day. IM administration After intramuscular (IM) administration of 10 mg of progesterone in oil, the maximum plasma concentrations were achieved in about 8 hours post-injection and plasma concentrations stayed above baseline for approximately 24 hours post-injection. Injections of 10, 25, and 50 mg lead to geometric mean values for maximum plasma concentration (CMAX) of 7, 28, and 50 ng/mL, respectively. Progesterone administered by the intramuscular (IM) route avoids significant first-pass hepatic metabolism. As a result, endometrial tissue concentrations of progesterone achieved with IM administration are higher when compared with oral administration. Despite this, the highest concentrations of progesterone in endometrial tissue are reached with vaginal administration. Note on oral contraceptive tablet absorption Serum progestin levels peak about 2 hours after oral administration of progesterone-only contraceptive tablets, followed by rapid distribution and elimination. By 24 hours after drug administration, serum levels remain near the baseline, making efficacy dependent upon strict adherence to the dosing schedule. Large variations in serum progesterone levels occur among individuals. Progestin-only administration leads to lower steady-state serum progestin levels and a shorter elimination half-life than concurrent administration with estrogens. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): When administered vaginally, progesterone is well absorbed by uterine endometrial tissue, and a small percentage is distributed into the systemic circulation. The amount of progesterone in the systemic circulation appears to be of minimal importance, especially when implantation, pregnancy, and live birth outcomes appear similar for intramuscular and vaginal administration of progesterone. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96%-99% bound to serum proteins, primarily to serum albumin (50%-54%) and transcortin (43%-48%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Progesterone is mainly metabolized by the liver. After oral administration, the major plasma metabolites found are 20 a hydroxy-Δ4 a-prenolone and 5 a-dihydroprogesterone. Some progesterone metabolites are found excreted in the bile and these metabolites may be deconjugated and subsequently metabolized in the gut by reduction, dehydroxylation, and epimerization. The major plasma and urinary metabolites are comparable to those found during the physiological progesterone secretion of the corpus luteum. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Progesterone metabolites are excreted mainly by the kidneys. Urinary elimination is observed for 95% of patients in the form of glycuroconjugated metabolites, primarily 3 a, 5 ß–pregnanediol ( pregnandiol ). The glucuronide and sulfate conjugates of pregnanediol and pregnanolone are excreted in the urine and bile. Progesterone metabolites, excreted in the bile, may undergo enterohepatic recycling or may be found excreted in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Absorption half-life is approximately 25-50 hours and an elimination half-life of 5-20 minutes (progesterone gel). Progesterone, administered orally, has a short serum half-life (approximately 5 minutes). It is rapidly metabolized to 17-hydroxyprogesterone during its first pass through the liver. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance 1367 ± 348 (50mg of progesterone administered by vaginal insert once daily). 106 ± 15 L/h (50mg/mL IM injection once daily). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Intraperitoneal LD50 (rat): 327 mg/kg. Use in pregnancy Only forms of progesterone that are indicated on product labeling for pregnancy should be used. Some forms of progesterone should not be used in pregnancy,. Refer to individual product monographs for information regarding use in pregnancy. Many studies have found no effects on fetal development associated with long-term use of contraceptive doses of oral progestins. Studies of infant growth and development that have been conducted have not demonstrated significant adverse effects, however, these studies are few in number. It is therefore advisable to rule out suspected pregnancy before starting any hormonal contraceptive. Effects on fertility Progesterone at high doses is an antifertility drug and high doses would be expected to impair fertility until cessation. The progesterone contraceptive should not be used during pregnancy. Carcinogenicity Progesterone has been shown to induce or promote the formation of ovarian, uterine, mammary, and genital tract tumors in animals. The clinical relevance of these findings is unknown. Certain epidemiological studies of patients using oral contraceptives have reported an increased relative risk of developing breast cancer, especially at a younger age and associated with a longer duration of use. These studies have mainly involved combined oral contraceptives, and therefore, it is unknown whether this risk is attributable to progestins, estrogens, or a combination of both. At this time, there is insufficient data to determine whether the use of progestin-only contraceptives increases the risk in a similar way to combined contraceptives. A meta-analysis of 54 studies showed a small increase in the frequency of breast cancer diagnosis for women who were currently using combined oral contraceptives, or had used them within the past 10 years. There was no increase in the frequency of having breast cancer diagnosed ten or more years after cessation of hormone use. Women with breast cancer should not use oral contraceptives, as there is no sufficient data to fully establish or negate the risk of cancer with hormonal contraceptive use. Use in breastfeeding Progesterone has been detected in the milk of nursing mothers,. No adverse effects, in general, have been found on breastfeeding ability or on the health, growth, or development of the growing infant. Despite this, isolated post-marketing cases of decreased milk production have been reported. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bijuva, Crinone, Endometrin, Prochieve, Prometrium •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-Progesterone 17alpha-Progesterone Agolutin Akrolutin Corpus Luteum Hormone Gelbkörperhormon Luteohormone Lutogynon Progesteron Progesterona Progestérone Progesterone Progesteronum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Progesterone is a hormone used for a variety of functions, including contraception, control of abnormal uterine bleeding, maintenance of pregnancy, and prevention of endometrial hyperplasia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Progesterone interact? Information: •Drug A: Abatacept •Drug B: Progesterone •Severity: MODERATE •Description: The metabolism of Progesterone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Gelatinized capsules The gelatinized capsules are indicated for use in the prevention of endometrial hyperplasia in non-hysterectomized postmenopausal women who are receiving conjugated estrogens tablets. They are also indicated for use in secondary amenorrhea. Vaginal gel Progesterone gel (8%) is indicated as progesterone supplementation or replacement as part of an Assisted Reproductive Technology (“ART”) treatment for infertile women with progesterone deficiency. The lower concentration progesterone gel (4%) is used in the treatment of secondary amenorrhea, with the use of the 8% concentration if there is no therapeutic response to the 4% gel. Vaginal insert This form is indicated to support embryo implantation and early pregnancy by supplementation of corpus luteal function as part of an Assisted Reproductive Technology (ART) treatment program for infertile women. Injection (intramuscular) This drug is indicated in amenorrhea and abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as submucous fibroids or uterine cancer. Tablets, contraceptive The tablet form of progesterone in contraceptive formulations is indicated for the prevention of pregnancy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Progesterone, depending on concentration and dosage form, and timing of exposure may have several pharmacodynamic effects. These actions, according, to various preparations, are listed below: General effects Progesterone is the main hormone of the corpus luteum and the placenta. It acts on the uterus by changing the proliferative phase to the secretory phase of the endometrium (inner mucous lining of the uterus). This hormone, stimulated by a hormone called luteinizing hormone (LH) is the main hormone during the secretory phase to prepare the corpus luteum and the endometrium for implantation of a fertilized ovum. As the luteal phase concludes, the progesterone hormone sends negative feedback to the anterior pituitary gland in the brain to decrease FSH (follicle stimulating hormone) and LH (luteinizing hormone) levels. This prevents ovulation and maturation of oocytes (immature egg cells). The endometrium then prepares for pregnancy by increasing its vascularity (blood vessels) and stimulating mucous secretion. This process occurs by progesterone stimulating the endometrium to decrease endometrial proliferation, leading to a decreased uterine lining thickness, developing more complex uterine glands, collecting energy in the form of glycogen, and providing more uterine blood vessel surface area suitable for supporting a growing embryo. As opposed to cervical mucous changes observed during the proliferative phase and ovulation, progesterone decreases and thickens the cervical mucus, rendering it less elastic. This change occurs because the fertilization time period has passed, and a specific consistency of mucous amenable to sperm entry is no longer required. Gelatinized capsules Progesterone capsules are an oral dosage form of micronized progesterone which, chemically identical to progesterone of ovarian origin. Progesterone capsules have all the properties of endogenous progesterone with induction of a secretory phase endometrium with gestagenic, antiestrogenic, slightly antiandrogenic and anti-aldosterone effects. Progesterone opposes the effects of estrogen on the uterus, and is beneficial in women with unopposed estrogen exposure, which carries an increased risk of malignancy. Vaginal gel and vaginal insert The gel preparation mimics the effects of naturally occurring progesterone. In the presence of adequate levels of estrogen, progesterone converts a proliferative endometrium into secretory endometrium. This means that the endometrium changes from a growing and thickening stage into a subsequent preparation stage for pregnancy, which involves further preparatory changes. Progesterone is necessary for the development of decidual tissue (specialized tissue amenable to supporting a possible pregnancy). Progesterone is required to increase endometrial receptivity for the implantation of a fertilized embryo. Once an embryo is implanted, progesterone helps to maintain the pregnancy. Injection (intramuscular) Intramuscularly injected progesterone increases serum progesterone and aids in the prevention of endometrial tissue overgrowth due to unopposed estrogen (which leads to abnormal uterine bleeding and sometimes uterine cancer),. In the absence or deficiency of progesterone, the endometrium continually proliferates, eventually outgrowing its limited blood supply, shedding incompletely, and leading to abnormal and/or profuse bleeding as well as malignancy. Tablets, contraceptive Progesterone-only contraceptive tablets prevent conception by suppressing ovulation in about half of users, causing a thickening of cervical mucus to inhibit sperm movement, lowering the midcycle LH and FSH hormone peaks, slowing the movement of the ovum through the fallopian tubes, and causing secretory changes in the endometrium as described above. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Progesterone binds and activates its nuclear receptor, PR, which plays an important part in the signaling of stimuli that maintain the endometrium during its preparation for pregnancy. Progesterone receptor (PR) is a member of the nuclear/steroid hormone receptor (SHR) family of ligand-dependent transcription factors that is expressed primarily in female reproductive tissue as well as the central nervous system. As a result of its binding its associated steroid hormone, progesterone, the progesterone receptor (PR) modulates the expression of genes that regulate the development, differentiation, and proliferation of target tissues. In humans, PR is found to be highly expressed in the stromal (connective tissue) cells during the secretory phase and during pregnancy. Progesterone may prevent pregnancy by changing the consistency of cervical mucus to be unfavorable for sperm penetration, and by inhibiting follicle-stimulating hormone (FSH), which normally causes ovulation. With perfect use, the first-year failure rate for progestin-only oral contraceptives is approximately 0.5%. The typical failure rate, however, is estimated to be approximately 5%, due to late or missed pills. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral micronized capsules Following oral administration of progesterone in the micronized soft-gelatin capsule formulation, peak serum concentration was achieved in the first 3 hours. The absolute bioavailability of micronized progesterone is unknown at this time. In postmenopausal women, serum progesterone concentration increased in a dose-proportional and linear fashion after multiple doses of progesterone capsules, ranging from 100 mg/day to 300 mg/day. IM administration After intramuscular (IM) administration of 10 mg of progesterone in oil, the maximum plasma concentrations were achieved in about 8 hours post-injection and plasma concentrations stayed above baseline for approximately 24 hours post-injection. Injections of 10, 25, and 50 mg lead to geometric mean values for maximum plasma concentration (CMAX) of 7, 28, and 50 ng/mL, respectively. Progesterone administered by the intramuscular (IM) route avoids significant first-pass hepatic metabolism. As a result, endometrial tissue concentrations of progesterone achieved with IM administration are higher when compared with oral administration. Despite this, the highest concentrations of progesterone in endometrial tissue are reached with vaginal administration. Note on oral contraceptive tablet absorption Serum progestin levels peak about 2 hours after oral administration of progesterone-only contraceptive tablets, followed by rapid distribution and elimination. By 24 hours after drug administration, serum levels remain near the baseline, making efficacy dependent upon strict adherence to the dosing schedule. Large variations in serum progesterone levels occur among individuals. Progestin-only administration leads to lower steady-state serum progestin levels and a shorter elimination half-life than concurrent administration with estrogens. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): When administered vaginally, progesterone is well absorbed by uterine endometrial tissue, and a small percentage is distributed into the systemic circulation. The amount of progesterone in the systemic circulation appears to be of minimal importance, especially when implantation, pregnancy, and live birth outcomes appear similar for intramuscular and vaginal administration of progesterone. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96%-99% bound to serum proteins, primarily to serum albumin (50%-54%) and transcortin (43%-48%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Progesterone is mainly metabolized by the liver. After oral administration, the major plasma metabolites found are 20 a hydroxy-Δ4 a-prenolone and 5 a-dihydroprogesterone. Some progesterone metabolites are found excreted in the bile and these metabolites may be deconjugated and subsequently metabolized in the gut by reduction, dehydroxylation, and epimerization. The major plasma and urinary metabolites are comparable to those found during the physiological progesterone secretion of the corpus luteum. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Progesterone metabolites are excreted mainly by the kidneys. Urinary elimination is observed for 95% of patients in the form of glycuroconjugated metabolites, primarily 3 a, 5 ß–pregnanediol ( pregnandiol ). The glucuronide and sulfate conjugates of pregnanediol and pregnanolone are excreted in the urine and bile. Progesterone metabolites, excreted in the bile, may undergo enterohepatic recycling or may be found excreted in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Absorption half-life is approximately 25-50 hours and an elimination half-life of 5-20 minutes (progesterone gel). Progesterone, administered orally, has a short serum half-life (approximately 5 minutes). It is rapidly metabolized to 17-hydroxyprogesterone during its first pass through the liver. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance 1367 ± 348 (50mg of progesterone administered by vaginal insert once daily). 106 ± 15 L/h (50mg/mL IM injection once daily). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Intraperitoneal LD50 (rat): 327 mg/kg. Use in pregnancy Only forms of progesterone that are indicated on product labeling for pregnancy should be used. Some forms of progesterone should not be used in pregnancy,. Refer to individual product monographs for information regarding use in pregnancy. Many studies have found no effects on fetal development associated with long-term use of contraceptive doses of oral progestins. Studies of infant growth and development that have been conducted have not demonstrated significant adverse effects, however, these studies are few in number. It is therefore advisable to rule out suspected pregnancy before starting any hormonal contraceptive. Effects on fertility Progesterone at high doses is an antifertility drug and high doses would be expected to impair fertility until cessation. The progesterone contraceptive should not be used during pregnancy. Carcinogenicity Progesterone has been shown to induce or promote the formation of ovarian, uterine, mammary, and genital tract tumors in animals. The clinical relevance of these findings is unknown. Certain epidemiological studies of patients using oral contraceptives have reported an increased relative risk of developing breast cancer, especially at a younger age and associated with a longer duration of use. These studies have mainly involved combined oral contraceptives, and therefore, it is unknown whether this risk is attributable to progestins, estrogens, or a combination of both. At this time, there is insufficient data to determine whether the use of progestin-only contraceptives increases the risk in a similar way to combined contraceptives. A meta-analysis of 54 studies showed a small increase in the frequency of breast cancer diagnosis for women who were currently using combined oral contraceptives, or had used them within the past 10 years. There was no increase in the frequency of having breast cancer diagnosed ten or more years after cessation of hormone use. Women with breast cancer should not use oral contraceptives, as there is no sufficient data to fully establish or negate the risk of cancer with hormonal contraceptive use. Use in breastfeeding Progesterone has been detected in the milk of nursing mothers,. No adverse effects, in general, have been found on breastfeeding ability or on the health, growth, or development of the growing infant. Despite this, isolated post-marketing cases of decreased milk production have been reported. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bijuva, Crinone, Endometrin, Prochieve, Prometrium •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-Progesterone 17alpha-Progesterone Agolutin Akrolutin Corpus Luteum Hormone Gelbkörperhormon Luteohormone Lutogynon Progesteron Progesterona Progestérone Progesterone Progesteronum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Progesterone is a hormone used for a variety of functions, including contraception, control of abnormal uterine bleeding, maintenance of pregnancy, and prevention of endometrial hyperplasia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Promazine interact?

•Drug A: Abatacept •Drug B: Promazine •Severity: MODERATE •Description: The metabolism of Promazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used as an adjunct for short term treatment of moderate and severe psychomotor agitation. Also used to treat agitation or restlessness in the elderly. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Promazine belongs to a group of medications known as the phenothiazine antipsychotics. It acts by blocking a variety of receptors in the brain, particularly dopamine receptors. Dopamine is involved in transmitting signals between brain cells. When there is an excess amount of dopamine in the brain it causes over-stimulation of dopamine receptors. These receptors normally act to modify behaviour and over-stimulation may result in psychotic illness. Promazine hydrochloride blocks these receptors and stops them becoming over-stimulated, thereby helping to control psychotic illness. Promazine has weak extrapyramidal and autonomic side effects which lead to its use in the elderly, for restless or psychotic patients. Its anti-psychotic effect is also weaker and it is not useful in general psychiatry. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Promazine is an antagonist at types 1, 2, and 4 dopamine receptors, 5-HT receptor types 2A and 2C, muscarinic receptors 1 through 5, alpha(1)-receptors, and histamine H1-receptors. Promazine's antipsychotic effect is due to antagonism at dopamine and serotonin type 2 receptors, with greater activity at serotonin 5-HT2 receptors than at dopamine type-2 receptors. This may explain the lack of extrapyramidal effects. Promazine does not appear to block dopamine within the tubero-infundibular tract, explaining the lower incidence of hyperprolactinemia than with typical antipsychotic agents or risperidone. Antagonism at muscarinic receptors, H1-receptors, and alpha(1)-receptors also occurs with promazine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption may be erratic and peak plasma concentrations show large interindividual differences. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 94% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, primarily to N-desmethylpromazine and promazine sulfoxide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include: extrapyramidal symptoms, drowsiness, weight gain, dry mouth, constipation, endocrine effects (such as gynaecomastia and menstrual disturbance), sensitivity to sunlight and haemolytic anaemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Promazin Promazina Promazine Promazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Promazine is a phenothiazine used to manage schizophrenia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Promazine interact? Information: •Drug A: Abatacept •Drug B: Promazine •Severity: MODERATE •Description: The metabolism of Promazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used as an adjunct for short term treatment of moderate and severe psychomotor agitation. Also used to treat agitation or restlessness in the elderly. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Promazine belongs to a group of medications known as the phenothiazine antipsychotics. It acts by blocking a variety of receptors in the brain, particularly dopamine receptors. Dopamine is involved in transmitting signals between brain cells. When there is an excess amount of dopamine in the brain it causes over-stimulation of dopamine receptors. These receptors normally act to modify behaviour and over-stimulation may result in psychotic illness. Promazine hydrochloride blocks these receptors and stops them becoming over-stimulated, thereby helping to control psychotic illness. Promazine has weak extrapyramidal and autonomic side effects which lead to its use in the elderly, for restless or psychotic patients. Its anti-psychotic effect is also weaker and it is not useful in general psychiatry. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Promazine is an antagonist at types 1, 2, and 4 dopamine receptors, 5-HT receptor types 2A and 2C, muscarinic receptors 1 through 5, alpha(1)-receptors, and histamine H1-receptors. Promazine's antipsychotic effect is due to antagonism at dopamine and serotonin type 2 receptors, with greater activity at serotonin 5-HT2 receptors than at dopamine type-2 receptors. This may explain the lack of extrapyramidal effects. Promazine does not appear to block dopamine within the tubero-infundibular tract, explaining the lower incidence of hyperprolactinemia than with typical antipsychotic agents or risperidone. Antagonism at muscarinic receptors, H1-receptors, and alpha(1)-receptors also occurs with promazine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption may be erratic and peak plasma concentrations show large interindividual differences. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 94% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, primarily to N-desmethylpromazine and promazine sulfoxide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include: extrapyramidal symptoms, drowsiness, weight gain, dry mouth, constipation, endocrine effects (such as gynaecomastia and menstrual disturbance), sensitivity to sunlight and haemolytic anaemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Promazin Promazina Promazine Promazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Promazine is a phenothiazine used to manage schizophrenia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Promethazine interact?

•Drug A: Abatacept •Drug B: Promethazine •Severity: MODERATE •Description: The metabolism of Promethazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Promethazine tablets and suppositories are indicated to treat rhinitis, allergic conjunctivitis, allergic reactions to blood or plasma, dermographism, anaphylactic reactions, sedation, nausea, vomiting, pain, motion sickness, and allergic skin reactions. Promethazine cough syrup with phenylephrine and codeine is indicated to relieve cough and upper respiratory symptoms, and nasal congestion associated with allergy or the common cold. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Promethazine is is a histamine H1 antagonist that can be used for it's ability to induce sedation, reduce pain, and treat allergic reactions. Promethazine's effects generally last 4-6h but can last up to 12h. Patients should be counselled regarding CNS and respiratory depression, reduce seizure threshold, and bone marrow depression. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Promethazine is a an antagonist of histamine H1, post-synaptic mesolimbic dopamine, alpha adrenergic, muscarinic, and NMDA receptors. The antihistamine action is used to treat allergic reactions. Antagonism of muscarinic and NMDA receptors contribute to its use as a sleep aid, as well as for anxiety and tension. Antagonism of histamine H1, muscarinic, and dopamine receptors in the medullary vomiting center make promethazine useful in the treatment of nausea and vomiting. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 25mg dose of intramuscular promethazine reaches a C max of 22ng/mL. Intravenous promethazine reaches a C max of 10.0ng/mL, with a T max of 4-10h, and an AUC of 14,466ng*h/mL. Oral promethazine is only 25% bioavailable due to first pass metabolism. Oral promethazine reaches a C max of 2.4-18.0ng/mL, with a T max of 1.5-3h, and an AUC of 11,511ng*h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of promethazine is approximately 970L or 30L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Promethazine is 93% protein bound in serum, mostly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Promethazine is predominantly metabolized to promethazine sulfoxide, and minorly to desmethylpromethazine and a hydroxy metabolite. Hydroxylation of promethazine is predominantly mediated by CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): An intravenous dose of promethazine is 0.64% eliminated in the urine as the unchanged parent drug, 0.02-2.02% in the urine as desmethylpromethazine, 10% in the urine as promethazine sulfoxide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life of promethazine is approximately 12-15h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The intravenous clearance of promethazine is approximately 1.14L/min. The renal clearance of promethazine is 5.9mL/min and the renal clearance of promethazine sulfoxide is 90.4mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The intraperitoneal LD 50 in rats is 170mg/kg and in mice is 160mg/kg. The subcutaneous LD 50 in rats is 400mg/kg and in mice is 240mg/kg. The oral LD 50 in mice is 255mg/kg. Patients experiencing an overdose of promethazine may present with mild central nervous system and cardiovascular depression, hypotension, respiratory depression, unconciousness, hyperreflexia, hypertonia, ataxia, athetosis, extensor-plantar reflexes, convulsions, dry mouth, flushing, gastrointestinal symptoms, and fixed, dilated pupils. Treat overdoses with symptomatic and supportive treatment, which may include activated charcoal, sodium sulfate, magnesium sulfate, controlled ventilation, diazepam, intravenous fluids, vasopressors, norepinephrine, phenylephrine, anticholinergic antiparkinsonian agents, diphenhydramine, barbiturates, or oxygen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Phenadoz, Phenergan, Promethazine DM, Promethegan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Proazamine Prometazina Promethazine Promethazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Promethazine is a first-generation antihistamine used for the treatment of allergic conditions, nausea and vomiting, and motion sickness.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Promethazine interact? Information: •Drug A: Abatacept •Drug B: Promethazine •Severity: MODERATE •Description: The metabolism of Promethazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Promethazine tablets and suppositories are indicated to treat rhinitis, allergic conjunctivitis, allergic reactions to blood or plasma, dermographism, anaphylactic reactions, sedation, nausea, vomiting, pain, motion sickness, and allergic skin reactions. Promethazine cough syrup with phenylephrine and codeine is indicated to relieve cough and upper respiratory symptoms, and nasal congestion associated with allergy or the common cold. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Promethazine is is a histamine H1 antagonist that can be used for it's ability to induce sedation, reduce pain, and treat allergic reactions. Promethazine's effects generally last 4-6h but can last up to 12h. Patients should be counselled regarding CNS and respiratory depression, reduce seizure threshold, and bone marrow depression. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Promethazine is a an antagonist of histamine H1, post-synaptic mesolimbic dopamine, alpha adrenergic, muscarinic, and NMDA receptors. The antihistamine action is used to treat allergic reactions. Antagonism of muscarinic and NMDA receptors contribute to its use as a sleep aid, as well as for anxiety and tension. Antagonism of histamine H1, muscarinic, and dopamine receptors in the medullary vomiting center make promethazine useful in the treatment of nausea and vomiting. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 25mg dose of intramuscular promethazine reaches a C max of 22ng/mL. Intravenous promethazine reaches a C max of 10.0ng/mL, with a T max of 4-10h, and an AUC of 14,466ng*h/mL. Oral promethazine is only 25% bioavailable due to first pass metabolism. Oral promethazine reaches a C max of 2.4-18.0ng/mL, with a T max of 1.5-3h, and an AUC of 11,511ng*h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of promethazine is approximately 970L or 30L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Promethazine is 93% protein bound in serum, mostly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Promethazine is predominantly metabolized to promethazine sulfoxide, and minorly to desmethylpromethazine and a hydroxy metabolite. Hydroxylation of promethazine is predominantly mediated by CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): An intravenous dose of promethazine is 0.64% eliminated in the urine as the unchanged parent drug, 0.02-2.02% in the urine as desmethylpromethazine, 10% in the urine as promethazine sulfoxide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life of promethazine is approximately 12-15h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The intravenous clearance of promethazine is approximately 1.14L/min. The renal clearance of promethazine is 5.9mL/min and the renal clearance of promethazine sulfoxide is 90.4mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The intraperitoneal LD 50 in rats is 170mg/kg and in mice is 160mg/kg. The subcutaneous LD 50 in rats is 400mg/kg and in mice is 240mg/kg. The oral LD 50 in mice is 255mg/kg. Patients experiencing an overdose of promethazine may present with mild central nervous system and cardiovascular depression, hypotension, respiratory depression, unconciousness, hyperreflexia, hypertonia, ataxia, athetosis, extensor-plantar reflexes, convulsions, dry mouth, flushing, gastrointestinal symptoms, and fixed, dilated pupils. Treat overdoses with symptomatic and supportive treatment, which may include activated charcoal, sodium sulfate, magnesium sulfate, controlled ventilation, diazepam, intravenous fluids, vasopressors, norepinephrine, phenylephrine, anticholinergic antiparkinsonian agents, diphenhydramine, barbiturates, or oxygen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Phenadoz, Phenergan, Promethazine DM, Promethegan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Proazamine Prometazina Promethazine Promethazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Promethazine is a first-generation antihistamine used for the treatment of allergic conditions, nausea and vomiting, and motion sickness. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Propafenone interact?

•Drug A: Abatacept •Drug B: Propafenone •Severity: MODERATE •Description: The metabolism of Propafenone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used to prolong the time to recurrence of paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms in patients without structural heart disease. Also used for the treatment of life-threatening documented ventricular arrhythmias, such as sustained ventricular tachycardia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propafenone is a Class 1C antiarrhythmic drug with local anesthetic effects, and a direct stabilizing action on myocardial membranes. It is used in the treatment of atrial and ventricular arrhythmias. It acts by inhibiting sodium channels to restrict the entry of sodium into cardiac cells resulting in reduced excitation. Propafenone has local anesthetic activity approximately equal to procaine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The electrophysiological effect of propafenone manifests itself in a reduction of upstroke velocity (Phase 0) of the monophasic action potential. In Purkinje fibers, and to a lesser extent myocardial fibers, propafenone reduces the fast inward current carried by sodium ions, which is responsible for the drugs antiarrhythmic actions. Diastolic excitability threshold is increased and effective refractory period prolonged. Propafenone reduces spontaneous automaticity and depresses triggered activity. At very high concentrations in vitro, propafenone can inhibit the slow inward current carried by calcium but this calcium antagonist effect probably does not contribute to antiarrhythmic efficacy. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Nearly completely absorbed following oral administration (90%). Systemic bioavailability ranges from 5 to 50%, due to significant first-pass metabolism. This wide range in systemic bioavailability is related to two factors: presence of food (food increases bioavailability) and dosage (bioavailability is 3.4% for a 150-mg tablet compared to 10.6% for a 300-mg tablet). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 252 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized primarily in the liver where it is rapidly and extensively metabolized to two active metabolites, 5-hydroxypropafenone and N-depropylpropafenone. These metabolites have antiarrhythmic activity comparable to propafenone but are present in concentrations less than 25% of propafenone concentrations. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of propafenone metabolites are excreted in the urine following administration of immediate release tablets. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2-10 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of propafenone overdose (usually most severe within the first 3 hours) may include convulsions (rarely), heartbeat irregularities, low blood pressure, and sleepiness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rythmol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Propafenona Propafenone Propafenonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propafenone is a Class 1C antiarrhythmic agent used in the management of paroxysmal atrial fibrillation/flutter and ventricular arrhythmias.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Propafenone interact? Information: •Drug A: Abatacept •Drug B: Propafenone •Severity: MODERATE •Description: The metabolism of Propafenone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used to prolong the time to recurrence of paroxysmal atrial fibrillation/flutter (PAF) associated with disabling symptoms in patients without structural heart disease. Also used for the treatment of life-threatening documented ventricular arrhythmias, such as sustained ventricular tachycardia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propafenone is a Class 1C antiarrhythmic drug with local anesthetic effects, and a direct stabilizing action on myocardial membranes. It is used in the treatment of atrial and ventricular arrhythmias. It acts by inhibiting sodium channels to restrict the entry of sodium into cardiac cells resulting in reduced excitation. Propafenone has local anesthetic activity approximately equal to procaine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The electrophysiological effect of propafenone manifests itself in a reduction of upstroke velocity (Phase 0) of the monophasic action potential. In Purkinje fibers, and to a lesser extent myocardial fibers, propafenone reduces the fast inward current carried by sodium ions, which is responsible for the drugs antiarrhythmic actions. Diastolic excitability threshold is increased and effective refractory period prolonged. Propafenone reduces spontaneous automaticity and depresses triggered activity. At very high concentrations in vitro, propafenone can inhibit the slow inward current carried by calcium but this calcium antagonist effect probably does not contribute to antiarrhythmic efficacy. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Nearly completely absorbed following oral administration (90%). Systemic bioavailability ranges from 5 to 50%, due to significant first-pass metabolism. This wide range in systemic bioavailability is related to two factors: presence of food (food increases bioavailability) and dosage (bioavailability is 3.4% for a 150-mg tablet compared to 10.6% for a 300-mg tablet). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 252 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized primarily in the liver where it is rapidly and extensively metabolized to two active metabolites, 5-hydroxypropafenone and N-depropylpropafenone. These metabolites have antiarrhythmic activity comparable to propafenone but are present in concentrations less than 25% of propafenone concentrations. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of propafenone metabolites are excreted in the urine following administration of immediate release tablets. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2-10 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of propafenone overdose (usually most severe within the first 3 hours) may include convulsions (rarely), heartbeat irregularities, low blood pressure, and sleepiness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rythmol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Propafenona Propafenone Propafenonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propafenone is a Class 1C antiarrhythmic agent used in the management of paroxysmal atrial fibrillation/flutter and ventricular arrhythmias. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Propofol interact?

•Drug A: Abatacept •Drug B: Propofol •Severity: MODERATE •Description: The metabolism of Propofol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used for induction and/or maintenance of anaesthesia and for management of refractory status epilepticus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propofol is a sedative-hypnotic agent for use in the induction and maintenance of anesthesia or sedation. Intravenous injection of a therapeutic dose of propofol produces hypnosis rapidly with minimal excitation, usually within 40 seconds from the start of an injection (the time for one arm-brain circulation). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The action of propofol involves a positive modulation of the inhibitory function of the neurotransmitter gama-aminobutyric acid (GABA) through GABA-A receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapid - time to onset of unconsciousness is 15-30 seconds, due to rapid distribution from plasma to the CNS. Distribution is so rapid that peak plasma concentrations cannot be readily measured. Duration of action is 5-10 minutes. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 60 L/kg [healthy adults] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95 to 99%, primarily to serum albumin and hemoglobin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatically metabolized mainly by glucuronidation at the C1-hydroxyl. Hydroxylation of the benzene ring to 4-hydroxypropofol may also occur via CYP2B6 and 2C9 with subsequent conjugation to sulfuric and/or glucuronic acid. Hydroxypropofol has approximately 1/3 of hypnotic activity of propofol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): It is chiefly eliminated by hepatic conjugation to inactive metabolites which are excreted by the kidney. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Initial distribution phase t 1/2α =1.8-9.5 minutes. Second redistirubtion phase t 1/2β =21-70 minutes. Terminal elimination phase t 1/2γ =1.5-31 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 23 - 50 mL/kg/min 1.6 - 3.4 L/min [70 Kg adults] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage may increase pharmacologic and adverse effects or cause death. IV LD 50 =53 mg/kg (mice), 42 mg/kg (rats). Oral LD 50 (as a solution in soybean oil)=1230 mg/kg (mice), 600 mg/kg (rats) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diprivan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Propofol Propofolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propofol is a medication used in general anesthesia and for sedation.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Propofol interact? Information: •Drug A: Abatacept •Drug B: Propofol •Severity: MODERATE •Description: The metabolism of Propofol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used for induction and/or maintenance of anaesthesia and for management of refractory status epilepticus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propofol is a sedative-hypnotic agent for use in the induction and maintenance of anesthesia or sedation. Intravenous injection of a therapeutic dose of propofol produces hypnosis rapidly with minimal excitation, usually within 40 seconds from the start of an injection (the time for one arm-brain circulation). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The action of propofol involves a positive modulation of the inhibitory function of the neurotransmitter gama-aminobutyric acid (GABA) through GABA-A receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapid - time to onset of unconsciousness is 15-30 seconds, due to rapid distribution from plasma to the CNS. Distribution is so rapid that peak plasma concentrations cannot be readily measured. Duration of action is 5-10 minutes. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 60 L/kg [healthy adults] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95 to 99%, primarily to serum albumin and hemoglobin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatically metabolized mainly by glucuronidation at the C1-hydroxyl. Hydroxylation of the benzene ring to 4-hydroxypropofol may also occur via CYP2B6 and 2C9 with subsequent conjugation to sulfuric and/or glucuronic acid. Hydroxypropofol has approximately 1/3 of hypnotic activity of propofol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): It is chiefly eliminated by hepatic conjugation to inactive metabolites which are excreted by the kidney. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Initial distribution phase t 1/2α =1.8-9.5 minutes. Second redistirubtion phase t 1/2β =21-70 minutes. Terminal elimination phase t 1/2γ =1.5-31 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 23 - 50 mL/kg/min 1.6 - 3.4 L/min [70 Kg adults] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage may increase pharmacologic and adverse effects or cause death. IV LD 50 =53 mg/kg (mice), 42 mg/kg (rats). Oral LD 50 (as a solution in soybean oil)=1230 mg/kg (mice), 600 mg/kg (rats) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diprivan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Propofol Propofolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propofol is a medication used in general anesthesia and for sedation. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Propranolol interact?

•Drug A: Abatacept •Drug B: Propranolol •Severity: MODERATE •Description: The metabolism of Propranolol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Propranolol is indicated to treat hypertension. Propranolol is also indicated to treat angina pectoris due to coronary atherosclerosis, atrial fibrillation, myocardial infarction, migraine, essential tremor, hypertrophic subaortic stenosis, pheochromocytoma, and proliferating infantile hemangioma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propranolol is a beta-adrenergic receptor antagonist used to treat hypertension. Propranolol has a long duration of action as it is given once or twice daily depending on the indication. When patients abruptly stop taking propranolol, they may experience exacerbations of angina and myocardial infarctions. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propranolol is a nonselective β-adrenergic receptor antagonist. Blocking of these receptors leads to vasoconstriction, inhibition of angiogenic factors like vascular endothelial growth factor (VEGF) and basic growth factor of fibroblasts (bFGF), induction of apoptosis of endothelial cells, as well as down regulation of the renin-angiotensin-aldosterone system. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Patients taking doses of 40mg, 80mg, 160mg, and 320mg daily experienced C max values of 18±15ng/mL, 52±51ng/mL, 121±98ng/mL, and 245±110ng/mL respectively. Propranolol has a T max of approximately 2 hours, though this can range from 1 to 4 hours in fasting patients. Taking propranolol with food does not increase T max but does increase bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of propranolol is approximately 4L/kg or 320L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 90% of propranolol is protein bound in plasma. Other studies have reported ranges of 85-96%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Propranolol undergoes side chain oxidation to α-naphthoxylactic acid, ring oxidation to 4’-hydroxypropranolol, or glucuronidation to propranolol glucuronide. It can also be N-desisopropylated to become N-desisopropyl propranolol. 17% of a dose undergoes glucuronidation and 42% undergoes ring oxidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 91% of an oral dose of propranolol is recovered as 12 metabolites in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of propranolol is approximately 8 hours. The plasma half-life of propranolol is 3 to 6 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of propranolol is 2.7±0.03L/h/kg in infants <90 days and 3.3±0.35L/h/kg in infants >90 days. Propranolol clearance increases linearly with hepatic blood flow. Propranolol has a clearance in hypertensive adults of 810mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include hypotension, hypoglycemic seizure, restlessness, euphoria, insomnia. Patients with asthma may develop bronchospasm. In case of overdose, monitor vital signs, mental status, and blood glucose. Treat hypotension with intravenous fluids, bradycardia with atropine, and isoproterenol and aminophylline for bronchospasm. If patients do not respond to intravenous fluids, follow up with glucagon 50-150µg/kg intravenously, then 1-5mg/hour, followed by catecholamines. Dialysis will not be useful as propranolol is highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hemangeol, Hemangiol, Inderal, Innopran •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): beta-Propranolol Propanalol Propanolol Propranolol Propranololo Propranololum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propranolol is a non-selective beta adrenergic antagonist used to treat hypertension, angina, atrial fibrillation, myocardial infarction, migraine, essential tremor, hypertrophic subaortic stenosis, and pheochromocytoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Propranolol interact? Information: •Drug A: Abatacept •Drug B: Propranolol •Severity: MODERATE •Description: The metabolism of Propranolol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Propranolol is indicated to treat hypertension. Propranolol is also indicated to treat angina pectoris due to coronary atherosclerosis, atrial fibrillation, myocardial infarction, migraine, essential tremor, hypertrophic subaortic stenosis, pheochromocytoma, and proliferating infantile hemangioma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propranolol is a beta-adrenergic receptor antagonist used to treat hypertension. Propranolol has a long duration of action as it is given once or twice daily depending on the indication. When patients abruptly stop taking propranolol, they may experience exacerbations of angina and myocardial infarctions. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propranolol is a nonselective β-adrenergic receptor antagonist. Blocking of these receptors leads to vasoconstriction, inhibition of angiogenic factors like vascular endothelial growth factor (VEGF) and basic growth factor of fibroblasts (bFGF), induction of apoptosis of endothelial cells, as well as down regulation of the renin-angiotensin-aldosterone system. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Patients taking doses of 40mg, 80mg, 160mg, and 320mg daily experienced C max values of 18±15ng/mL, 52±51ng/mL, 121±98ng/mL, and 245±110ng/mL respectively. Propranolol has a T max of approximately 2 hours, though this can range from 1 to 4 hours in fasting patients. Taking propranolol with food does not increase T max but does increase bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of propranolol is approximately 4L/kg or 320L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 90% of propranolol is protein bound in plasma. Other studies have reported ranges of 85-96%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Propranolol undergoes side chain oxidation to α-naphthoxylactic acid, ring oxidation to 4’-hydroxypropranolol, or glucuronidation to propranolol glucuronide. It can also be N-desisopropylated to become N-desisopropyl propranolol. 17% of a dose undergoes glucuronidation and 42% undergoes ring oxidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 91% of an oral dose of propranolol is recovered as 12 metabolites in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of propranolol is approximately 8 hours. The plasma half-life of propranolol is 3 to 6 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of propranolol is 2.7±0.03L/h/kg in infants <90 days and 3.3±0.35L/h/kg in infants >90 days. Propranolol clearance increases linearly with hepatic blood flow. Propranolol has a clearance in hypertensive adults of 810mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include hypotension, hypoglycemic seizure, restlessness, euphoria, insomnia. Patients with asthma may develop bronchospasm. In case of overdose, monitor vital signs, mental status, and blood glucose. Treat hypotension with intravenous fluids, bradycardia with atropine, and isoproterenol and aminophylline for bronchospasm. If patients do not respond to intravenous fluids, follow up with glucagon 50-150µg/kg intravenously, then 1-5mg/hour, followed by catecholamines. Dialysis will not be useful as propranolol is highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hemangeol, Hemangiol, Inderal, Innopran •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): beta-Propranolol Propanalol Propanolol Propranolol Propranololo Propranololum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propranolol is a non-selective beta adrenergic antagonist used to treat hypertension, angina, atrial fibrillation, myocardial infarction, migraine, essential tremor, hypertrophic subaortic stenosis, and pheochromocytoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Propylthiouracil interact?

•Drug A: Abatacept •Drug B: Propylthiouracil •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Propylthiouracil is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used to manage hyperthyroidism which is due to an overactive thyroid gland (Grave's disease). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propylthiouracil is a thiourea antithyroid agent. Grave's disease is the most common cause of hyperthyroidism. It is an autoimmune disease where an individual's own antibodies attach to thyroid stimulating hormone receptors within cells of the thyroid gland and then trigger overproduction of thyroid hormone. The two thyroid hormones manufactured by the thyroid gland, thyroxine (T4) and triiodothyronine (T3), are formed by combining iodine and a protein called thyroglobulin with the assistance of an enzyme called peroxidase. PTU inhibits iodine and peroxidase from their normal interactions with thyroglobulin to form T4 and T3. This action decreases thyroid hormone production. PTU also interferes with the conversion of T4 to T3, and, since T3 is more potent than T4, this also reduces the activity of thyroid hormones. The actions and use of propylthiouracil are similar to those of methimazole. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propylthiouracil binds to thyroid peroxidase and thereby inhibits the conversion of iodide to iodine. Thyroid peroxidase normally converts iodide to iodine (via hydrogen peroxide as a cofactor) and also catalyzes the incorporation of the resulting iodide molecule onto both the 3 and/or 5 positions of the phenol rings of tyrosines found in thyroglobulin. Thyroglobulin is degraded to produce thyroxine (T4) and tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. Therefore propylthiouracil effectively inhibits the production of new thyroid hormones. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 82% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Propylthiouracil is readily absorbed and is extensively metabolized. Approximately 35% of the drug is excreted in the urine, in intact and conjugated forms, within 24 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, rat: LD 50 = 1250 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 6-Propylthiouracil Propiltiouracilo Propylthiouracil Propylthiouracile Propylthiouracilum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propylthiouracil is a thiourea antithyroid agent used to treat hyperthyroidism.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Propylthiouracil interact? Information: •Drug A: Abatacept •Drug B: Propylthiouracil •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Propylthiouracil is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used to manage hyperthyroidism which is due to an overactive thyroid gland (Grave's disease). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propylthiouracil is a thiourea antithyroid agent. Grave's disease is the most common cause of hyperthyroidism. It is an autoimmune disease where an individual's own antibodies attach to thyroid stimulating hormone receptors within cells of the thyroid gland and then trigger overproduction of thyroid hormone. The two thyroid hormones manufactured by the thyroid gland, thyroxine (T4) and triiodothyronine (T3), are formed by combining iodine and a protein called thyroglobulin with the assistance of an enzyme called peroxidase. PTU inhibits iodine and peroxidase from their normal interactions with thyroglobulin to form T4 and T3. This action decreases thyroid hormone production. PTU also interferes with the conversion of T4 to T3, and, since T3 is more potent than T4, this also reduces the activity of thyroid hormones. The actions and use of propylthiouracil are similar to those of methimazole. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propylthiouracil binds to thyroid peroxidase and thereby inhibits the conversion of iodide to iodine. Thyroid peroxidase normally converts iodide to iodine (via hydrogen peroxide as a cofactor) and also catalyzes the incorporation of the resulting iodide molecule onto both the 3 and/or 5 positions of the phenol rings of tyrosines found in thyroglobulin. Thyroglobulin is degraded to produce thyroxine (T4) and tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. Therefore propylthiouracil effectively inhibits the production of new thyroid hormones. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 82% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Propylthiouracil is readily absorbed and is extensively metabolized. Approximately 35% of the drug is excreted in the urine, in intact and conjugated forms, within 24 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, rat: LD 50 = 1250 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 6-Propylthiouracil Propiltiouracilo Propylthiouracil Propylthiouracile Propylthiouracilum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Propylthiouracil is a thiourea antithyroid agent used to treat hyperthyroidism. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Quetiapine interact?

•Drug A: Abatacept •Drug B: Quetiapine •Severity: MODERATE •Description: The metabolism of Quetiapine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quetiapine is used in the symptomatic treatment of schizophrenia. In addition, it may be used for the management of acute manic or mixed episodes in patients with bipolar I disorder, as a monotherapy or combined with other drugs. It may be used to manage depressive episodes in bipolar disorder. In addition to the above indications, quetiapine is used in combination with antidepressant drugs for the treatment of major depression. Some off-label uses for this drug include the management of post-traumatic stress disorder (PTSD), generalized anxiety disorder, and psychosis associated with Parkinson's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quetiapine improves the positive and negative symptoms of schizophrenia and major depression by acting on various neurotransmitter receptors, such as the serotonin and dopamine receptors. In bipolar disorder, it improves both depressive and manic symptoms. A note on suicidality in young patients and administration in the elderly Quetiapine can cause suicidal thinking or behavior in children and adolescents and should not be given to children under 10 years of age. It is important to monitor for suicidality if this drug is given to younger patients. In addition, this drug is not indicated for the treatment of psychosis related to dementia due to an increased death rate in elderly patients taking this drug. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the mechanism of action of quetiapine is not fully understood, several proposed mechanisms exist. In schizophrenia, its actions could occur from the antagonism of dopamine type 2 (D2) and serotonin 2A (5HT2A) receptors. In bipolar depression and major depression, quetiapine's actions may be attributed to the binding of this drug or its metabolite to the norepinephrine transporter. Additional effects of quetiapine, including somnolence, orthostatic hypotension, and anticholinergic effects, may result from the antagonism of H1 receptors, adrenergic α1 receptors, and muscarinic M1 receptors, respectively. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Quetiapine is rapidly and well absorbed after administration of an oral dose. Steady-state is achieved within 48 hours Peak plasma concentrations are achieved within 1.5 hours. The bioavailability of a tablet is 100%. The steady-state Cmax of quetiapine in Han Chinese patients with schizophrenia after a 300 mg oral dose of the extended released formulation was approximately 467 ng/mL and the AUC at steady-state was 5094 ng·h/mL. Absorption of quetiapine is affected by food, with Cmax increased by 25% and AUC increased by 15%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Quetiapine distributes throughout body tissues. The apparent volume of distribution of this drug is about 10±4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of quetiapine is 83%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of quetiapine occurs mainly in the liver. Sulfoxidation and oxidation are the main metabolic pathways of this drug. According to in vitro studies, cytochrome P450 3A4 metabolizes quetiapine to an inactive sulfoxide metabolite and also participates in the metabolism of its active metabolite, N-desalkyl quetiapine. CYP2D6 also regulates the metabolism of quetiapine. In one study, three metabolites of N-desalkylquetiapine were identified. Two of the metabolites were identified as N-desalkylquetiapine sulfoxide and 7-hydroxy-N-desalkylquetiapine. CYP2D6 has been found to be responsible for metabolism of quetiapine to 7-hydroxy-N-desalkylquetiapine, a pharmacologically active metabolite. Individual differences in CYP2D6 metabolism may be present, which may affect the concentrations of the active metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After an oral dose of radiolabeled quetiapine, less than 1% of unchanged drug was detected in the urine, suggesting that quetiapine is heavily metabolized. About 73% of a dose was detected in the urine, and about 20% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The average terminal half-life of quetiapine is about 6-7 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of quetiapine healthy volunteers in the fasted state during a clinical study was 101.04±39.11 L/h. Elderly patients may require lower doses of quetiapine, as clearance in these patients may be reduced by up to 50%. Those with liver dysfunction may also require lower doses. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 if quetiapine in rats is 2000 mg/kg. Overdose information Some signs and symptoms of a quetiapine overdose include sedation, drowsiness, tachycardia, and hypotension. Clinical trials demonstrate that overdoses of up to 30 grams of quetiapine did not result in death. A lethal outcome was reported in a clinical trial after an overdose of 13.6 grams of quetiapine. In the case of an acute overdose, ensure to maintain an airway and provide adequate ventilation and oxygenation. Gastric lavage following intubation (if necessary) along with activated charcoal and a laxative may be considered. The possibility of obtundation, seizure or dystonic reaction of the head and neck following overdose may create a risk of aspiration with induced emesis. Cardiac monitoring should also take place. A note on QT-interval prolongation in an overdose Postmarketing reports reveal increases in the cardiac QT interval in cases of quetiapine overdose, concomitant illness, and in those taking drugs that increase QT interval or affect electrolyte levels. Note that disopyramide, procainamide, and quinidine may exert additive QT-prolonging effects when administered in patients who have overdosed with quetiapine, and should be avoided. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Seroquel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Quetiapina Quétiapine Quetiapine Quetiapinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quetiapine is an atypical antipsychotic agent used for the management of bipolar disorder, schizophrenia, and major depressive disorder.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Quetiapine interact? Information: •Drug A: Abatacept •Drug B: Quetiapine •Severity: MODERATE •Description: The metabolism of Quetiapine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quetiapine is used in the symptomatic treatment of schizophrenia. In addition, it may be used for the management of acute manic or mixed episodes in patients with bipolar I disorder, as a monotherapy or combined with other drugs. It may be used to manage depressive episodes in bipolar disorder. In addition to the above indications, quetiapine is used in combination with antidepressant drugs for the treatment of major depression. Some off-label uses for this drug include the management of post-traumatic stress disorder (PTSD), generalized anxiety disorder, and psychosis associated with Parkinson's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quetiapine improves the positive and negative symptoms of schizophrenia and major depression by acting on various neurotransmitter receptors, such as the serotonin and dopamine receptors. In bipolar disorder, it improves both depressive and manic symptoms. A note on suicidality in young patients and administration in the elderly Quetiapine can cause suicidal thinking or behavior in children and adolescents and should not be given to children under 10 years of age. It is important to monitor for suicidality if this drug is given to younger patients. In addition, this drug is not indicated for the treatment of psychosis related to dementia due to an increased death rate in elderly patients taking this drug. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the mechanism of action of quetiapine is not fully understood, several proposed mechanisms exist. In schizophrenia, its actions could occur from the antagonism of dopamine type 2 (D2) and serotonin 2A (5HT2A) receptors. In bipolar depression and major depression, quetiapine's actions may be attributed to the binding of this drug or its metabolite to the norepinephrine transporter. Additional effects of quetiapine, including somnolence, orthostatic hypotension, and anticholinergic effects, may result from the antagonism of H1 receptors, adrenergic α1 receptors, and muscarinic M1 receptors, respectively. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Quetiapine is rapidly and well absorbed after administration of an oral dose. Steady-state is achieved within 48 hours Peak plasma concentrations are achieved within 1.5 hours. The bioavailability of a tablet is 100%. The steady-state Cmax of quetiapine in Han Chinese patients with schizophrenia after a 300 mg oral dose of the extended released formulation was approximately 467 ng/mL and the AUC at steady-state was 5094 ng·h/mL. Absorption of quetiapine is affected by food, with Cmax increased by 25% and AUC increased by 15%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Quetiapine distributes throughout body tissues. The apparent volume of distribution of this drug is about 10±4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of quetiapine is 83%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of quetiapine occurs mainly in the liver. Sulfoxidation and oxidation are the main metabolic pathways of this drug. According to in vitro studies, cytochrome P450 3A4 metabolizes quetiapine to an inactive sulfoxide metabolite and also participates in the metabolism of its active metabolite, N-desalkyl quetiapine. CYP2D6 also regulates the metabolism of quetiapine. In one study, three metabolites of N-desalkylquetiapine were identified. Two of the metabolites were identified as N-desalkylquetiapine sulfoxide and 7-hydroxy-N-desalkylquetiapine. CYP2D6 has been found to be responsible for metabolism of quetiapine to 7-hydroxy-N-desalkylquetiapine, a pharmacologically active metabolite. Individual differences in CYP2D6 metabolism may be present, which may affect the concentrations of the active metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After an oral dose of radiolabeled quetiapine, less than 1% of unchanged drug was detected in the urine, suggesting that quetiapine is heavily metabolized. About 73% of a dose was detected in the urine, and about 20% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The average terminal half-life of quetiapine is about 6-7 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of quetiapine healthy volunteers in the fasted state during a clinical study was 101.04±39.11 L/h. Elderly patients may require lower doses of quetiapine, as clearance in these patients may be reduced by up to 50%. Those with liver dysfunction may also require lower doses. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 if quetiapine in rats is 2000 mg/kg. Overdose information Some signs and symptoms of a quetiapine overdose include sedation, drowsiness, tachycardia, and hypotension. Clinical trials demonstrate that overdoses of up to 30 grams of quetiapine did not result in death. A lethal outcome was reported in a clinical trial after an overdose of 13.6 grams of quetiapine. In the case of an acute overdose, ensure to maintain an airway and provide adequate ventilation and oxygenation. Gastric lavage following intubation (if necessary) along with activated charcoal and a laxative may be considered. The possibility of obtundation, seizure or dystonic reaction of the head and neck following overdose may create a risk of aspiration with induced emesis. Cardiac monitoring should also take place. A note on QT-interval prolongation in an overdose Postmarketing reports reveal increases in the cardiac QT interval in cases of quetiapine overdose, concomitant illness, and in those taking drugs that increase QT interval or affect electrolyte levels. Note that disopyramide, procainamide, and quinidine may exert additive QT-prolonging effects when administered in patients who have overdosed with quetiapine, and should be avoided. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Seroquel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Quetiapina Quétiapine Quetiapine Quetiapinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quetiapine is an atypical antipsychotic agent used for the management of bipolar disorder, schizophrenia, and major depressive disorder. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Quinidine interact?

•Drug A: Abatacept •Drug B: Quinidine •Severity: MAJOR •Description: The metabolism of Quinidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quinidine is indicated for the management and prophylactic therapy of atrial fibrillation/flutter, as well as the suppression of recurrent documented ventricular arrhythmias. It is also used in the treatment of Brugada syndrome, short QT syndrome and idiopathic ventricular fibrillation.. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quinidine is an antimalarial schizonticide, and a class Ia antiarrhythmic agent used to interrupt or prevent reentrant arrhythmias and arrhythmias due to increased automaticity, such as atrial flutter, atrial fibrillation, and paroxysmal supraventricular tachycardia. In most patients, quinidine can lead to an increase in the sinus rate. Quinidine also causes a marked prolongation of the QT interval in a dose-related manner, acts peripherally as an α-adrenergic antagonist, and has anticholinergic and negative inotropic activity. The QT interval prolongation caused by quinidine can lead to increased ventricular automaticity and polymorphic ventricular tachycardias, such as torsades de pointes. The risk of torsades is increased by bradycardia, hypokalemia, hypomagnesemia or high serum levels of quinidine. However, this type of rhythm disturbance may appear in the absence of any of them. Patients treated with quinidine may also be at risk of a paradoxical increase in ventricular rate in atrial flutter/fibrillation, and patients with sick sinus syndrome treated with quinidine may develop marked sinus node depression and bradycardia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Quinidine has a complex electrophysiological profile that has not been fully elucidated. The antiarrhythmic actions of this drug are mediated through effects on sodium channels in Purkinje fibers. Quinidine blocks the rapid sodium channel (I Na ), decreasing the phase zero of rapid depolarization of the action potential. Quinidine also reduces repolarizing K currents (I Kr, I Ks ), the inward rectifier potassium current (I K1 ), and the transient outward potassium current I to, as well as the L-type calcium current I Ca and the late I Na inward current. The reduction of these currents leads to the prolongation of the action potential duration. By shortening the plateau but prolonging late depolarization, quinidine facilitates the formation of early afterdepolarisation (EAD). Additionally, in patients with malaria, quinidine acts primarily as an intra-erythrocytic schizonticide, and is gametocidal to Plasmodium vivax and P. malariae, but not to P. falciparum. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of quinidine sulfate is approximately 70%, but it ranges from 45% to 100%. The less-than-complete quinidine sulfate bioavailability is a result of first-pass metabolism in the liver. In contrast, the absolute bioavailability of quinidine gluconate ranges from 70% to 80%, and relative to quinidine sulfate, quinidine from quinidine gluconate has a bioavailability of 1.03. The t max of quinidine sulfate extended-release tablets is approximately 6 h, while the t max of quinidine gluconate goes from 3 to 5 h. The peak serum concentration reached with immediate-release quinidine sulfate is delayed for about an hour when taken with food. Furthermore, the ingestion of grapefruit juice may decrease the rate of absorption of quinidine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Quinidine has a volume of distribution of 2-3 L/kg in healthy young adults, 0.5 L/kg in patients with congestive heart failure, and 3-5 L/kg in patients with liver cirrhosis. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): From 6.5 to 16.2 µmol/L, 80 to 88% of quinidine is bound to plasma proteins, mainly α1-acid glycoprotein and albumin. This fraction is lower in pregnant women, and it may be as low as 50 to 70% in infants and neonates. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Quinidine is mainly metabolized in the liver by cytochrome P450 enzymes, specifically CYP3A4. The major metabolite of quinidine is 3-hydroxy-quinidine, which has a volume of distribution larger than quinidine and an elimination half-life of about 12 hours. Non-clinical and clinical studies suggest that 3-hydroxy-quinidine has approximately half the antiarrhythmic activity of quinidine; therefore, this metabolite is partly responsible for the effects detected with the chronic use of quinidine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of quinidine is achieved by the renal excretion of the unchanged drug (15 to 40% of total clearance) and its hepatic biotransformation to a variety of metabolites (60 to 85% of total clearance). When urine has a pH lower than 7, 20% of administered quinidine appears in urine unchanged. However, this proportion decreases to as little as 5% as it becomes more alkaline. The renal clearance of quinidine involves both glomerular filtration and active tubular secretion, moderated by pH-dependent tubular reabsorption. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of quinidine is 6-8 hours in adults and 3-4 hours in pediatric patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of quinidine ranges from 3 to 5 mL/min/kg in adults. In pediatric patients, quinidine clearance may be two or three times as rapid. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Quinidine overdoses have been well described. The ingestion of 5 g of quinidine resulted in the death of a toddler, while an adolescent was reported to survive after ingesting 8 g of quinidine. A 16-month that ingested quinidine tablets developed a concretion of bezoar in the stomach, which led to non-declining toxic levels of quinidine. A gastric aspirate revealed that quinidine levels were 50 times higher than the ones detected in plasma. In cases of massive overdose, it may be appropriate to perform an endoscopy. Acute quinidine overdoses are characterized by ventricular arrhythmias and hypotension. Other signs and symptoms of quinidine overdose may include vomiting, diarrhea, tinnitus, high-frequency hearing loss, vertigo, blurred vision, diplopia, photophobia, headache, confusion and delirium. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nuedexta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (8R,9S)-Quinidine beta-Quinine Chinidin Chinidinum CIN-QUIN Conchinin Conquinine Pitayine Quinidina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quinidine is a medication used to restore normal sinus rhythm, treat atrial fibrillation and flutter, and treat ventricular arrhythmias.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Quinidine interact? Information: •Drug A: Abatacept •Drug B: Quinidine •Severity: MAJOR •Description: The metabolism of Quinidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quinidine is indicated for the management and prophylactic therapy of atrial fibrillation/flutter, as well as the suppression of recurrent documented ventricular arrhythmias. It is also used in the treatment of Brugada syndrome, short QT syndrome and idiopathic ventricular fibrillation.. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quinidine is an antimalarial schizonticide, and a class Ia antiarrhythmic agent used to interrupt or prevent reentrant arrhythmias and arrhythmias due to increased automaticity, such as atrial flutter, atrial fibrillation, and paroxysmal supraventricular tachycardia. In most patients, quinidine can lead to an increase in the sinus rate. Quinidine also causes a marked prolongation of the QT interval in a dose-related manner, acts peripherally as an α-adrenergic antagonist, and has anticholinergic and negative inotropic activity. The QT interval prolongation caused by quinidine can lead to increased ventricular automaticity and polymorphic ventricular tachycardias, such as torsades de pointes. The risk of torsades is increased by bradycardia, hypokalemia, hypomagnesemia or high serum levels of quinidine. However, this type of rhythm disturbance may appear in the absence of any of them. Patients treated with quinidine may also be at risk of a paradoxical increase in ventricular rate in atrial flutter/fibrillation, and patients with sick sinus syndrome treated with quinidine may develop marked sinus node depression and bradycardia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Quinidine has a complex electrophysiological profile that has not been fully elucidated. The antiarrhythmic actions of this drug are mediated through effects on sodium channels in Purkinje fibers. Quinidine blocks the rapid sodium channel (I Na ), decreasing the phase zero of rapid depolarization of the action potential. Quinidine also reduces repolarizing K currents (I Kr, I Ks ), the inward rectifier potassium current (I K1 ), and the transient outward potassium current I to, as well as the L-type calcium current I Ca and the late I Na inward current. The reduction of these currents leads to the prolongation of the action potential duration. By shortening the plateau but prolonging late depolarization, quinidine facilitates the formation of early afterdepolarisation (EAD). Additionally, in patients with malaria, quinidine acts primarily as an intra-erythrocytic schizonticide, and is gametocidal to Plasmodium vivax and P. malariae, but not to P. falciparum. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of quinidine sulfate is approximately 70%, but it ranges from 45% to 100%. The less-than-complete quinidine sulfate bioavailability is a result of first-pass metabolism in the liver. In contrast, the absolute bioavailability of quinidine gluconate ranges from 70% to 80%, and relative to quinidine sulfate, quinidine from quinidine gluconate has a bioavailability of 1.03. The t max of quinidine sulfate extended-release tablets is approximately 6 h, while the t max of quinidine gluconate goes from 3 to 5 h. The peak serum concentration reached with immediate-release quinidine sulfate is delayed for about an hour when taken with food. Furthermore, the ingestion of grapefruit juice may decrease the rate of absorption of quinidine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Quinidine has a volume of distribution of 2-3 L/kg in healthy young adults, 0.5 L/kg in patients with congestive heart failure, and 3-5 L/kg in patients with liver cirrhosis. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): From 6.5 to 16.2 µmol/L, 80 to 88% of quinidine is bound to plasma proteins, mainly α1-acid glycoprotein and albumin. This fraction is lower in pregnant women, and it may be as low as 50 to 70% in infants and neonates. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Quinidine is mainly metabolized in the liver by cytochrome P450 enzymes, specifically CYP3A4. The major metabolite of quinidine is 3-hydroxy-quinidine, which has a volume of distribution larger than quinidine and an elimination half-life of about 12 hours. Non-clinical and clinical studies suggest that 3-hydroxy-quinidine has approximately half the antiarrhythmic activity of quinidine; therefore, this metabolite is partly responsible for the effects detected with the chronic use of quinidine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of quinidine is achieved by the renal excretion of the unchanged drug (15 to 40% of total clearance) and its hepatic biotransformation to a variety of metabolites (60 to 85% of total clearance). When urine has a pH lower than 7, 20% of administered quinidine appears in urine unchanged. However, this proportion decreases to as little as 5% as it becomes more alkaline. The renal clearance of quinidine involves both glomerular filtration and active tubular secretion, moderated by pH-dependent tubular reabsorption. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of quinidine is 6-8 hours in adults and 3-4 hours in pediatric patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of quinidine ranges from 3 to 5 mL/min/kg in adults. In pediatric patients, quinidine clearance may be two or three times as rapid. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Quinidine overdoses have been well described. The ingestion of 5 g of quinidine resulted in the death of a toddler, while an adolescent was reported to survive after ingesting 8 g of quinidine. A 16-month that ingested quinidine tablets developed a concretion of bezoar in the stomach, which led to non-declining toxic levels of quinidine. A gastric aspirate revealed that quinidine levels were 50 times higher than the ones detected in plasma. In cases of massive overdose, it may be appropriate to perform an endoscopy. Acute quinidine overdoses are characterized by ventricular arrhythmias and hypotension. Other signs and symptoms of quinidine overdose may include vomiting, diarrhea, tinnitus, high-frequency hearing loss, vertigo, blurred vision, diplopia, photophobia, headache, confusion and delirium. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nuedexta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (8R,9S)-Quinidine beta-Quinine Chinidin Chinidinum CIN-QUIN Conchinin Conquinine Pitayine Quinidina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quinidine is a medication used to restore normal sinus rhythm, treat atrial fibrillation and flutter, and treat ventricular arrhythmias. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Quinine interact?

•Drug A: Abatacept •Drug B: Quinine •Severity: MODERATE •Description: The metabolism of Quinine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malaria and leg cramps •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quinine is used parenterally to treat life-threatening infections caused by chloroquine-resistant Plasmodium falciparum malaria. Quinine acts as a blood schizonticide although it also has gametocytocidal activity against P. vivax and P. malariae. Because it is a weak base, it is concentrated in the food vacuoles of P. falciparum. It is thought to act by inhibiting heme polymerase, thereby allowing accumulation of its cytotoxic substrate, heme. As a schizonticidal drug, it is less effective and more toxic than chloroquine. However, it has a special place in the management of severe falciparum malaria in areas with known resistance to chloroquine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The theorized mechanism of action for quinine and related anti-malarial drugs is that these drugs are toxic to the malaria parasite. Specifically, the drugs interfere with the parasite's ability to break down and digest hemoglobin. Consequently, the parasite starves and/or builds up toxic levels of partially degraded hemoglobin in itself. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 76 - 88% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 1.43 ± 0.18 L/kg [Healthy Pediatric Controls] 0.87 ± 0.12 L/kg [P. falciparum Malaria Pediatric Patients] 2.5 to 7.1 L/kg [healthy subjects who received a single oral 600 mg dose] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 70% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, over 80% metabolized by the liver. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Quinine is eliminated primarily via hepatic biotransformation. Approximately 20% of quinine is excreted unchanged in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 18 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 0.17 L/h/kg [healthy] 0.09 L/h/kg [patients with uncomplicated malaria] 18.4 L/h [healthy adult subjects with administration of multiple-dose activated charcoal] 11.8 L/h [healthy adult subjects without administration of multiple-dose activated charcoal] Oral cl=0.06 L/h/kg [elderly subjects] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Quinine is a documented causative agent of drug induced thrombocytopenia (DIT). Thrombocytopenia is a low amount of platelets in the blood. Quinine induces production of antibodies against glycoprotein (GP) Ib-IX complex in the majority of cases of DIT, or more rarely, the platelet-glycoprotein complex GPIIb-IIIa. Increased antibodies against these complexes increases platelet clearance, leading to the observed thrombocytopenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Qualaquin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (8S,9R)-quinine 6'-Methoxycinchonidine Chinin Chinine Chininum Quinina Quinine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quinine is an alkaloid used to treat uncomplicated Plasmodium falciparum malaria.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Quinine interact? Information: •Drug A: Abatacept •Drug B: Quinine •Severity: MODERATE •Description: The metabolism of Quinine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malaria and leg cramps •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quinine is used parenterally to treat life-threatening infections caused by chloroquine-resistant Plasmodium falciparum malaria. Quinine acts as a blood schizonticide although it also has gametocytocidal activity against P. vivax and P. malariae. Because it is a weak base, it is concentrated in the food vacuoles of P. falciparum. It is thought to act by inhibiting heme polymerase, thereby allowing accumulation of its cytotoxic substrate, heme. As a schizonticidal drug, it is less effective and more toxic than chloroquine. However, it has a special place in the management of severe falciparum malaria in areas with known resistance to chloroquine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The theorized mechanism of action for quinine and related anti-malarial drugs is that these drugs are toxic to the malaria parasite. Specifically, the drugs interfere with the parasite's ability to break down and digest hemoglobin. Consequently, the parasite starves and/or builds up toxic levels of partially degraded hemoglobin in itself. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 76 - 88% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 1.43 ± 0.18 L/kg [Healthy Pediatric Controls] 0.87 ± 0.12 L/kg [P. falciparum Malaria Pediatric Patients] 2.5 to 7.1 L/kg [healthy subjects who received a single oral 600 mg dose] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 70% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, over 80% metabolized by the liver. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Quinine is eliminated primarily via hepatic biotransformation. Approximately 20% of quinine is excreted unchanged in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 18 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 0.17 L/h/kg [healthy] 0.09 L/h/kg [patients with uncomplicated malaria] 18.4 L/h [healthy adult subjects with administration of multiple-dose activated charcoal] 11.8 L/h [healthy adult subjects without administration of multiple-dose activated charcoal] Oral cl=0.06 L/h/kg [elderly subjects] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Quinine is a documented causative agent of drug induced thrombocytopenia (DIT). Thrombocytopenia is a low amount of platelets in the blood. Quinine induces production of antibodies against glycoprotein (GP) Ib-IX complex in the majority of cases of DIT, or more rarely, the platelet-glycoprotein complex GPIIb-IIIa. Increased antibodies against these complexes increases platelet clearance, leading to the observed thrombocytopenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Qualaquin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (8S,9R)-quinine 6'-Methoxycinchonidine Chinin Chinine Chininum Quinina Quinine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quinine is an alkaloid used to treat uncomplicated Plasmodium falciparum malaria. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Quizartinib interact?

•Drug A: Abatacept •Drug B: Quizartinib •Severity: MODERATE •Description: The metabolism of Quizartinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quizartinib is indicated in combination with standard cytarabine and anthracycline induction and cytarabine consolidation, and as maintenance monotherapy following consolidation chemotherapy, for the treatment of adult patients with newly diagnosed acute myeloid leukemia (AML) that is FLT3 internal tandem duplication (ITD)-positive as detected by an FDA-approved test. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quizartinib showed antitumor activity in a mouse model of FLT3-ITD-dependent leukemia. In vitro, studies have shown that quizartinib is a predominant inhibitor of the slow delayed rectifier potassium current, IKs. In AML patients receiving quizartinib at a dose of 90 mg/day for females and 135 mg/day for males on a 28-day schedule, the median levels of phospho-FLT3 (pFLT3) and total FLT3 (tFLT3) decreased from 3312 RLU or 5639 RLU respectively at day 1 to 1235 RLU and 142 RLU respectively at day 8. Additionally, pFLT3 levels are statistically significantly higher (p < 0.0001, Mann Whitney test) for the ITD+ subjects on day 1; however, pFLT3 levels was reduced to a similar level in patients with or without the ITD mutation. The exposure-response analysis predicted a concentration-dependent QTcF interval median prolongation of 18 and 24 ms [upper bound of 2-sided 90% confidence interval (CI): 21 and 27 ms] at the median steady-state Cmax of quizartinib at the 26.5 mg and 53 mg dose level during maintenance therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Quizartinib is a small molecule inhibitor of the receptor tyrosine kinase FLT3. Quizartinib and its major active metabolite AC886 bind to the adenosine triphosphate (ATP) binding domain of FLT3 with comparable affinity, and both had 10-fold lower affinity towards FLT3-ITD mutation compared to FLT3 in a binding assay. Quizartinib and AC886 inhibited FLT3 kinase activity, preventing autophosphorylation of the receptor, thereby inhibiting downstream FLT3 receptor signaling and blocking FLT3-ITD-dependent cell proliferation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The mean (SD) absolute bioavailability of quizartinib from the tablet formulation was 71% (±7%) in healthy subjects. After oral administration under fasted conditions, time to peak concentration (median T max ) of quizartinib and AC886 measured post dose was approximately 4 hours (range 2 to 8 hours) and 5 to 6 hours (range 4 to 120 hours), respectively, in healthy subjects. Following the administration of 35.4 mg quizartinib once daily in patients with newly diagnosed acute myeloid leukemia, the C max and AUC 0-24h were calculated to be 140 ng/mL (71%) and 2,680 ng.h/mL (85%) respectively during the induction therapy and 204 ng/mL (64%) and 3,930 ng.h/mL (78%) respectively during the consolidation therapy. For the metabolite AC886, the C max and AUC 0-24h were estimated to be 163 ng/mL (52%) and 3,590 ng.h/mL (51%) respectively during the induction therapy and 172 ng/mL (47%) and 3,800 ng.h/mL (46%) respectively during the consolidation therapy. Increasing the once daily dose of quizartinib to 53 mg also increases the C max and AUC 0-24h of quizartinib to 529 ng/mL (60%) and 10,200 ng.h/mL (75%) respectively at steady state. The C max and AUC 0-24h of the metabolite AC886 also increases to 262 ng/mL (48%) and 5,790 ng•h/mL (46%) respectively. No clinically significant differences in the pharmacokinetics of quizartinib were observed when administered with a high-fat, high-calorie meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state in healthy subjects was estimated to be 275 L (17%). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding of quizartinib and AC886 is 99% or greater. In vitro blood-to-plasma ratio for quizartinib and AC886 ranges from 0.79-1.30 and 1.36-3.19, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro quizartinib is primarily metabolized via oxidation by CYP3A4/5 and AC886 is formed and metabolized by CYP3A4/5. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single radiolabeled dose of quizartinib 53 mg to healthy subjects, 76.3% of the total radioactivity was recovered in feces (4% unchanged) and 1.64% in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (SD) effective half-lives (t1/2) in patients with newly diagnosed AML for quizartinib and AC886 during maintenance therapy are 81 hours (±73) and 136 hours (±113), respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Total body clearance of quizartinib in healthy subjects was estimated to be 2.23 L/hour (29%). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Based on findings from animal studies and its mechanism of action, quizartinib can cause embryo-fetal harm when administered to a pregnant woman. There are no available data on quizartinib use in pregnant women to evaluate for a drug-associated risk. In animal reproduction studies, oral administration of quizartinib to pregnant rats during organogenesis resulted in adverse developmental outcomes including structural abnormalities and alterations to growth at maternal exposures approximately 3 times those in patients at the maximum recommended human dose (MRHD) of 53 mg/day (see Data). Advise pregnant women of the potential risk to a fetus. Carcinogenicity studies have not been conducted with quizartinib. Quizartinib was mutagenic in a bacterial reverse mutation (Ames) assay and not mutagenic in an in vivo transgenic rat mutation assay. Quizartinib was not genotoxic in vitro in mouse lymphoma thymidine kinase mutation and human lymphocyte chromosome aberration assays, or in an in vivo rat bone marrow micronucleus assay. Fertility studies in animals have not been conducted with quizartinib. However, adverse findings in male and female reproductive systems were observed in repeat dose toxicity studies in rats and monkeys. Findings in female animals (rats or monkeys) included ovarian cysts, vaginal mucosal modifications, and atrophy of the uterus, ovary, and vagina, starting at exposures (AUC) approximately 0.2 times the MRHD of 53 mg/day. In male animals (rats and monkeys), findings included testicular seminiferous tubular degeneration, failure of sperm release, germ cell depletion in the testes, and oligospermia/aspermia, starting at exposures approximately 0.4 times the MRHD. After approximately one month of recovery period, all these findings except the vaginal mucosal modifications in the female rats were reversible. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vanflyta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Quizartinib Quizartinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quizartinib is a FLT3 inhibitor used in combination with cytarabine and anthracycline to treat acute myeloid leukemia with FLT3 internal tandem duplication

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Quizartinib interact? Information: •Drug A: Abatacept •Drug B: Quizartinib •Severity: MODERATE •Description: The metabolism of Quizartinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Quizartinib is indicated in combination with standard cytarabine and anthracycline induction and cytarabine consolidation, and as maintenance monotherapy following consolidation chemotherapy, for the treatment of adult patients with newly diagnosed acute myeloid leukemia (AML) that is FLT3 internal tandem duplication (ITD)-positive as detected by an FDA-approved test. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Quizartinib showed antitumor activity in a mouse model of FLT3-ITD-dependent leukemia. In vitro, studies have shown that quizartinib is a predominant inhibitor of the slow delayed rectifier potassium current, IKs. In AML patients receiving quizartinib at a dose of 90 mg/day for females and 135 mg/day for males on a 28-day schedule, the median levels of phospho-FLT3 (pFLT3) and total FLT3 (tFLT3) decreased from 3312 RLU or 5639 RLU respectively at day 1 to 1235 RLU and 142 RLU respectively at day 8. Additionally, pFLT3 levels are statistically significantly higher (p < 0.0001, Mann Whitney test) for the ITD+ subjects on day 1; however, pFLT3 levels was reduced to a similar level in patients with or without the ITD mutation. The exposure-response analysis predicted a concentration-dependent QTcF interval median prolongation of 18 and 24 ms [upper bound of 2-sided 90% confidence interval (CI): 21 and 27 ms] at the median steady-state Cmax of quizartinib at the 26.5 mg and 53 mg dose level during maintenance therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Quizartinib is a small molecule inhibitor of the receptor tyrosine kinase FLT3. Quizartinib and its major active metabolite AC886 bind to the adenosine triphosphate (ATP) binding domain of FLT3 with comparable affinity, and both had 10-fold lower affinity towards FLT3-ITD mutation compared to FLT3 in a binding assay. Quizartinib and AC886 inhibited FLT3 kinase activity, preventing autophosphorylation of the receptor, thereby inhibiting downstream FLT3 receptor signaling and blocking FLT3-ITD-dependent cell proliferation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The mean (SD) absolute bioavailability of quizartinib from the tablet formulation was 71% (±7%) in healthy subjects. After oral administration under fasted conditions, time to peak concentration (median T max ) of quizartinib and AC886 measured post dose was approximately 4 hours (range 2 to 8 hours) and 5 to 6 hours (range 4 to 120 hours), respectively, in healthy subjects. Following the administration of 35.4 mg quizartinib once daily in patients with newly diagnosed acute myeloid leukemia, the C max and AUC 0-24h were calculated to be 140 ng/mL (71%) and 2,680 ng.h/mL (85%) respectively during the induction therapy and 204 ng/mL (64%) and 3,930 ng.h/mL (78%) respectively during the consolidation therapy. For the metabolite AC886, the C max and AUC 0-24h were estimated to be 163 ng/mL (52%) and 3,590 ng.h/mL (51%) respectively during the induction therapy and 172 ng/mL (47%) and 3,800 ng.h/mL (46%) respectively during the consolidation therapy. Increasing the once daily dose of quizartinib to 53 mg also increases the C max and AUC 0-24h of quizartinib to 529 ng/mL (60%) and 10,200 ng.h/mL (75%) respectively at steady state. The C max and AUC 0-24h of the metabolite AC886 also increases to 262 ng/mL (48%) and 5,790 ng•h/mL (46%) respectively. No clinically significant differences in the pharmacokinetics of quizartinib were observed when administered with a high-fat, high-calorie meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state in healthy subjects was estimated to be 275 L (17%). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding of quizartinib and AC886 is 99% or greater. In vitro blood-to-plasma ratio for quizartinib and AC886 ranges from 0.79-1.30 and 1.36-3.19, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro quizartinib is primarily metabolized via oxidation by CYP3A4/5 and AC886 is formed and metabolized by CYP3A4/5. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single radiolabeled dose of quizartinib 53 mg to healthy subjects, 76.3% of the total radioactivity was recovered in feces (4% unchanged) and 1.64% in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (SD) effective half-lives (t1/2) in patients with newly diagnosed AML for quizartinib and AC886 during maintenance therapy are 81 hours (±73) and 136 hours (±113), respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Total body clearance of quizartinib in healthy subjects was estimated to be 2.23 L/hour (29%). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Based on findings from animal studies and its mechanism of action, quizartinib can cause embryo-fetal harm when administered to a pregnant woman. There are no available data on quizartinib use in pregnant women to evaluate for a drug-associated risk. In animal reproduction studies, oral administration of quizartinib to pregnant rats during organogenesis resulted in adverse developmental outcomes including structural abnormalities and alterations to growth at maternal exposures approximately 3 times those in patients at the maximum recommended human dose (MRHD) of 53 mg/day (see Data). Advise pregnant women of the potential risk to a fetus. Carcinogenicity studies have not been conducted with quizartinib. Quizartinib was mutagenic in a bacterial reverse mutation (Ames) assay and not mutagenic in an in vivo transgenic rat mutation assay. Quizartinib was not genotoxic in vitro in mouse lymphoma thymidine kinase mutation and human lymphocyte chromosome aberration assays, or in an in vivo rat bone marrow micronucleus assay. Fertility studies in animals have not been conducted with quizartinib. However, adverse findings in male and female reproductive systems were observed in repeat dose toxicity studies in rats and monkeys. Findings in female animals (rats or monkeys) included ovarian cysts, vaginal mucosal modifications, and atrophy of the uterus, ovary, and vagina, starting at exposures (AUC) approximately 0.2 times the MRHD of 53 mg/day. In male animals (rats and monkeys), findings included testicular seminiferous tubular degeneration, failure of sperm release, germ cell depletion in the testes, and oligospermia/aspermia, starting at exposures approximately 0.4 times the MRHD. After approximately one month of recovery period, all these findings except the vaginal mucosal modifications in the female rats were reversible. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vanflyta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Quizartinib Quizartinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Quizartinib is a FLT3 inhibitor used in combination with cytarabine and anthracycline to treat acute myeloid leukemia with FLT3 internal tandem duplication Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Rabeprazole interact?

•Drug A: Abatacept •Drug B: Rabeprazole •Severity: MODERATE •Description: The metabolism of Rabeprazole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of acid-reflux disorders (GERD), peptic ulcer disease, H. pylori eradication, and prevention of gastroinetestinal bleeds with NSAID use. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rabeprazole prevents the production of acid in the stomach. It reduces symptoms and prevents injury to the esophagus or stomach in patients with gastroesophageal reflux disease (GERD) or ulcers. Rabeprazole is also useful in conditions that produce too much stomach acid such as Zollinger-Ellison syndrome. Rabeprazole may also be used with antibiotics to get rid of bacteria that are associated with some ulcers. Rabeprazole is a selective and irreversible proton pump inhibitor, suppresses gastric acid secretion by specific inhibition of the H, K -ATPase, which is found at the secretory surface of parietal cells. In doing so, it inhibits the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rabeprazole belongs to a class of antisecretory compounds (substituted benzimidazole proton-pump inhibitors) that do not exhibit anticholinergic or histamine H2-receptor antagonist properties, but suppress gastric acid secretion by inhibiting the gastric H /K ATPase (hydrogen-potassium adenosine triphosphatase) at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, rabeprazole has been characterized as a gastric proton-pump inhibitor. Rabeprazole blocks the final step of gastric acid secretion. In gastric parietal cells, rabeprazole is protonated, accumulates, and is transformed to an active sulfenamide. When studied in vitro, rabeprazole is chemically activated at pH 1.2 with a half-life of 78 seconds. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absolute bioavailability is approximately 52%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96.3% (bound to human plasma proteins) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single 20 mg oral dose of 14C-labeled rabeprazole, approximately 90% of the drug was eliminated in the urine, primarily as thioether carboxylic acid; its glucuronide, and mercapturic acid metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1-2 hours (in plasma) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aciphex, Pariet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rabeprazole is a proton pump inhibitor used to help gastrointestinal ulcers heal, to treat symptoms of gastroesophageal reflux disease (GERD), to eradicate Helicobacter pylori, and to treat hypersecretory conditions such as Zollinger-Ellison Syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rabeprazole interact? Information: •Drug A: Abatacept •Drug B: Rabeprazole •Severity: MODERATE •Description: The metabolism of Rabeprazole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of acid-reflux disorders (GERD), peptic ulcer disease, H. pylori eradication, and prevention of gastroinetestinal bleeds with NSAID use. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rabeprazole prevents the production of acid in the stomach. It reduces symptoms and prevents injury to the esophagus or stomach in patients with gastroesophageal reflux disease (GERD) or ulcers. Rabeprazole is also useful in conditions that produce too much stomach acid such as Zollinger-Ellison syndrome. Rabeprazole may also be used with antibiotics to get rid of bacteria that are associated with some ulcers. Rabeprazole is a selective and irreversible proton pump inhibitor, suppresses gastric acid secretion by specific inhibition of the H, K -ATPase, which is found at the secretory surface of parietal cells. In doing so, it inhibits the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rabeprazole belongs to a class of antisecretory compounds (substituted benzimidazole proton-pump inhibitors) that do not exhibit anticholinergic or histamine H2-receptor antagonist properties, but suppress gastric acid secretion by inhibiting the gastric H /K ATPase (hydrogen-potassium adenosine triphosphatase) at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, rabeprazole has been characterized as a gastric proton-pump inhibitor. Rabeprazole blocks the final step of gastric acid secretion. In gastric parietal cells, rabeprazole is protonated, accumulates, and is transformed to an active sulfenamide. When studied in vitro, rabeprazole is chemically activated at pH 1.2 with a half-life of 78 seconds. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absolute bioavailability is approximately 52%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96.3% (bound to human plasma proteins) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single 20 mg oral dose of 14C-labeled rabeprazole, approximately 90% of the drug was eliminated in the urine, primarily as thioether carboxylic acid; its glucuronide, and mercapturic acid metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1-2 hours (in plasma) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aciphex, Pariet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rabeprazole is a proton pump inhibitor used to help gastrointestinal ulcers heal, to treat symptoms of gastroesophageal reflux disease (GERD), to eradicate Helicobacter pylori, and to treat hypersecretory conditions such as Zollinger-Ellison Syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Rabies immune globulin, human interact?

•Drug A: Abatacept •Drug B: Rabies immune globulin, human •Severity: MODERATE •Description: The therapeutic efficacy of Rabies immune globulin, human can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The human rabies immune globulin is used indicated for passive, transient post-exposure prophylaxis of rabies infection to persons of all ages when given immediately after contact with a rabid or possibly rabid animal. It should be administered concurrently with a full course of rabies vaccine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rabies immune globulin prevents viral invasion of the central nervous system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rabies immune globulin binds the rabies virus, preventing it from invading the central nervous system. This affords time for the rabies vaccine, which is also administered in cases of rabies exposure, to induce an immune response to destroy the virus. Rabies immunoglobulin should only be administered up to eight days after exposure as the host begins to produce sufficient antibodies to the virus one week after exposure. Repeat dosing should also be avoided as it may interfere with induction of immune response by the rabies vaccine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicological studies have been performed. Isolated cases of angioneurotic edema, skin rash, nephrotic syndrome, and anaphylactic shock after injection have been noted. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hyperrab, Imogam, Kedrab, Rabavert •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rabies immune globulin, human is a solution of antibodies used to prevent rabies after an exposure.

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Rabies immune globulin, human interact? Information: •Drug A: Abatacept •Drug B: Rabies immune globulin, human •Severity: MODERATE •Description: The therapeutic efficacy of Rabies immune globulin, human can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The human rabies immune globulin is used indicated for passive, transient post-exposure prophylaxis of rabies infection to persons of all ages when given immediately after contact with a rabid or possibly rabid animal. It should be administered concurrently with a full course of rabies vaccine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rabies immune globulin prevents viral invasion of the central nervous system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rabies immune globulin binds the rabies virus, preventing it from invading the central nervous system. This affords time for the rabies vaccine, which is also administered in cases of rabies exposure, to induce an immune response to destroy the virus. Rabies immunoglobulin should only be administered up to eight days after exposure as the host begins to produce sufficient antibodies to the virus one week after exposure. Repeat dosing should also be avoided as it may interfere with induction of immune response by the rabies vaccine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicological studies have been performed. Isolated cases of angioneurotic edema, skin rash, nephrotic syndrome, and anaphylactic shock after injection have been noted. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hyperrab, Imogam, Kedrab, Rabavert •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rabies immune globulin, human is a solution of antibodies used to prevent rabies after an exposure. Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Rabies virus inactivated antigen, A interact?

•Drug A: Abatacept •Drug B: Rabies virus inactivated antigen, A •Severity: MODERATE •Description: The therapeutic efficacy of Rabies virus inactivated antigen, A can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Rabies virus inactivated antigen, A interact? Information: •Drug A: Abatacept •Drug B: Rabies virus inactivated antigen, A •Severity: MODERATE •Description: The therapeutic efficacy of Rabies virus inactivated antigen, A can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Rabies virus inactivated antigen, B interact?

•Drug A: Abatacept •Drug B: Rabies virus inactivated antigen, B •Severity: MODERATE •Description: The therapeutic efficacy of Rabies virus inactivated antigen, B can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Rabies virus inactivated antigen, B interact? Information: •Drug A: Abatacept •Drug B: Rabies virus inactivated antigen, B •Severity: MODERATE •Description: The therapeutic efficacy of Rabies virus inactivated antigen, B can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Raltitrexed interact?

•Drug A: Abatacept •Drug B: Raltitrexed •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Raltitrexed is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malignant neoplasm of colon and rectum •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Raltitrexed belongs to a group of medicines known as antimetabolites. It is used to treat cancer of the colon and rectum. It may also be used to treat other kinds of cancer, as determined by your doctor. Raltitrexed blocks an enzyme needed by the cell to live. This interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by raltitrexed, other effects will also occur. Some of these may be serious and must be reported to your doctor. Other effects, like hair loss, may not be serious but may cause concern. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Raltitrexed is an antineoplastic Agents and folic acid antagonists. Raltitrexed inhibits thymidylate synthase (TS) leading to DNA fragmentation and cell death. It is transported into cells via a reduced folate carrier. Inside the cell Raltitrexed is extensively polyglutamated, which enhances thymidylate synthase inhibitory power and duration. Inhibition of this enzyme results in decreased synthesis of thymidine triphosphate which is required for DNA synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >93% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Raltitrexed is transported into cells via a reduced folate carrier. Inside the cell it is extensively polyglutamated by the enzyme folyl polyglutamate synthetase to polyglutamate forms. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 198 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include pale skin, troubled breathing, unusual bleeding or bruising, unusual tiredness or weakness, black, tarry stools, chest pain, chills, cough, fever, painful or difficult urination, shortness of breath, sore throat, sores, ulcers, or white spots on lips or in mouth, swollen glands, increase in bowel movements, loose stools, soft stools. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tomudex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Raltitrexed is a folate analog thymidylate synthase inhibitor used in the treatment of advanced colorectal cancer.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Raltitrexed interact? Information: •Drug A: Abatacept •Drug B: Raltitrexed •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Raltitrexed is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malignant neoplasm of colon and rectum •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Raltitrexed belongs to a group of medicines known as antimetabolites. It is used to treat cancer of the colon and rectum. It may also be used to treat other kinds of cancer, as determined by your doctor. Raltitrexed blocks an enzyme needed by the cell to live. This interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by raltitrexed, other effects will also occur. Some of these may be serious and must be reported to your doctor. Other effects, like hair loss, may not be serious but may cause concern. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Raltitrexed is an antineoplastic Agents and folic acid antagonists. Raltitrexed inhibits thymidylate synthase (TS) leading to DNA fragmentation and cell death. It is transported into cells via a reduced folate carrier. Inside the cell Raltitrexed is extensively polyglutamated, which enhances thymidylate synthase inhibitory power and duration. Inhibition of this enzyme results in decreased synthesis of thymidine triphosphate which is required for DNA synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >93% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Raltitrexed is transported into cells via a reduced folate carrier. Inside the cell it is extensively polyglutamated by the enzyme folyl polyglutamate synthetase to polyglutamate forms. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 198 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include pale skin, troubled breathing, unusual bleeding or bruising, unusual tiredness or weakness, black, tarry stools, chest pain, chills, cough, fever, painful or difficult urination, shortness of breath, sore throat, sores, ulcers, or white spots on lips or in mouth, swollen glands, increase in bowel movements, loose stools, soft stools. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tomudex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Raltitrexed is a folate analog thymidylate synthase inhibitor used in the treatment of advanced colorectal cancer. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Ramelteon interact?

•Drug A: Abatacept •Drug B: Ramelteon •Severity: MODERATE •Description: The metabolism of Ramelteon can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of insomnia characterized by difficulty with sleep onset. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ramelteon is the first selective melatonin agonist. It works by mimicking melatonin (MT), a naturally occuring hormone that is produced during the sleep period and thought to be responsible for the regulation of circadian rhythm underlying the normal sleep-wake cycle. Ramelteon has a high affinity for the MT 1 and MT 2 receptors. The MT 1 and MT 2 receptors are located in the brain's suprachiasmatic nuclei (SCN),which is known as the body's "master clock" because it regulates the 24-hour sleep-wake cycle. Ramelteon has an active metabolite that is less potent but circulates in higher concentrations than the parent compound. The metabolite also has weak affinity for the 5HT2b receptor. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ramelteon is a melatonin receptor agonist with both high affinity for melatonin MT 1 and MT 2 receptors, and lower selectivity for the MT 3 receptor. Melatonin production is concurrent with nocturnal sleep, meaning that an increase in melatonin levels is related to the onset of self-reported sleepiness and an increase in sleep propensity. MT 1 receptors are believed to be responsible for regulation of sleepiness and facilitation of sleep onset, and MT 2 receptors are believed to mediate phase-shifting effects of melatonin on the circadian rhythm. While MT 1 and MT 2 receptors are associated with the sleep-wake cycle, MT 3 has a completely different profile, and therefore is not likely to be involved in the sleep-wake cycle. Remelteon has no appreciable affinity for the gamma-aminobutyric acid (GABA) receptor complex or receptors that bind neuropeptides, cytokines, serotonin, dopamine, norepinephrine, acetylcholine, or opiates. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapid, total absorption is at least 84%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 73.6 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~82% (in human serum) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled ramelteon, 84% of total radioactivity was excreted in urine and approximately 4% in feces, resulting in a mean recovery of 88%. Less than 0.1% of the dose was excreted in urine and feces as the parent compound. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~1-2.6 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rozerem •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ramelteon is a melatonin receptor agonist used to treat insomnia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ramelteon interact? Information: •Drug A: Abatacept •Drug B: Ramelteon •Severity: MODERATE •Description: The metabolism of Ramelteon can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of insomnia characterized by difficulty with sleep onset. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ramelteon is the first selective melatonin agonist. It works by mimicking melatonin (MT), a naturally occuring hormone that is produced during the sleep period and thought to be responsible for the regulation of circadian rhythm underlying the normal sleep-wake cycle. Ramelteon has a high affinity for the MT 1 and MT 2 receptors. The MT 1 and MT 2 receptors are located in the brain's suprachiasmatic nuclei (SCN),which is known as the body's "master clock" because it regulates the 24-hour sleep-wake cycle. Ramelteon has an active metabolite that is less potent but circulates in higher concentrations than the parent compound. The metabolite also has weak affinity for the 5HT2b receptor. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ramelteon is a melatonin receptor agonist with both high affinity for melatonin MT 1 and MT 2 receptors, and lower selectivity for the MT 3 receptor. Melatonin production is concurrent with nocturnal sleep, meaning that an increase in melatonin levels is related to the onset of self-reported sleepiness and an increase in sleep propensity. MT 1 receptors are believed to be responsible for regulation of sleepiness and facilitation of sleep onset, and MT 2 receptors are believed to mediate phase-shifting effects of melatonin on the circadian rhythm. While MT 1 and MT 2 receptors are associated with the sleep-wake cycle, MT 3 has a completely different profile, and therefore is not likely to be involved in the sleep-wake cycle. Remelteon has no appreciable affinity for the gamma-aminobutyric acid (GABA) receptor complex or receptors that bind neuropeptides, cytokines, serotonin, dopamine, norepinephrine, acetylcholine, or opiates. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapid, total absorption is at least 84%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 73.6 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~82% (in human serum) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled ramelteon, 84% of total radioactivity was excreted in urine and approximately 4% in feces, resulting in a mean recovery of 88%. Less than 0.1% of the dose was excreted in urine and feces as the parent compound. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~1-2.6 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rozerem •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ramelteon is a melatonin receptor agonist used to treat insomnia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Ranitidine interact?

•Drug A: Abatacept •Drug B: Ranitidine •Severity: MODERATE •Description: The metabolism of Ranitidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): This drug is used alone or with concomitant antacids for the following conditions: short-term treatment of active duodenal ulcer, treating gastric acid hypersecretion due to Zollinger-Ellison syndrome, systemic mastocytosis, and other conditions that may pathologically raise gastric acid levels. It also used in the short term treatment of active benign gastric ulcers and maintenance therapy of gastric ulcers at a reduced dose. In addition to the above, ranitidine can be used for the treatment of GERD symptoms, treatment of erosive esophagitis (endoscopically diagnosed) and the maintenance of gastric or duodenal ulcer healing. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ranitidine decreases the secretion of gastric acid stimulated by food and drugs. It also reduces the secretion of gastric acid in hypersecretory conditions such as Zollinger-Ellison syndrome. Marked improvements in the appearance of the esophageal tissues have been observed by endoscopic imaging after ranitidine therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): After a meal, the hormone gastrin, produced by cells in the lining of the stomach, stimulates the release of histamine, which then binds to histamine H2 receptors, leading to the secretion of gastric acid. Ranitidine reduces the secretion of gastric acid by reversible binding to histamine (H2) receptors, which are found on gastric parietal cells. This process leads to the inhibition of histamine binding to this receptor, causing the reduction of gastric acid secretion. The relief of gastric-acid related symptoms can occur as soon as 60 minutes after administration of a single dose, and the effects can last from 4-10 hours, providing fast and effective symptomatic relief. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ranitidine is rapidly absorbed with peak concentrations reached within 1-3 hours after administration, and varying greatly among patients. Bioavailability is about 50%-60% due to hepatic metabolism. In a pharmacokinetic study of healthy males, the AUC 0-infinity was about 2,488.6 ng x h/mL and the median Tmax was 2.83 hours. Food or antacids have limited effects on absorption. One clinical study found that the administration of a potent antacid (150 mmol) in subjects in the fasted state led to decreased absorption of ranitidine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution is higher than body volume, and measures at approximately 1.4 L/kg. It concentrates in breast milk, but does not readily distribute into the cerebrospinal fluid. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of ranitidine is approximately 15%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite in the urine is N-oxide, which represents less than 4% of the dose. Other metabolites of ranitidine include S-oxide (1%) and desmethyl ranitidine (1%). The feces contain the remainder of the excreted ranitidine dose. Liver dysfunction has been shown to cause small, but clinically insignificant, changes in various ranitidine pharmacokinetic parameters. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): This drug is mainly excreted in the urine but also excreted in the feces. About 30% of a single oral dose has been measured in the urine as unchanged drug within 24 hours of ingestion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life or ranitidine is about 2.5-3 hours. It may be longer after oral administration versus injection. The plasma half-life is longer for elderly patients population due to a decrease in renal function, and is measured at 3-4 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance is about 410 mL/min according to FDA prescribing information. Another resource mentions a plasma clearance of approximately 600 ml/min. Clearance is decreased in the elderly and those with impaired or hepatic renal function. It is recommended to decrease the dose of ranitidine by one-half in patients with renal impairment. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral doses of 1,000 mg/kg in mice and rats were not found to be lethal. Intravenous LD50 values in mice and rats were 77 and 83 mg/kg, respectively. Overdose information There has been limited experience with ranitidine overdose. Reported acute ingestions of up to 18 grams orally were followed by temporary adverse effects similar to the normal adverse effects of this drug, including tachycardia, bradycardia, dizziness, diarrhea, nausea, and vomiting, among other effects. Gait abnormalities and hypotension have also been observed. When an overdose with ranitidine is suspected, remove unabsorbed ranitidine from the gastrointestinal tract if possible, and monitor the patient and provide supportive therapy as required. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Good Sense Acid Reducer, Wal-zan, Zantac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ranitidine is a histamine H2 antagonist used to treat duodenal ulcers, Zollinger-Ellison syndrome, gastric ulcers, GERD, and erosive esophagitis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ranitidine interact? Information: •Drug A: Abatacept •Drug B: Ranitidine •Severity: MODERATE •Description: The metabolism of Ranitidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): This drug is used alone or with concomitant antacids for the following conditions: short-term treatment of active duodenal ulcer, treating gastric acid hypersecretion due to Zollinger-Ellison syndrome, systemic mastocytosis, and other conditions that may pathologically raise gastric acid levels. It also used in the short term treatment of active benign gastric ulcers and maintenance therapy of gastric ulcers at a reduced dose. In addition to the above, ranitidine can be used for the treatment of GERD symptoms, treatment of erosive esophagitis (endoscopically diagnosed) and the maintenance of gastric or duodenal ulcer healing. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ranitidine decreases the secretion of gastric acid stimulated by food and drugs. It also reduces the secretion of gastric acid in hypersecretory conditions such as Zollinger-Ellison syndrome. Marked improvements in the appearance of the esophageal tissues have been observed by endoscopic imaging after ranitidine therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): After a meal, the hormone gastrin, produced by cells in the lining of the stomach, stimulates the release of histamine, which then binds to histamine H2 receptors, leading to the secretion of gastric acid. Ranitidine reduces the secretion of gastric acid by reversible binding to histamine (H2) receptors, which are found on gastric parietal cells. This process leads to the inhibition of histamine binding to this receptor, causing the reduction of gastric acid secretion. The relief of gastric-acid related symptoms can occur as soon as 60 minutes after administration of a single dose, and the effects can last from 4-10 hours, providing fast and effective symptomatic relief. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ranitidine is rapidly absorbed with peak concentrations reached within 1-3 hours after administration, and varying greatly among patients. Bioavailability is about 50%-60% due to hepatic metabolism. In a pharmacokinetic study of healthy males, the AUC 0-infinity was about 2,488.6 ng x h/mL and the median Tmax was 2.83 hours. Food or antacids have limited effects on absorption. One clinical study found that the administration of a potent antacid (150 mmol) in subjects in the fasted state led to decreased absorption of ranitidine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution is higher than body volume, and measures at approximately 1.4 L/kg. It concentrates in breast milk, but does not readily distribute into the cerebrospinal fluid. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of ranitidine is approximately 15%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite in the urine is N-oxide, which represents less than 4% of the dose. Other metabolites of ranitidine include S-oxide (1%) and desmethyl ranitidine (1%). The feces contain the remainder of the excreted ranitidine dose. Liver dysfunction has been shown to cause small, but clinically insignificant, changes in various ranitidine pharmacokinetic parameters. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): This drug is mainly excreted in the urine but also excreted in the feces. About 30% of a single oral dose has been measured in the urine as unchanged drug within 24 hours of ingestion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life or ranitidine is about 2.5-3 hours. It may be longer after oral administration versus injection. The plasma half-life is longer for elderly patients population due to a decrease in renal function, and is measured at 3-4 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance is about 410 mL/min according to FDA prescribing information. Another resource mentions a plasma clearance of approximately 600 ml/min. Clearance is decreased in the elderly and those with impaired or hepatic renal function. It is recommended to decrease the dose of ranitidine by one-half in patients with renal impairment. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral doses of 1,000 mg/kg in mice and rats were not found to be lethal. Intravenous LD50 values in mice and rats were 77 and 83 mg/kg, respectively. Overdose information There has been limited experience with ranitidine overdose. Reported acute ingestions of up to 18 grams orally were followed by temporary adverse effects similar to the normal adverse effects of this drug, including tachycardia, bradycardia, dizziness, diarrhea, nausea, and vomiting, among other effects. Gait abnormalities and hypotension have also been observed. When an overdose with ranitidine is suspected, remove unabsorbed ranitidine from the gastrointestinal tract if possible, and monitor the patient and provide supportive therapy as required. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Good Sense Acid Reducer, Wal-zan, Zantac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ranitidine is a histamine H2 antagonist used to treat duodenal ulcers, Zollinger-Ellison syndrome, gastric ulcers, GERD, and erosive esophagitis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Ranolazine interact?

•Drug A: Abatacept •Drug B: Ranolazine •Severity: MODERATE •Description: The metabolism of Ranolazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ranolazine is indicated for the treatment of chronic angina. It can be used alone or in conjunction with nitrates, beta-blockers, angiotensin receptor blockers, anti-platelet drugs, calcium channel blockers, lipid-lowering drugs, and ACE inhibitors. Ranolazine has also been used off-label for the treatment of certain arrhythmias, including ventricular tachycardia, however, this use is not strongly supported by scientific evidence. Ranolazine has also been studied for the treatment of acute coronary syndrome, microvascular coronary dysfunction, arrhythmia, and glycemic control, which are not yet approved indications. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ranolazine exerts both antianginal and ischemic effects independent from lowering heart rate or blood pressure. It blocks IKr, the rapid portion of the delayed rectifier potassium current, and prolongs the QTc interval in a dose-dependent fashion. The Ikr is important for cardiac repolarization. Ranolazine exerts its therapeutic effects without negative chronotropic, dromotropic, or inotropic actions neither at rest, nor during exercise. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Myocardial ischemia exerts effects on adenosine triphosphate flux, leading to a decrease in the energy available for contraction and relaxation of the heart muscle. Electrolyte balance of sodium and potassium is necessary for maintaining normal cardiac contraction and relaxation. Disruption of adequate sodium and potassium electrolyte balance leads to excessively high concentrations of sodium and calcium, which likely interferes with oxygen supply to the heart muscle. This imbalance eventually leads to angina symptoms of chest pain or pressure, nausea, and dizziness, among others. The mechanism of action for ranolazine is not fully understood. At therapeutic concentrations, it can inhibit the cardiac late sodium 205 current (INa), which may affect the electrolyte balance in the myocardium, relieving angina symptoms. The clinical significance this inhibition in the treatment of angina symptoms is not yet confirmed. Ranolazine inhibits sodium and potassium ion channel currents. It has been shown to exert weak activity on L-type calcium channels making it a weak direct vasodilator and exerts minimal direct effects on atrioventricular nodal conduction. Some additional mechanisms have been elucidated. Ranolazine exerts antagonistic activity towards the alpha 1 and beta 1 adrenergic receptors and inhibition of fatty acid oxidation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time to reach peak serum concentration is quite variable but has been observed to be in the range of 2-6 hours, with steady-state within 3 days. The FDA indicates a Tmax of 3-5 hours. The average steady-state Cmax is about 2600 ng/mL. Absorption of ranolazine is not significantly affected by food consumption. The bioavailability of ranolazine taken in the tablet form compared to that from a solution of ranolazine is about 76%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean apparent volume of distribution of ranolazine is reported to be 53.2 L and the average steady-state volume of distribution is estimated to range from 85 to 180 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 62% of the administered dose of ranolazine is bound to plasma proteins. Ranolazine appears to have a higher binding affinity for alpha-1 acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ranolazine is rapidly heavily metabolized in the liver an gastrointestinal tract through the activity of the CYP3A4 enzyme with minor contributions from CYP2D6. More than 40 ranolazine metabolites have been found in plasma and more than 100 metabolites have been identified in the urine. Ranolazine and some of its metabolites are known to weakly inhibit CYP3A4. However, the activity of the metabolites of ranolazine has not been fully elucidated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): From the administered dose, about 3/4 of the dose is excreted renally, while 1/4 of the dose is excreted in the feces. An estimated 5% of an ingested dose is excreted as unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent terminal half-life of ranolazine is 7 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The reported clearance rate of orally administered ranolazine is of 45 L/h when administered at a dose of 500 mg twice daily. The clearance rate of ranolazine is dose-dependent and renal impairment can increase ranolazine serum concentration by 40-50%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The reported LD50 of oral ranolazine in the rat is 980 mg/kg. High oral doses of ranolazine have led to dizziness, nausea, and vomiting. These effects have been shown to be dose related. High intravenous doses can cause diplopia, confusion, paresthesia, in addition to syncope. In the case of an overdose, provide supportive therapy accompanied by continuous ECG monitoring for QT interval prolongation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aspruzyo Sprinkle, Ranexa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ranolazine is an anti-anginal drug used for the treatment of chronic angina.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ranolazine interact? Information: •Drug A: Abatacept •Drug B: Ranolazine •Severity: MODERATE •Description: The metabolism of Ranolazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ranolazine is indicated for the treatment of chronic angina. It can be used alone or in conjunction with nitrates, beta-blockers, angiotensin receptor blockers, anti-platelet drugs, calcium channel blockers, lipid-lowering drugs, and ACE inhibitors. Ranolazine has also been used off-label for the treatment of certain arrhythmias, including ventricular tachycardia, however, this use is not strongly supported by scientific evidence. Ranolazine has also been studied for the treatment of acute coronary syndrome, microvascular coronary dysfunction, arrhythmia, and glycemic control, which are not yet approved indications. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ranolazine exerts both antianginal and ischemic effects independent from lowering heart rate or blood pressure. It blocks IKr, the rapid portion of the delayed rectifier potassium current, and prolongs the QTc interval in a dose-dependent fashion. The Ikr is important for cardiac repolarization. Ranolazine exerts its therapeutic effects without negative chronotropic, dromotropic, or inotropic actions neither at rest, nor during exercise. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Myocardial ischemia exerts effects on adenosine triphosphate flux, leading to a decrease in the energy available for contraction and relaxation of the heart muscle. Electrolyte balance of sodium and potassium is necessary for maintaining normal cardiac contraction and relaxation. Disruption of adequate sodium and potassium electrolyte balance leads to excessively high concentrations of sodium and calcium, which likely interferes with oxygen supply to the heart muscle. This imbalance eventually leads to angina symptoms of chest pain or pressure, nausea, and dizziness, among others. The mechanism of action for ranolazine is not fully understood. At therapeutic concentrations, it can inhibit the cardiac late sodium 205 current (INa), which may affect the electrolyte balance in the myocardium, relieving angina symptoms. The clinical significance this inhibition in the treatment of angina symptoms is not yet confirmed. Ranolazine inhibits sodium and potassium ion channel currents. It has been shown to exert weak activity on L-type calcium channels making it a weak direct vasodilator and exerts minimal direct effects on atrioventricular nodal conduction. Some additional mechanisms have been elucidated. Ranolazine exerts antagonistic activity towards the alpha 1 and beta 1 adrenergic receptors and inhibition of fatty acid oxidation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time to reach peak serum concentration is quite variable but has been observed to be in the range of 2-6 hours, with steady-state within 3 days. The FDA indicates a Tmax of 3-5 hours. The average steady-state Cmax is about 2600 ng/mL. Absorption of ranolazine is not significantly affected by food consumption. The bioavailability of ranolazine taken in the tablet form compared to that from a solution of ranolazine is about 76%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean apparent volume of distribution of ranolazine is reported to be 53.2 L and the average steady-state volume of distribution is estimated to range from 85 to 180 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 62% of the administered dose of ranolazine is bound to plasma proteins. Ranolazine appears to have a higher binding affinity for alpha-1 acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ranolazine is rapidly heavily metabolized in the liver an gastrointestinal tract through the activity of the CYP3A4 enzyme with minor contributions from CYP2D6. More than 40 ranolazine metabolites have been found in plasma and more than 100 metabolites have been identified in the urine. Ranolazine and some of its metabolites are known to weakly inhibit CYP3A4. However, the activity of the metabolites of ranolazine has not been fully elucidated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): From the administered dose, about 3/4 of the dose is excreted renally, while 1/4 of the dose is excreted in the feces. An estimated 5% of an ingested dose is excreted as unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent terminal half-life of ranolazine is 7 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The reported clearance rate of orally administered ranolazine is of 45 L/h when administered at a dose of 500 mg twice daily. The clearance rate of ranolazine is dose-dependent and renal impairment can increase ranolazine serum concentration by 40-50%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The reported LD50 of oral ranolazine in the rat is 980 mg/kg. High oral doses of ranolazine have led to dizziness, nausea, and vomiting. These effects have been shown to be dose related. High intravenous doses can cause diplopia, confusion, paresthesia, in addition to syncope. In the case of an overdose, provide supportive therapy accompanied by continuous ECG monitoring for QT interval prolongation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aspruzyo Sprinkle, Ranexa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ranolazine is an anti-anginal drug used for the treatment of chronic angina. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Rasagiline interact?

•Drug A: Abatacept •Drug B: Rasagiline •Severity: MODERATE •Description: The metabolism of Rasagiline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of the signs and symptoms of idiopathic Parkinsons disease as initial monotherapy and as adjunct therapy to levodopa. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rasagiline is a propargylamine and an irreversible inhibitor of monoamine oxidase (MAO). MAO, a flavin-containing enzyme, regulates the metabolic degradation of catecholamines and serotonin in the CNS and peripheral tissues. It is classified into two major molecular species, A and B, and is localized in mitochondrial membranes throughout the body in nerve terminals, brain, liver and intestinal mucosa. MAO-A is found predominantly in the GI tract and liver, and regulates the metabolic degradation of circulating catecholamines and dietary amines. MAO-B is the major form in the human brain and is responsible for the regulation of the metabolic degradation of dopamine and phenylethylamine. In ex vivo animal studies in brain, liver and intestinal tissues rasagiline was shown to be a potent,selective, and irreversible monoamine oxidase type B (MAO-B) inhibitor. At the recommended therapeutic doses, Rasagiline was also shown to be a potent and irreversible inhibitor of MAO-B in platelets. The selectivity of rasagiline for inhibiting only MAO-B (and not MAO-A) in humans and the sensitivity to tyramine during rasagiline treatment at any dose has not been sufficiently characterized to avoid restriction of dietary tyramine and amines contained in medications. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanisms of action of rasagiline is unknown. One mechanism is believed to be related to its MAO-B inhibitory activity, which causes an increase in extracellular levels of dopamine in the striatum. The elevated dopamine level and subsequent increased dopaminergic activity are likely to mediate rasagiline's beneficial effects seen in models of dopaminergic motor dysfunction. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rasagiline is rapidly absorbed following oral administration. The absolute bioavailability of rasagiline is about 36%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 87 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding ranges from 88-94% with mean extent of binding of 61-63% to human albumin over the concentration range of 1-100 ng/ml. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rasagiline undergoes almost complete biotransformation in the liver prior to excretion. In vitro experiments indicate that both routes of rasagiline metabolism are dependent on the cytochrome P450 (CYP) system, with CYP 1A2 being the major isoenzyme involved in rasagiline metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rasagiline undergoes almost complete biotransformation in the liver prior to excretion. Glucuronide conjugation of rasagiline and its metabolites, with subsequent urinary excretion, is the major elimination pathway. After oral administration of 14C-labeled rasagiline, elimination occurred primarily via urine and secondarily via feces (62% of total dose in urine and 7% of total dose in feces over 7 days), with a total calculated recovery of 84% of the dose over a period of 38 days. Less than 1% of rasagiline was excreted as unchanged drug in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Rasagiline has a mean steady-state half life of 3 hours but there is no correlation of pharmacokinetics with its pharmacological effect because of its irreversible inhibition of MAO-B. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Signs and symptoms of overdosage may include, alone or in combination, any of the following: drowsiness, dizziness, faintness, irritability, hyperactivity, agitation, severe headache, hallucinations, trismus, opisthotonos, convulsions, and coma; rapid and irregular pulse, hypertension, hypotension and vascular collapse; precordial pain, respiratory depression and failure, hyperpyrexia, diaphoresis, and cool, clammy skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azilect •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rasagilina Rasagiline •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rasagiline is an irreversible inhibitor of monoamine oxidase used for the symptomatic management of idiopathic Parkinson's disease as initial monotherapy and as adjunct therapy to levodopa.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rasagiline interact? Information: •Drug A: Abatacept •Drug B: Rasagiline •Severity: MODERATE •Description: The metabolism of Rasagiline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of the signs and symptoms of idiopathic Parkinsons disease as initial monotherapy and as adjunct therapy to levodopa. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rasagiline is a propargylamine and an irreversible inhibitor of monoamine oxidase (MAO). MAO, a flavin-containing enzyme, regulates the metabolic degradation of catecholamines and serotonin in the CNS and peripheral tissues. It is classified into two major molecular species, A and B, and is localized in mitochondrial membranes throughout the body in nerve terminals, brain, liver and intestinal mucosa. MAO-A is found predominantly in the GI tract and liver, and regulates the metabolic degradation of circulating catecholamines and dietary amines. MAO-B is the major form in the human brain and is responsible for the regulation of the metabolic degradation of dopamine and phenylethylamine. In ex vivo animal studies in brain, liver and intestinal tissues rasagiline was shown to be a potent,selective, and irreversible monoamine oxidase type B (MAO-B) inhibitor. At the recommended therapeutic doses, Rasagiline was also shown to be a potent and irreversible inhibitor of MAO-B in platelets. The selectivity of rasagiline for inhibiting only MAO-B (and not MAO-A) in humans and the sensitivity to tyramine during rasagiline treatment at any dose has not been sufficiently characterized to avoid restriction of dietary tyramine and amines contained in medications. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanisms of action of rasagiline is unknown. One mechanism is believed to be related to its MAO-B inhibitory activity, which causes an increase in extracellular levels of dopamine in the striatum. The elevated dopamine level and subsequent increased dopaminergic activity are likely to mediate rasagiline's beneficial effects seen in models of dopaminergic motor dysfunction. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rasagiline is rapidly absorbed following oral administration. The absolute bioavailability of rasagiline is about 36%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 87 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding ranges from 88-94% with mean extent of binding of 61-63% to human albumin over the concentration range of 1-100 ng/ml. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rasagiline undergoes almost complete biotransformation in the liver prior to excretion. In vitro experiments indicate that both routes of rasagiline metabolism are dependent on the cytochrome P450 (CYP) system, with CYP 1A2 being the major isoenzyme involved in rasagiline metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rasagiline undergoes almost complete biotransformation in the liver prior to excretion. Glucuronide conjugation of rasagiline and its metabolites, with subsequent urinary excretion, is the major elimination pathway. After oral administration of 14C-labeled rasagiline, elimination occurred primarily via urine and secondarily via feces (62% of total dose in urine and 7% of total dose in feces over 7 days), with a total calculated recovery of 84% of the dose over a period of 38 days. Less than 1% of rasagiline was excreted as unchanged drug in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Rasagiline has a mean steady-state half life of 3 hours but there is no correlation of pharmacokinetics with its pharmacological effect because of its irreversible inhibition of MAO-B. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Signs and symptoms of overdosage may include, alone or in combination, any of the following: drowsiness, dizziness, faintness, irritability, hyperactivity, agitation, severe headache, hallucinations, trismus, opisthotonos, convulsions, and coma; rapid and irregular pulse, hypertension, hypotension and vascular collapse; precordial pain, respiratory depression and failure, hyperpyrexia, diaphoresis, and cool, clammy skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azilect •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rasagilina Rasagiline •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rasagiline is an irreversible inhibitor of monoamine oxidase used for the symptomatic management of idiopathic Parkinson's disease as initial monotherapy and as adjunct therapy to levodopa. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Ravulizumab interact?

•Drug A: Abatacept •Drug B: Ravulizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ravulizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ravulizumab is indicated for the treatment of adult and pediatric patients one month of age and older with paroxysmal nocturnal hemoglobinuria (PNH). It is also indicated for the treatment of adult and pediatric patients one month of age and older with atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy (TMA). However, the FDA advises against the use of ravulizumab for the treatment of patients with Shiga toxin E. coli related hemolytic uremic syndrome (STEC-HUS). Ravulizumab is also indicated for the treatment of adult patients with generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody-positive. It is indicated for the treatment of adult patients with neuromyelitis optica spectrum disorder (NMOSD) who are anti-aquaporin-4 (AQP4) antibody positive. The European Commission approved ravulizumab for the treatment of paroxysmal nocturnal haemoglobinuria (PNH) in adults and children with a body weight of 10 kg or more with the following conditions: hemolysis with clinical symptoms indicative of high disease activity or clinically stable after having been treated with eculizumab for at least the past six months. Ravulizumab is also indicated for the treatment of hemolytic uremic syndrome (aHUS) in patients with a body weight of 10 kg or more who are either complement inhibitor treatment-naïve or have received eculizumab for at least 3 months and have evidence of response to eculizumab. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ravulizumab is a potent long-acting complement inhibitor of C5, which is a key complement protein involved in inflammatory and thrombotic pathways. It has a long duration of action and fast onset of action. In a clinical study of adult and pediatric patients with paroxysmal nocturnal hemoglobinuria, completion inhibition of free C5 - determined as the serum concentration of less than 0.5 mcg/mL - was observed by the end of the first ravulizumab infusion: this effect was sustained throughout the entire 26-week treatment period. In patients with atypical hemolytic uremic syndrome, inhibition of C5 was observed in 93% of the patients in the study. C5 inhibition by ravulizumab is exposure-dependent. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Complement system activation plays an important role in innate and acquired immunity. Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic stem cell disorder characterized by hemolytic anemia, bone marrow failure, and thrombosis. It is caused by a genetic mutation, leading to complement-mediated hemolysis and deficiencies in glycosylphosphatidylinositol (GPI)-linked proteins such as those involved in fibrinolysis. Atypical hemolytic uraemic syndrome (aHUS) is a type of thrombotic microangiopathy also caused by complement dysregulation. It is associated with thrombocytopenia, microangiopathic hemolytic anemia, and end-organ damage. Myasthenia gravis, an autoimmune neuromuscular disease, also involves the immune system aberrantly attacking the muscles, causing progressive muscle damage. Ravulizumab inhibits the terminal complement pathway by binding to C5 with high affinity: this inhibits the cleavage of C5 to C5a, which is a pro-inflammatory and pro-thrombotic anaphylatoxin, and C5b, an initiating subunit of the terminal complement complex (C5b-9), which promotes cell lysis. Since the generation of C5b is blocked, the formation of C5b-9 is also inhibited by ravulizumab. Ravulizumab inhibits terminal complement-mediated intravascular hemolysis in patients with PNH and complement-mediated thrombotic microangiopathy (TMA) in patients with aHUS. By blocking the complement system, ravulizumab ameliorates the extent of inflammatory and immune responses that play a role in the pathophysiology of myasthenia gravis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In children with paroxysmal nocturnal hemoglobinuria who are complement inhibitor-naïve, the mean C max was 733 mcg/mL following the loading dose and 1490 mcg/mL following the maintenance dose. In children who were previously treated with eculizumab, the mean C max was 885 mcg/mL following the loading dose and 1705 mcg/mL following the maintenance dose. In adults with paroxysmal nocturnal hemoglobinuria who are complement inhibitor-naïve, the mean C max was 771 mcg/mL following the loading dose and 1379 mcg/mL following the maintenance dose. In adults who were previously treated with eculizumab, the mean C max was 843 mcg/mL following the loading dose and 1386 mcg/mL following the maintenance dose. In children with atypical hemolytic uremic syndrome and a body weight of less than 20 kg, the mean C max was 656 mcg/mL following the loading dose and 1467 mcg/mL following the maintenance dose. In children with a body weight ranging from 20 to 40 kg, the mean C max was 600 mcg/mL following the loading dose and 1863 mcg/mL following the maintenance dose. In adults with a body weight greater than 40 kg, the mean C max was 754 mcg/mL following the loading dose and 1458 mcg/mL following the maintenance dose. T max is expected at the end of infusion (EOI) or soon after EOI. Therapeutic steady-state drug concentrations are reached after the first dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (%CV) volume of distribution at steady state was 5.30 (17.9) L in patients with paroxysmal nocturnal hemoglobinuria and 5.22 (35.4) L in patients with atypical hemolytic uremic syndrome. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is no information on the protein binding of ravulizumab. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ravulizumab is expected to be metabolized in the same manner as any endogenous immunoglobulin gamma monoclonal antibody: it undergoes degradation into small peptides and amino acids via catabolic pathways. Ravulizumab contains only natural occurring amino acids and has no known active metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): There is no information on the route of elimination of ravulizumab. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (%CV) terminal elimination half-life of ravulizumab is 49.6 (18.3) days in patients with paroxysmal nocturnal hemoglobinuria and 51.8 (31.3) days in patients with atypical hemolytic uremic syndrome. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean (%CV) clearance of ravulizumab is 0.08 (28.1) L/day in patients with paroxysmal nocturnal hemoglobinuria and 0.08 (53.3) L/day in patients with atypical hemolytic uremic syndrome. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information on the LD 50 value of ravulizumab. No case of ravulizumab overdose has been reported to date. Patients who experience overdose should have immediate interruption of their infusion and be closely monitored. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ultomiris •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ravulizumab is a monoclonal antibody used to treat paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and myasthenia gravis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Ravulizumab interact? Information: •Drug A: Abatacept •Drug B: Ravulizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ravulizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ravulizumab is indicated for the treatment of adult and pediatric patients one month of age and older with paroxysmal nocturnal hemoglobinuria (PNH). It is also indicated for the treatment of adult and pediatric patients one month of age and older with atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy (TMA). However, the FDA advises against the use of ravulizumab for the treatment of patients with Shiga toxin E. coli related hemolytic uremic syndrome (STEC-HUS). Ravulizumab is also indicated for the treatment of adult patients with generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody-positive. It is indicated for the treatment of adult patients with neuromyelitis optica spectrum disorder (NMOSD) who are anti-aquaporin-4 (AQP4) antibody positive. The European Commission approved ravulizumab for the treatment of paroxysmal nocturnal haemoglobinuria (PNH) in adults and children with a body weight of 10 kg or more with the following conditions: hemolysis with clinical symptoms indicative of high disease activity or clinically stable after having been treated with eculizumab for at least the past six months. Ravulizumab is also indicated for the treatment of hemolytic uremic syndrome (aHUS) in patients with a body weight of 10 kg or more who are either complement inhibitor treatment-naïve or have received eculizumab for at least 3 months and have evidence of response to eculizumab. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ravulizumab is a potent long-acting complement inhibitor of C5, which is a key complement protein involved in inflammatory and thrombotic pathways. It has a long duration of action and fast onset of action. In a clinical study of adult and pediatric patients with paroxysmal nocturnal hemoglobinuria, completion inhibition of free C5 - determined as the serum concentration of less than 0.5 mcg/mL - was observed by the end of the first ravulizumab infusion: this effect was sustained throughout the entire 26-week treatment period. In patients with atypical hemolytic uremic syndrome, inhibition of C5 was observed in 93% of the patients in the study. C5 inhibition by ravulizumab is exposure-dependent. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Complement system activation plays an important role in innate and acquired immunity. Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic stem cell disorder characterized by hemolytic anemia, bone marrow failure, and thrombosis. It is caused by a genetic mutation, leading to complement-mediated hemolysis and deficiencies in glycosylphosphatidylinositol (GPI)-linked proteins such as those involved in fibrinolysis. Atypical hemolytic uraemic syndrome (aHUS) is a type of thrombotic microangiopathy also caused by complement dysregulation. It is associated with thrombocytopenia, microangiopathic hemolytic anemia, and end-organ damage. Myasthenia gravis, an autoimmune neuromuscular disease, also involves the immune system aberrantly attacking the muscles, causing progressive muscle damage. Ravulizumab inhibits the terminal complement pathway by binding to C5 with high affinity: this inhibits the cleavage of C5 to C5a, which is a pro-inflammatory and pro-thrombotic anaphylatoxin, and C5b, an initiating subunit of the terminal complement complex (C5b-9), which promotes cell lysis. Since the generation of C5b is blocked, the formation of C5b-9 is also inhibited by ravulizumab. Ravulizumab inhibits terminal complement-mediated intravascular hemolysis in patients with PNH and complement-mediated thrombotic microangiopathy (TMA) in patients with aHUS. By blocking the complement system, ravulizumab ameliorates the extent of inflammatory and immune responses that play a role in the pathophysiology of myasthenia gravis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In children with paroxysmal nocturnal hemoglobinuria who are complement inhibitor-naïve, the mean C max was 733 mcg/mL following the loading dose and 1490 mcg/mL following the maintenance dose. In children who were previously treated with eculizumab, the mean C max was 885 mcg/mL following the loading dose and 1705 mcg/mL following the maintenance dose. In adults with paroxysmal nocturnal hemoglobinuria who are complement inhibitor-naïve, the mean C max was 771 mcg/mL following the loading dose and 1379 mcg/mL following the maintenance dose. In adults who were previously treated with eculizumab, the mean C max was 843 mcg/mL following the loading dose and 1386 mcg/mL following the maintenance dose. In children with atypical hemolytic uremic syndrome and a body weight of less than 20 kg, the mean C max was 656 mcg/mL following the loading dose and 1467 mcg/mL following the maintenance dose. In children with a body weight ranging from 20 to 40 kg, the mean C max was 600 mcg/mL following the loading dose and 1863 mcg/mL following the maintenance dose. In adults with a body weight greater than 40 kg, the mean C max was 754 mcg/mL following the loading dose and 1458 mcg/mL following the maintenance dose. T max is expected at the end of infusion (EOI) or soon after EOI. Therapeutic steady-state drug concentrations are reached after the first dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (%CV) volume of distribution at steady state was 5.30 (17.9) L in patients with paroxysmal nocturnal hemoglobinuria and 5.22 (35.4) L in patients with atypical hemolytic uremic syndrome. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is no information on the protein binding of ravulizumab. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ravulizumab is expected to be metabolized in the same manner as any endogenous immunoglobulin gamma monoclonal antibody: it undergoes degradation into small peptides and amino acids via catabolic pathways. Ravulizumab contains only natural occurring amino acids and has no known active metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): There is no information on the route of elimination of ravulizumab. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (%CV) terminal elimination half-life of ravulizumab is 49.6 (18.3) days in patients with paroxysmal nocturnal hemoglobinuria and 51.8 (31.3) days in patients with atypical hemolytic uremic syndrome. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean (%CV) clearance of ravulizumab is 0.08 (28.1) L/day in patients with paroxysmal nocturnal hemoglobinuria and 0.08 (53.3) L/day in patients with atypical hemolytic uremic syndrome. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information on the LD 50 value of ravulizumab. No case of ravulizumab overdose has been reported to date. Patients who experience overdose should have immediate interruption of their infusion and be closely monitored. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ultomiris •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ravulizumab is a monoclonal antibody used to treat paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, and myasthenia gravis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Regorafenib interact?

•Drug A: Abatacept •Drug B: Regorafenib •Severity: MAJOR •Description: The metabolism of Regorafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Regorafenib is indicated for the treatment of patients with metastatic colorectal cancer (CRC) who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF therapy, and, if KRAS wild type, an anti-EGFR therapy. Regorafenib is also indicated for the treatment of patients with locally advanced, unresectable or metastatic gastrointestinal stromal tumour (GIST) who have been previously treated with imatinib mesylate and sunitinib malate. Regorafenib is also indicated for the treatment of patients with hepatocellular carcinoma (HCC) previously treated with sorafenib. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Regorafenib is a small molecule inhibitor of multiple membrane-bound and intracellular kinases involved in normal cellular functions and in pathologic processes such as oncogenesis, tumor angiogenesis, and maintenance of the tumor microenvironment. In in vitro biochemical or cellular assays, regorafenib or its major human active metabolites M-2 and M-5 inhibited the activity of RET, VEGFR1, VEGFR2, VEGFR3, KIT, PDGFR-alpha, PDGFR-beta, FGFR1, FGFR2, TIE2, DDR2, TrkA, Eph2A, RAF-1, BRAF, BRAFV600E, SAPK2, PTK5, and Abl at concentrations of regorafenib that have been achieved clinically. In in vivo models, regorafenib demonstrated anti-angiogenic activity in a rat tumor model, and inhibition of tumor growth as well as anti-metastatic activity in several mouse xenograft models including some for human colorectal carcinoma. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cmax = 2.5 μg/mL; Tmax = 4 hours; AUC = 70.4 μg h/mL; Cmax, steady-state = 3.9 μg/mL; AUC, steady-state = 58.3 μg h/mL; The mean relative bioavailability of tablets compared to an oral solution is 69% to 83%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Regorafenib undergoes enterohepatic circulation with multiple plasma concentration peaks observed across the 24-hour dosing interval. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Regorafenib is highly bound (99.5%) to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Regorafenib is metabolized by CYP3A4 and UGT1A9. The main circulating metabolites of regorafenib measured at steady-state in human plasma are M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl), both of them having similar in vitro pharmacological activity and steady-state concentrations as regorafenib. M-2 and M-5 are highly protein bound (99.8% and 99.95%, respectively). Regorafenib is an inhibitor of P-glycoprotein, while its active metabolites M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl) are substrates of P-glycoprotein. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 71% of a radiolabeled dose was excreted in feces (47% as parent compound, 24% as metabolites) and 19% of the dose was excreted in urine (17% as glucuronides) within 12 days after administration of a radiolabeled oral solution at a dose of 120 mg. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Regorafenib, 160 mg oral dose = 28 hours (14 - 58 hours); M2 metabolite, 160 mg oral dose = 25 hours (14-32 hours); M5 metabolite, 160 mg oral dose = 51 hours (32-72 hours); •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse reactions (≥20%) are asthenia/fatigue, HFSR, diarrhea, decreased appetite/food intake, hypertension, mucositis, dysphonia, and infection, pain (not otherwise specified), decreased weight, gastrointestinal and abdominal pain, rash, fever, and nausea •Brand Names (Drug A): Orencia •Brand Names (Drug B): Stivarga •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Regorafenib is a kinase inhibitor used to treat patients with metastatic colorectal cancer, unresectable, locally advanced, or metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Regorafenib interact? Information: •Drug A: Abatacept •Drug B: Regorafenib •Severity: MAJOR •Description: The metabolism of Regorafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Regorafenib is indicated for the treatment of patients with metastatic colorectal cancer (CRC) who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF therapy, and, if KRAS wild type, an anti-EGFR therapy. Regorafenib is also indicated for the treatment of patients with locally advanced, unresectable or metastatic gastrointestinal stromal tumour (GIST) who have been previously treated with imatinib mesylate and sunitinib malate. Regorafenib is also indicated for the treatment of patients with hepatocellular carcinoma (HCC) previously treated with sorafenib. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Regorafenib is a small molecule inhibitor of multiple membrane-bound and intracellular kinases involved in normal cellular functions and in pathologic processes such as oncogenesis, tumor angiogenesis, and maintenance of the tumor microenvironment. In in vitro biochemical or cellular assays, regorafenib or its major human active metabolites M-2 and M-5 inhibited the activity of RET, VEGFR1, VEGFR2, VEGFR3, KIT, PDGFR-alpha, PDGFR-beta, FGFR1, FGFR2, TIE2, DDR2, TrkA, Eph2A, RAF-1, BRAF, BRAFV600E, SAPK2, PTK5, and Abl at concentrations of regorafenib that have been achieved clinically. In in vivo models, regorafenib demonstrated anti-angiogenic activity in a rat tumor model, and inhibition of tumor growth as well as anti-metastatic activity in several mouse xenograft models including some for human colorectal carcinoma. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cmax = 2.5 μg/mL; Tmax = 4 hours; AUC = 70.4 μg h/mL; Cmax, steady-state = 3.9 μg/mL; AUC, steady-state = 58.3 μg h/mL; The mean relative bioavailability of tablets compared to an oral solution is 69% to 83%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Regorafenib undergoes enterohepatic circulation with multiple plasma concentration peaks observed across the 24-hour dosing interval. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Regorafenib is highly bound (99.5%) to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Regorafenib is metabolized by CYP3A4 and UGT1A9. The main circulating metabolites of regorafenib measured at steady-state in human plasma are M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl), both of them having similar in vitro pharmacological activity and steady-state concentrations as regorafenib. M-2 and M-5 are highly protein bound (99.8% and 99.95%, respectively). Regorafenib is an inhibitor of P-glycoprotein, while its active metabolites M-2 (N-oxide) and M-5 (N-oxide and N-desmethyl) are substrates of P-glycoprotein. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 71% of a radiolabeled dose was excreted in feces (47% as parent compound, 24% as metabolites) and 19% of the dose was excreted in urine (17% as glucuronides) within 12 days after administration of a radiolabeled oral solution at a dose of 120 mg. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Regorafenib, 160 mg oral dose = 28 hours (14 - 58 hours); M2 metabolite, 160 mg oral dose = 25 hours (14-32 hours); M5 metabolite, 160 mg oral dose = 51 hours (32-72 hours); •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse reactions (≥20%) are asthenia/fatigue, HFSR, diarrhea, decreased appetite/food intake, hypertension, mucositis, dysphonia, and infection, pain (not otherwise specified), decreased weight, gastrointestinal and abdominal pain, rash, fever, and nausea •Brand Names (Drug A): Orencia •Brand Names (Drug B): Stivarga •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Regorafenib is a kinase inhibitor used to treat patients with metastatic colorectal cancer, unresectable, locally advanced, or metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Relugolix interact?

•Drug A: Abatacept •Drug B: Relugolix •Severity: MODERATE •Description: The metabolism of Relugolix can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Relugolix is indicated for the treatment of adult patients with advanced prostate cancer. In a combination product with estradiol and norethindrone, relugolix is indicated for the once-daily treatment for the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Approximately 56% of patients achieved castrate-level testosterone concentrations (<50 ng/dL) by day 4 of therapy and 97% of patients maintain these levels through 48 weeks of therapy. Relugolix requires once-daily oral administration to maintain the desired testosterone concentrations. Androgen deprivation therapies may prolong the QTc interval and should therefore be used with caution in patients having a high baseline risk of QTc prolongation, such as those with electrolyte abnormalities, congestive heart failure, or using other medications known to prolong the QTc interval. Based on its mechanism of action and data from animal studies, relugolix may result in fetal harm if administered to pregnant females - male patients with female partners should be advised to use effective contraception throughout therapy and for 2 weeks following cessation of therapy to prevent inadvertent fetal exposure. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The pathogenesis and progression of prostate cancer appear driven, at least in part, by the effects of testosterone. Androgen deprivation has been demonstrated to result in cell death and tumor regression in many well-differentiated prostate cancer cell lines - for this reason, androgen deprivation therapy (ADT) has become a standard in the treatment of prostate cancer, particularly in advanced disease. Testosterone production in males is carried out in the Leydig cells of testes and is stimulated by luteinizing hormone (LH), which itself is produced in the pituitary gland following the binding of gonadotropin-releasing hormone (GnRH) to corresponding GnRH receptors. Relugolix is a competitive antagonist of these GnRH receptors, thereby decreasing the release of LH and, ultimately, testosterone. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC of orally-administered relugolix increase proportionally following single doses - in contrast, with repeat dosing the AUC remains proportional to the dose while the C max increases greater than proportionally to the dose. Following the administration of 120mg once daily, the steady-state AUC and C max of relugolix were 407 (± 168) ng.hr/mL and 70 (± 65) ng/mL, respectively. The absolute oral bioavailability of relugolix is approximately 12% and the median T max following oral administration is 2.25 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Relugolix is 68-71% protein-bound in plasma, primarily to albumin and, to a lesser extent, α1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Relugolix is metabolized mainly by the CYP3A subfamily of P450 enzymes, with a smaller contribution by CYP2C8. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 81% of an orally administered dose was recovered in the feces, of which 4.2% was unchanged parent drug, while 4.1% of the dose was recovered in the urine, of which 2.2% remained unchanged. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The average effective half-life of relugolix is 25 hours, while the average terminal elimination half-life is 60.8 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The average renal clearance of relugolix is 8 L/h with a total clearance of 26.4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding overdose of relugolix are unavailable. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Myfembree, Orgovyx •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Relugolix is an oral GnRH receptor antagonist for androgen deprivation therapy in the treatment of advanced prostate cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Relugolix interact? Information: •Drug A: Abatacept •Drug B: Relugolix •Severity: MODERATE •Description: The metabolism of Relugolix can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Relugolix is indicated for the treatment of adult patients with advanced prostate cancer. In a combination product with estradiol and norethindrone, relugolix is indicated for the once-daily treatment for the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Approximately 56% of patients achieved castrate-level testosterone concentrations (<50 ng/dL) by day 4 of therapy and 97% of patients maintain these levels through 48 weeks of therapy. Relugolix requires once-daily oral administration to maintain the desired testosterone concentrations. Androgen deprivation therapies may prolong the QTc interval and should therefore be used with caution in patients having a high baseline risk of QTc prolongation, such as those with electrolyte abnormalities, congestive heart failure, or using other medications known to prolong the QTc interval. Based on its mechanism of action and data from animal studies, relugolix may result in fetal harm if administered to pregnant females - male patients with female partners should be advised to use effective contraception throughout therapy and for 2 weeks following cessation of therapy to prevent inadvertent fetal exposure. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The pathogenesis and progression of prostate cancer appear driven, at least in part, by the effects of testosterone. Androgen deprivation has been demonstrated to result in cell death and tumor regression in many well-differentiated prostate cancer cell lines - for this reason, androgen deprivation therapy (ADT) has become a standard in the treatment of prostate cancer, particularly in advanced disease. Testosterone production in males is carried out in the Leydig cells of testes and is stimulated by luteinizing hormone (LH), which itself is produced in the pituitary gland following the binding of gonadotropin-releasing hormone (GnRH) to corresponding GnRH receptors. Relugolix is a competitive antagonist of these GnRH receptors, thereby decreasing the release of LH and, ultimately, testosterone. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC of orally-administered relugolix increase proportionally following single doses - in contrast, with repeat dosing the AUC remains proportional to the dose while the C max increases greater than proportionally to the dose. Following the administration of 120mg once daily, the steady-state AUC and C max of relugolix were 407 (± 168) ng.hr/mL and 70 (± 65) ng/mL, respectively. The absolute oral bioavailability of relugolix is approximately 12% and the median T max following oral administration is 2.25 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Relugolix is 68-71% protein-bound in plasma, primarily to albumin and, to a lesser extent, α1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Relugolix is metabolized mainly by the CYP3A subfamily of P450 enzymes, with a smaller contribution by CYP2C8. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 81% of an orally administered dose was recovered in the feces, of which 4.2% was unchanged parent drug, while 4.1% of the dose was recovered in the urine, of which 2.2% remained unchanged. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The average effective half-life of relugolix is 25 hours, while the average terminal elimination half-life is 60.8 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The average renal clearance of relugolix is 8 L/h with a total clearance of 26.4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding overdose of relugolix are unavailable. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Myfembree, Orgovyx •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Relugolix is an oral GnRH receptor antagonist for androgen deprivation therapy in the treatment of advanced prostate cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Repaglinide interact?

•Drug A: Abatacept •Drug B: Repaglinide •Severity: MODERATE •Description: The metabolism of Repaglinide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): As an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Insulin secretion by pancreatic β cells is partly controlled by cellular membrane potential. Membrane potential is regulated through an inverse relationship between the activity of cell membrane ATP-sensitive potassium channels (ABCC8) and extracellular glucose concentrations. Extracellular glucose enters the cell via GLUT2 (SLC2A2) transporters. Once inside the cell, glucose is metabolized to produce ATP. High concentrations of ATP inhibit ATP-sensitive potassium channels causing membrane depolarization. When extracellular glucose concentrations are low, ATP-sensitive potassium channels open causing membrane repolarization. High glucose concentrations cause ATP-sensitive potassium channels to close resulting in membrane depolarization and opening of L-type calcium channels. The influx of calcium ions stimulates calcium-dependent exocytosis of insulin granules. Repaglinide increases insulin release by inhibiting ATP-sensitive potassium channels in a glucose-dependent manner. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Repaglinide activity is dependent on the presence functioning β cells and glucose. In contrast to sulfonylurea insulin secretatogogues, repaglinide has no effect on insulin release in the absence of glucose. Rather, it potentiates the effect of extracellular glucose on ATP-sensitive potassium channel and has little effect on insulin levels between meals and overnight. As such, repaglinide is more effective at reducing postprandial blood glucose levels than fasting blood glucose levels and requires a longer duration of therapy (approximately one month) before decreases in fasting blood glucose are observed. The insulinotropic effects of repaglinide are highest at intermediate glucose levels (3 to 10 mmol/L) and it does not increase insulin release already stimulated by high glucose concentrations (greater than 15 mmol/L). Repaglinide appears to be selective for pancreatic β cells and does not appear to affect skeletal or cardiac muscle or thyroid tissue. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly and completely absorbed following oral administration. Peak plasma concentrations are observed within 1 hour (range 0.5-1.4 hours). The absolute bioavailability is approximately 56%. Maximal biological effect is observed within 3-3.5 hours and plasma insulin levels remain elevated for 4-6 hours. When a single 2 mg dose of repaglinide is given to healthy subjects, the area under the curve (AUC) is 18.0 - 18.7 (ng/mL/h)^3. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 31 L following IV administration in healthy individuals •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >98% (e.g. to to albumin and α1-acid glycoprotein) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Repaglinide is rapidly metabolized via oxidation and dealkylation by cytochrome P450 3A4 and 2C9 to form the major dicarboxylic acid derivative (M2). Further oxidation produces the aromatic amine derivative (M1). Glucuronidation of the carboxylic acid group of repaglinide yields an acyl glucuronide (M7). Several other unidentified metabolites have been detected. Repaglinide metabolites to not possess appreciable hypoglycemic activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 90% eliminated in feces (<2% as unchanged drug), 8% in urine (0.1% as unchanged drug) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1 hour •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 33-38 L/hour following IV administration •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 >1 g/kg (rat) (W. Grell) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enyglid, Gluconorm, Prandin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Repaglinide is a antihyperglycemic used to improve glycemic control in diabetes.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Repaglinide interact? Information: •Drug A: Abatacept •Drug B: Repaglinide •Severity: MODERATE •Description: The metabolism of Repaglinide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): As an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Insulin secretion by pancreatic β cells is partly controlled by cellular membrane potential. Membrane potential is regulated through an inverse relationship between the activity of cell membrane ATP-sensitive potassium channels (ABCC8) and extracellular glucose concentrations. Extracellular glucose enters the cell via GLUT2 (SLC2A2) transporters. Once inside the cell, glucose is metabolized to produce ATP. High concentrations of ATP inhibit ATP-sensitive potassium channels causing membrane depolarization. When extracellular glucose concentrations are low, ATP-sensitive potassium channels open causing membrane repolarization. High glucose concentrations cause ATP-sensitive potassium channels to close resulting in membrane depolarization and opening of L-type calcium channels. The influx of calcium ions stimulates calcium-dependent exocytosis of insulin granules. Repaglinide increases insulin release by inhibiting ATP-sensitive potassium channels in a glucose-dependent manner. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Repaglinide activity is dependent on the presence functioning β cells and glucose. In contrast to sulfonylurea insulin secretatogogues, repaglinide has no effect on insulin release in the absence of glucose. Rather, it potentiates the effect of extracellular glucose on ATP-sensitive potassium channel and has little effect on insulin levels between meals and overnight. As such, repaglinide is more effective at reducing postprandial blood glucose levels than fasting blood glucose levels and requires a longer duration of therapy (approximately one month) before decreases in fasting blood glucose are observed. The insulinotropic effects of repaglinide are highest at intermediate glucose levels (3 to 10 mmol/L) and it does not increase insulin release already stimulated by high glucose concentrations (greater than 15 mmol/L). Repaglinide appears to be selective for pancreatic β cells and does not appear to affect skeletal or cardiac muscle or thyroid tissue. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly and completely absorbed following oral administration. Peak plasma concentrations are observed within 1 hour (range 0.5-1.4 hours). The absolute bioavailability is approximately 56%. Maximal biological effect is observed within 3-3.5 hours and plasma insulin levels remain elevated for 4-6 hours. When a single 2 mg dose of repaglinide is given to healthy subjects, the area under the curve (AUC) is 18.0 - 18.7 (ng/mL/h)^3. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 31 L following IV administration in healthy individuals •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >98% (e.g. to to albumin and α1-acid glycoprotein) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Repaglinide is rapidly metabolized via oxidation and dealkylation by cytochrome P450 3A4 and 2C9 to form the major dicarboxylic acid derivative (M2). Further oxidation produces the aromatic amine derivative (M1). Glucuronidation of the carboxylic acid group of repaglinide yields an acyl glucuronide (M7). Several other unidentified metabolites have been detected. Repaglinide metabolites to not possess appreciable hypoglycemic activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 90% eliminated in feces (<2% as unchanged drug), 8% in urine (0.1% as unchanged drug) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1 hour •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 33-38 L/hour following IV administration •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 >1 g/kg (rat) (W. Grell) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enyglid, Gluconorm, Prandin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Repaglinide is a antihyperglycemic used to improve glycemic control in diabetes. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Resmetirom interact?

•Drug A: Abatacept •Drug B: Resmetirom •Severity: MODERATE •Description: The metabolism of Resmetirom can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Resmetirom is indicated in conjunction with diet and exercise for the treatment of adults with noncirrhotic nonalcoholic steatohepatitis (NASH) with moderate to advanced liver fibrosis (consistent with stages F2 to F3 fibrosis). Its use should be avoided in patients with decompensated cirrhosis. This indication is approved under accelerated approval based on the improvement of NASH and fibrosis. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Resmetirom is a partial agonist of the thyroid hormone receptor-beta (THR-β). Resmetirom produced 83.8% of the maximum response compared to triiodothyronine (T3), with an EC 50 of 0.21 µM in an in vitro functional assay for THR-β activation. The same functional assay for thyroid hormone receptor-alpha (THR-α) agonism showed 48.6% efficacy for resmetirom relative to T3, with an EC50 of 3.74 µM. Resmetirom decreases liver fat content and the concentrations of free thyroxine (FT4), which is a prohormone. Although it is inconclusive, there have been some reports in the literature suggesting that resmetirom may convert thyroxine (T4) to triiodothyronine (T3). It increases the concentrations of sex hormone-binding globulin. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Thyroid hormones, such as FT4 and free triiodothyronine (FT3), are key regulators of lipid metabolism in the liver. Thyroid hormone receptor-beta (THR-β) is the major form of the thyroid hormone receptor in the liver, and stimulation of this receptor reduces intrahepatic triglycerides. Many patients with non-alcoholic fatty liver disease (NAFLD) present with impaired thyroid function, such as hypothyroidism, rendering it a significant risk factor for NAFLD. Hypothyroidism has also been linked to dysregulated adipose tissue lipolysis and increased free fatty acid release from the adipose to the liver, promoting hepatic insulin resistance. Increased circulating levels of proinflammatory adipokines, which contribute to hepatic inflammation and fibrosis, may also be observed. Resmetirom is a partial agonist of THR-β that promotes lipophagy and hepatic fatty acid β-oxidation, thereby reducing liver fat. It is approximately 28 times more selective than FT3 for THR-β versus thyroid hormone receptor-alpha (THR-α), which is mainly expressed in the heart and bones. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The median T max is approximately four hours following multiple daily doses of resmetirom 80 mg or 100 mg. Concomitant food administration resulted in a 33% decrease in C max, an 11% decrease in AUC, and a delay in median T max by about two hours compared to an under-fasted condition. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Resmetirom apparent volume of distribution (Vd/F) at steady-state is 68 (227%) L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Resmetirom is greater than 99% protein-bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Resmetirom is metabolized by CYP2C8. MGL-3623 is a major metabolite with a 28-times lower potency for THR-β than resmetirom. MGL-3623 represents 33% to 51% of resmetirom AUC at steady-state following administration of 100 mg once daily. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a 100 mg radio-labeled dose of resmetirom, approximately 67% of the total radioactive dose was recovered in the feces, mostly as metabolites and 24% of the total radioactive dose was recovered in the urine. Unchanged labeled resmetirom was not detected in feces and accounted for 1% of the dose recovered in urine. A metabolite MGL-3623 accounted for 3.3% and 16% of the dose recovered in feces and urine, respectively. Oxalic acid metabolite was observed in plasma but not in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The median terminal plasma half-life is 4.5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The steady state apparent clearance (CL/F) is 17.5 (56.3%) L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information regarding the acute toxicity and overdosage of resmetirom. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Resmetirom is a thyroid hormone receptor-beta agonist used to treat noncirrhotic nonalcoholic steatohepatitis (NASH) with moderate to advanced liver fibrosis in adults.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Resmetirom interact? Information: •Drug A: Abatacept •Drug B: Resmetirom •Severity: MODERATE •Description: The metabolism of Resmetirom can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Resmetirom is indicated in conjunction with diet and exercise for the treatment of adults with noncirrhotic nonalcoholic steatohepatitis (NASH) with moderate to advanced liver fibrosis (consistent with stages F2 to F3 fibrosis). Its use should be avoided in patients with decompensated cirrhosis. This indication is approved under accelerated approval based on the improvement of NASH and fibrosis. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Resmetirom is a partial agonist of the thyroid hormone receptor-beta (THR-β). Resmetirom produced 83.8% of the maximum response compared to triiodothyronine (T3), with an EC 50 of 0.21 µM in an in vitro functional assay for THR-β activation. The same functional assay for thyroid hormone receptor-alpha (THR-α) agonism showed 48.6% efficacy for resmetirom relative to T3, with an EC50 of 3.74 µM. Resmetirom decreases liver fat content and the concentrations of free thyroxine (FT4), which is a prohormone. Although it is inconclusive, there have been some reports in the literature suggesting that resmetirom may convert thyroxine (T4) to triiodothyronine (T3). It increases the concentrations of sex hormone-binding globulin. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Thyroid hormones, such as FT4 and free triiodothyronine (FT3), are key regulators of lipid metabolism in the liver. Thyroid hormone receptor-beta (THR-β) is the major form of the thyroid hormone receptor in the liver, and stimulation of this receptor reduces intrahepatic triglycerides. Many patients with non-alcoholic fatty liver disease (NAFLD) present with impaired thyroid function, such as hypothyroidism, rendering it a significant risk factor for NAFLD. Hypothyroidism has also been linked to dysregulated adipose tissue lipolysis and increased free fatty acid release from the adipose to the liver, promoting hepatic insulin resistance. Increased circulating levels of proinflammatory adipokines, which contribute to hepatic inflammation and fibrosis, may also be observed. Resmetirom is a partial agonist of THR-β that promotes lipophagy and hepatic fatty acid β-oxidation, thereby reducing liver fat. It is approximately 28 times more selective than FT3 for THR-β versus thyroid hormone receptor-alpha (THR-α), which is mainly expressed in the heart and bones. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The median T max is approximately four hours following multiple daily doses of resmetirom 80 mg or 100 mg. Concomitant food administration resulted in a 33% decrease in C max, an 11% decrease in AUC, and a delay in median T max by about two hours compared to an under-fasted condition. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Resmetirom apparent volume of distribution (Vd/F) at steady-state is 68 (227%) L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Resmetirom is greater than 99% protein-bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Resmetirom is metabolized by CYP2C8. MGL-3623 is a major metabolite with a 28-times lower potency for THR-β than resmetirom. MGL-3623 represents 33% to 51% of resmetirom AUC at steady-state following administration of 100 mg once daily. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a 100 mg radio-labeled dose of resmetirom, approximately 67% of the total radioactive dose was recovered in the feces, mostly as metabolites and 24% of the total radioactive dose was recovered in the urine. Unchanged labeled resmetirom was not detected in feces and accounted for 1% of the dose recovered in urine. A metabolite MGL-3623 accounted for 3.3% and 16% of the dose recovered in feces and urine, respectively. Oxalic acid metabolite was observed in plasma but not in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The median terminal plasma half-life is 4.5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The steady state apparent clearance (CL/F) is 17.5 (56.3%) L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information regarding the acute toxicity and overdosage of resmetirom. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Resmetirom is a thyroid hormone receptor-beta agonist used to treat noncirrhotic nonalcoholic steatohepatitis (NASH) with moderate to advanced liver fibrosis in adults. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Respiratory syncytial virus vaccine, adjuvanted interact?

•Drug A: Abatacept •Drug B: Respiratory syncytial virus vaccine, adjuvanted •Severity: MODERATE •Description: The therapeutic efficacy of GSK-3844766A can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Respiratory syncytial virus vaccine, adjuvanted interact? Information: •Drug A: Abatacept •Drug B: Respiratory syncytial virus vaccine, adjuvanted •Severity: MODERATE •Description: The therapeutic efficacy of GSK-3844766A can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Revefenacin interact?

•Drug A: Abatacept •Drug B: Revefenacin •Severity: MODERATE •Description: The metabolism of Revefenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Revefenacin is indicated as an inhalation solution for the maintenance treatment of patients with chronic obstructive pulmonary disease (COPD). COPD is a growing disease being the third leading cause of death in the US. This disease is characterized by not fully reversible airflow limitation. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Revefenacin has been reported to produce a sustained, long-acting bronchodilation with lower anti-muscarinic-related side effects. In clinical trials, revefenacin demonstrated to be of a long duration of action and low systemic exposure in patients with COPD. Also, it was reported that a dose of 88 mcg can produce a clinically effective bronchodilation measured by through forced expiratory volume in 1s and serial spirometric assessments. In placebo-controlled trials, revefenacin showed a decrease in the use of albuterol rescue inhalers and sustained increases in the peak expiratory flow rate that reached a steady state at a maximum in day 7. As well, there was a reported superior lung selectivity index when compared with other LAMAs such as glycopyrronium and tiotropium which produced a decreased sialagogue effect. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Revefenacin is an inhaled bronchodilator muscarinic antagonist with a long-acting bronchodilation activity. It has been shown to present a high affinity and behaved as a competitive antagonist of the five muscarinic cholinergic receptors. Studies have indicated that revefenacin dissociates significantly slower from the muscarinic receptor M3 (hM3) when compared to the receptor M2 (hM2) which indicates a kinetic selectivity for this subtype. This competitive antagonism produces a suppressive action of the acetylcholine-evoked calcium mobilization and contractile responses in the airway tissue. Lastly, due to the duration of the bronchodilation, revefenacin is considered a long-acting muscarinic antagonist which allows it to be dosed once daily. This response is very important for the therapy of COPD as the main goal is the reduce the frequency and severity of exacerbations which are normally driven by the presence of elevated cholinergic bronchoconstrictor tone mediated by muscarinic receptors on parasympathetic ganglia and airway smooth muscle. Hence, the activity of revefenacin produces a potent and long-lasting protection against the bronchoconstrictor response to acetylcholine or methacholine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In pharmacokinetic studies, revefenacin was absorbed very rapidly and presented a linear increase in plasma exposure with Cmax, tmax and AUC that ranged between 0.02-0.15 ng/ml, 0.48-0.51 hours and 0.03-0.36 ng.h/ml, respectively. The bioaccumulation of revefenacin was very limited and the steady-state was achieved by day 7. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): After intravenous administration of revefenacin, the reported volume of distribution is 218 L which suggests an extensive distribution to the tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of revefenacin and its active metabolite is of 71% and 42% respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Revefenacin presents a high metabolic liability producing a rapid metabolic turnover after being distributed from the lung. This metabolic process is done primarily via enzymatic hydrolysis via CYP2D6 to its major hydrolytic metabolite THRX-195518. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After reaching maximum concentration, revefenacin concentrations decline in a biphasic manner. This elimination kinetics is observed by a rapid declining plasma concentration followed by a slow apparent bi-exponential elimination. Renal elimination of revefenacin is limited and it presents a mean cumulative amount excreted in urine as the unchanged drug of < 0.2% of the administered dose. Following intravenous revefenacin administration, 54% of the dose is recovered in feces and 27% was recovered in urine which confirms a high hepatobiliary processing. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent terminal half-life of a dose of 350 mcg of revefenacin was 22.3-70 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The renal clearance of revefenacin is negligible and thus, the clearance rate is not a major parameter for this drug. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Revefenacin does not produce the typical systemic effects associated with anticholinergic therapies. In carcinogenic studies in animals, there was no evidence of tumorigenicity. As well, there was no evidence of mutagenicity in the Ames test nor genotoxicity in in vitro mouse lymphoma assays and in vivo rat bone marrow micronucleus assays. There is no effect in the fertility. In overdose situations, the common signs and symptoms are nausea, vomiting, dizziness, lightheadedness, blurred vision, increased intraocular pressure, obstipation and difficulties in voiding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Revefenacin is an anticholinergic agent used to treat COPD.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Revefenacin interact? Information: •Drug A: Abatacept •Drug B: Revefenacin •Severity: MODERATE •Description: The metabolism of Revefenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Revefenacin is indicated as an inhalation solution for the maintenance treatment of patients with chronic obstructive pulmonary disease (COPD). COPD is a growing disease being the third leading cause of death in the US. This disease is characterized by not fully reversible airflow limitation. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Revefenacin has been reported to produce a sustained, long-acting bronchodilation with lower anti-muscarinic-related side effects. In clinical trials, revefenacin demonstrated to be of a long duration of action and low systemic exposure in patients with COPD. Also, it was reported that a dose of 88 mcg can produce a clinically effective bronchodilation measured by through forced expiratory volume in 1s and serial spirometric assessments. In placebo-controlled trials, revefenacin showed a decrease in the use of albuterol rescue inhalers and sustained increases in the peak expiratory flow rate that reached a steady state at a maximum in day 7. As well, there was a reported superior lung selectivity index when compared with other LAMAs such as glycopyrronium and tiotropium which produced a decreased sialagogue effect. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Revefenacin is an inhaled bronchodilator muscarinic antagonist with a long-acting bronchodilation activity. It has been shown to present a high affinity and behaved as a competitive antagonist of the five muscarinic cholinergic receptors. Studies have indicated that revefenacin dissociates significantly slower from the muscarinic receptor M3 (hM3) when compared to the receptor M2 (hM2) which indicates a kinetic selectivity for this subtype. This competitive antagonism produces a suppressive action of the acetylcholine-evoked calcium mobilization and contractile responses in the airway tissue. Lastly, due to the duration of the bronchodilation, revefenacin is considered a long-acting muscarinic antagonist which allows it to be dosed once daily. This response is very important for the therapy of COPD as the main goal is the reduce the frequency and severity of exacerbations which are normally driven by the presence of elevated cholinergic bronchoconstrictor tone mediated by muscarinic receptors on parasympathetic ganglia and airway smooth muscle. Hence, the activity of revefenacin produces a potent and long-lasting protection against the bronchoconstrictor response to acetylcholine or methacholine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In pharmacokinetic studies, revefenacin was absorbed very rapidly and presented a linear increase in plasma exposure with Cmax, tmax and AUC that ranged between 0.02-0.15 ng/ml, 0.48-0.51 hours and 0.03-0.36 ng.h/ml, respectively. The bioaccumulation of revefenacin was very limited and the steady-state was achieved by day 7. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): After intravenous administration of revefenacin, the reported volume of distribution is 218 L which suggests an extensive distribution to the tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of revefenacin and its active metabolite is of 71% and 42% respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Revefenacin presents a high metabolic liability producing a rapid metabolic turnover after being distributed from the lung. This metabolic process is done primarily via enzymatic hydrolysis via CYP2D6 to its major hydrolytic metabolite THRX-195518. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After reaching maximum concentration, revefenacin concentrations decline in a biphasic manner. This elimination kinetics is observed by a rapid declining plasma concentration followed by a slow apparent bi-exponential elimination. Renal elimination of revefenacin is limited and it presents a mean cumulative amount excreted in urine as the unchanged drug of < 0.2% of the administered dose. Following intravenous revefenacin administration, 54% of the dose is recovered in feces and 27% was recovered in urine which confirms a high hepatobiliary processing. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent terminal half-life of a dose of 350 mcg of revefenacin was 22.3-70 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The renal clearance of revefenacin is negligible and thus, the clearance rate is not a major parameter for this drug. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Revefenacin does not produce the typical systemic effects associated with anticholinergic therapies. In carcinogenic studies in animals, there was no evidence of tumorigenicity. As well, there was no evidence of mutagenicity in the Ames test nor genotoxicity in in vitro mouse lymphoma assays and in vivo rat bone marrow micronucleus assays. There is no effect in the fertility. In overdose situations, the common signs and symptoms are nausea, vomiting, dizziness, lightheadedness, blurred vision, increased intraocular pressure, obstipation and difficulties in voiding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Revefenacin is an anticholinergic agent used to treat COPD. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Ribociclib interact?

•Drug A: Abatacept •Drug B: Ribociclib •Severity: MAJOR •Description: The metabolism of Ribociclib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Kisqali (ribociclib) is a selective cyclin-dependent kinase inhibitor, a class of drugs that help slow the progression of cancer by inhibiting two proteins called cyclin-dependent kinase 4 and 6 (CDK4/6). These proteins, when over-activated, can enable cancer cells to grow and divide too quickly. Targeting CDK4/6 with enhanced precision may play a role in ensuring that cancer cells do not continue to replicate uncontrollably. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inhibition of cyclin-dependent kinase 4 and 6 (CDK4/6) may provide protection against oncogenic processes in specific tissue types. For example, CDK4 is not required for normal mammary tissue development based on knockout mouse studies, but it is needed for growth of Ras-induced mammary tumors, suggesting a potential therapeutic window for treatment with lower toxicity. Ribociclib was reported to be a most selective CDK4/6 inhibitor and to have dose dependent antitumor activity in a number of preclinical models. It inhibited growth of tumor cells by arresting the cells at the G1 checkpoint, which prevents the tumor cells from proliferating. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ribociclib is orally bioavailable, highly selective inhibitor of CDK4/6 kinases with inhibitory IC50 concentrations in the low nanomolar range. Following oral dosing, ribociclib was rapidly absorbed with median Tmax ranging from 1 to 5 hours. Plasma concentrations increased approximately 2- to 3-fold from Cycle 1 Day 1 to Cycle 1 Day 18/21 due to accumulation, with steady state reached by approximately Day 8 on the basis of trough concentrations after repeated daily dosing. Dose-proportionality analyses demonstrated that exposure to ribociclib increased with dose, with both Cmax and area under the curve (AUC) increasing slightly more than proportional to dose, over the dose range 50–1,200 mg/day •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 32.6 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kisqali 200 Mg Daily Dose Carton, Kisqali Femara Co-pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ribociclib is a kinase inhibitor used to treat HR+, HER2- advanced or metastatic breast cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Ribociclib interact? Information: •Drug A: Abatacept •Drug B: Ribociclib •Severity: MAJOR •Description: The metabolism of Ribociclib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Kisqali (ribociclib) is a selective cyclin-dependent kinase inhibitor, a class of drugs that help slow the progression of cancer by inhibiting two proteins called cyclin-dependent kinase 4 and 6 (CDK4/6). These proteins, when over-activated, can enable cancer cells to grow and divide too quickly. Targeting CDK4/6 with enhanced precision may play a role in ensuring that cancer cells do not continue to replicate uncontrollably. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inhibition of cyclin-dependent kinase 4 and 6 (CDK4/6) may provide protection against oncogenic processes in specific tissue types. For example, CDK4 is not required for normal mammary tissue development based on knockout mouse studies, but it is needed for growth of Ras-induced mammary tumors, suggesting a potential therapeutic window for treatment with lower toxicity. Ribociclib was reported to be a most selective CDK4/6 inhibitor and to have dose dependent antitumor activity in a number of preclinical models. It inhibited growth of tumor cells by arresting the cells at the G1 checkpoint, which prevents the tumor cells from proliferating. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ribociclib is orally bioavailable, highly selective inhibitor of CDK4/6 kinases with inhibitory IC50 concentrations in the low nanomolar range. Following oral dosing, ribociclib was rapidly absorbed with median Tmax ranging from 1 to 5 hours. Plasma concentrations increased approximately 2- to 3-fold from Cycle 1 Day 1 to Cycle 1 Day 18/21 due to accumulation, with steady state reached by approximately Day 8 on the basis of trough concentrations after repeated daily dosing. Dose-proportionality analyses demonstrated that exposure to ribociclib increased with dose, with both Cmax and area under the curve (AUC) increasing slightly more than proportional to dose, over the dose range 50–1,200 mg/day •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 32.6 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kisqali 200 Mg Daily Dose Carton, Kisqali Femara Co-pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ribociclib is a kinase inhibitor used to treat HR+, HER2- advanced or metastatic breast cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Rilonacept interact?

•Drug A: Abatacept •Drug B: Rilonacept •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Rilonacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rilonacept is indicated for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS), and Muckle-Wells Syndrome (MWS) in patients aged 12 and older. Rilonacept is also indicated for the maintenance of remission of Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adult and pediatric patients weighing at least 10 kg. Finally, rilonacept is indicated for the treatment of recurrent pericarditis (RP) and to reduce the risk of RP recurrence in patients aged 12 and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Treatment with Rilonacept resulted in decreased levels of mean C-Reactive Protein (CRP) and Serum Amyloid A (SAA). Higher levels of CRP and SAA are associated with inflammatory disease activity found in patients with Cryopyrin-Associated Periodic Syndromes. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): CAPS refer to rare genetic syndromes generally caused by mutations in the NLRP-3 [Nucleotide-binding domain, leucine rich family (NLR), pyrin domain containing 3] gene (also known as Cold-Induced Auto-inflammatory Syndtrome-1 [CIAS1]). CAPS disorders are inherited in an autosomal dominant pattern with male and female offspring equally affected. Fever, urticaria-like rash, arthralgia, myalgia, fatigue, and conjunctivitis are features common to all disorders. In most cases, inflammation in CAPS is associated with mutations in the NLRP-3 gene which encodes the protein cryopyrin, an important component of the inflammasome. Cryopyrin regulates the protease caspase-1 and controls the activation of interleukin-1 beta (IL-1β). Mutations in NLRP-3 result in an overactive inflammasome resulting in excessive release of activated IL-1β that drives inflammation. Rilonacept blocks IL-1β signaling by acting as a soluble decoy receptor that binds IL-1β and prevents its interaction with cell surface receptors. Rilonacept also binds IL-1α and IL-1 receptor antagonist (IL-1ra) with reduced affinity. By binding IL-1, rilonacept prevents the activation of IL-1 receptors, thus reducing inflammatory responses and other effects related to an excess of IL-1. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 8.6 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arcalyst •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rilonacept is an IL-1 inhibitor used to treat cryopyrin-associated periodic syndrome, a rare hereditary inflammatory disorder.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Rilonacept interact? Information: •Drug A: Abatacept •Drug B: Rilonacept •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Rilonacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rilonacept is indicated for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS), and Muckle-Wells Syndrome (MWS) in patients aged 12 and older. Rilonacept is also indicated for the maintenance of remission of Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adult and pediatric patients weighing at least 10 kg. Finally, rilonacept is indicated for the treatment of recurrent pericarditis (RP) and to reduce the risk of RP recurrence in patients aged 12 and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Treatment with Rilonacept resulted in decreased levels of mean C-Reactive Protein (CRP) and Serum Amyloid A (SAA). Higher levels of CRP and SAA are associated with inflammatory disease activity found in patients with Cryopyrin-Associated Periodic Syndromes. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): CAPS refer to rare genetic syndromes generally caused by mutations in the NLRP-3 [Nucleotide-binding domain, leucine rich family (NLR), pyrin domain containing 3] gene (also known as Cold-Induced Auto-inflammatory Syndtrome-1 [CIAS1]). CAPS disorders are inherited in an autosomal dominant pattern with male and female offspring equally affected. Fever, urticaria-like rash, arthralgia, myalgia, fatigue, and conjunctivitis are features common to all disorders. In most cases, inflammation in CAPS is associated with mutations in the NLRP-3 gene which encodes the protein cryopyrin, an important component of the inflammasome. Cryopyrin regulates the protease caspase-1 and controls the activation of interleukin-1 beta (IL-1β). Mutations in NLRP-3 result in an overactive inflammasome resulting in excessive release of activated IL-1β that drives inflammation. Rilonacept blocks IL-1β signaling by acting as a soluble decoy receptor that binds IL-1β and prevents its interaction with cell surface receptors. Rilonacept also binds IL-1α and IL-1 receptor antagonist (IL-1ra) with reduced affinity. By binding IL-1, rilonacept prevents the activation of IL-1 receptors, thus reducing inflammatory responses and other effects related to an excess of IL-1. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 8.6 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arcalyst •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rilonacept is an IL-1 inhibitor used to treat cryopyrin-associated periodic syndrome, a rare hereditary inflammatory disorder. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Rilpivirine interact?

•Drug A: Abatacept •Drug B: Rilpivirine •Severity: MODERATE •Description: The metabolism of Rilpivirine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rilpivirine, in combination with other agents, is indicated for the treatment of HIV-1 infections in antiretroviral treatment-naive patients with HIV-1 RNA ≤100,000 copies/mL and CD4+ cell count >200 cells/mm. The FDA combination therapy approval of rilpivirine and dolutegravir is indicated for adults and adolescents 12 years of age and older weighing at least 35 kg with HIV-1 infections whose virus is currently suppressed (< 50 copies/ml) on a stable regimen for at least six months, without a history of treatment failure and no known substitutions associated to resistance to any of the two components of the therapy. Rilpivirine in combination with cabotegravir is indicated as a complete regimen for the treatment of HIV-1 infection in adults and adolescents - ≥12 years old and weighing at least 35kg - to replace the current antiretroviral regimen in those who are virologically suppressed (HIV-1 RNA <50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and with no known or suspected resistance to either cabotegravir or rilpivirine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rilpivirine is a non-nucleoside reverse transcriptase inhibitor that inhibits the replication of HIV-1. It has a long duration of action as the oral tablet is given daily and the intramuscular suspension is given monthly. Patients should be counselled regarding the risk of hypersensitivity reactions, hepatotoxicity, depressive disorders, and the redistribution or accumulation of body fat. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rilpivirine is a non-competitive NNRTI that binds to reverse transcriptase. Its binding results in the blockage of RNA and DNA- dependent DNA polymerase activities, like HIV-1 replication. It does not present activity against human DNA polymerases α, β and γ. Rilpivirine's flexible structure around the aromatic rings allows the adaptation to changes in the non-nucleoside RT binding pocket, reducing the likelihood of viral mutations conferring resistance. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rilpivirine has a T max of 3-4 hours and has a mean AUC of 2235 ± 851 ng*h/mL. A 25mg dose reaches a C max of 247 ng/mL in healthy subjects and 138.6 ng/mL in patients with HIV-1. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In HIV-1 patients, the apparent volume of distribution in the central compartment was 152-173 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rilpivirine is >99% bound to plasma protein, most commonly albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rilpivirine is predominantly metabolized by CYP3A4 and CYP3A5 to the hydroxylated metabolites M1, M2, M3, and M4. UGT1A1 glucuronidates the M2 metabolite to form M6, UGT1A4 glucuronidates rilpivirine to form M5, and an unknown UGT glucuronidates the M4 metabolite to form M7. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rilpivirine is 85% eliminated in the feces and 6.1% eliminated in the urine. 25% of a dose is recovered in the feces as the unchanged parent drug, while <1% of a dose is recovered in the urine as the unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Rilpivirine has a terminal half-life of 34-55 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In HIV-1 patients, the apparent total clearance is estimated to be 6.89-8.66 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of an overdose, contact a poison control centre. Patients should be treated with symptomatic and supportive measures, including monitoring of the QT interval. Dialysis is not expected to remove significant amounts of the drug from plasma as it is highly bound to albumin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Complera, Edurant, Juluca, Odefsey •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rilpivirina Rilpivirine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used in combination with other antiretrovirals to specifically treat human immunodeficiency virus type 1 (HIV-1).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rilpivirine interact? Information: •Drug A: Abatacept •Drug B: Rilpivirine •Severity: MODERATE •Description: The metabolism of Rilpivirine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rilpivirine, in combination with other agents, is indicated for the treatment of HIV-1 infections in antiretroviral treatment-naive patients with HIV-1 RNA ≤100,000 copies/mL and CD4+ cell count >200 cells/mm. The FDA combination therapy approval of rilpivirine and dolutegravir is indicated for adults and adolescents 12 years of age and older weighing at least 35 kg with HIV-1 infections whose virus is currently suppressed (< 50 copies/ml) on a stable regimen for at least six months, without a history of treatment failure and no known substitutions associated to resistance to any of the two components of the therapy. Rilpivirine in combination with cabotegravir is indicated as a complete regimen for the treatment of HIV-1 infection in adults and adolescents - ≥12 years old and weighing at least 35kg - to replace the current antiretroviral regimen in those who are virologically suppressed (HIV-1 RNA <50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and with no known or suspected resistance to either cabotegravir or rilpivirine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rilpivirine is a non-nucleoside reverse transcriptase inhibitor that inhibits the replication of HIV-1. It has a long duration of action as the oral tablet is given daily and the intramuscular suspension is given monthly. Patients should be counselled regarding the risk of hypersensitivity reactions, hepatotoxicity, depressive disorders, and the redistribution or accumulation of body fat. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rilpivirine is a non-competitive NNRTI that binds to reverse transcriptase. Its binding results in the blockage of RNA and DNA- dependent DNA polymerase activities, like HIV-1 replication. It does not present activity against human DNA polymerases α, β and γ. Rilpivirine's flexible structure around the aromatic rings allows the adaptation to changes in the non-nucleoside RT binding pocket, reducing the likelihood of viral mutations conferring resistance. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rilpivirine has a T max of 3-4 hours and has a mean AUC of 2235 ± 851 ng*h/mL. A 25mg dose reaches a C max of 247 ng/mL in healthy subjects and 138.6 ng/mL in patients with HIV-1. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In HIV-1 patients, the apparent volume of distribution in the central compartment was 152-173 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rilpivirine is >99% bound to plasma protein, most commonly albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rilpivirine is predominantly metabolized by CYP3A4 and CYP3A5 to the hydroxylated metabolites M1, M2, M3, and M4. UGT1A1 glucuronidates the M2 metabolite to form M6, UGT1A4 glucuronidates rilpivirine to form M5, and an unknown UGT glucuronidates the M4 metabolite to form M7. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rilpivirine is 85% eliminated in the feces and 6.1% eliminated in the urine. 25% of a dose is recovered in the feces as the unchanged parent drug, while <1% of a dose is recovered in the urine as the unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Rilpivirine has a terminal half-life of 34-55 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In HIV-1 patients, the apparent total clearance is estimated to be 6.89-8.66 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of an overdose, contact a poison control centre. Patients should be treated with symptomatic and supportive measures, including monitoring of the QT interval. Dialysis is not expected to remove significant amounts of the drug from plasma as it is highly bound to albumin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Complera, Edurant, Juluca, Odefsey •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rilpivirina Rilpivirine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rilpivirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) used in combination with other antiretrovirals to specifically treat human immunodeficiency virus type 1 (HIV-1). Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Riluzole interact?

•Drug A: Abatacept •Drug B: Riluzole •Severity: MODERATE •Description: The metabolism of Riluzole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of amyotrophic lateral sclerosis (ALS, Lou Gehrig's Disease) •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Riluzole, a member of the benzothiazole class, is indicated for the treatment of patients with amyotrophic lateral sclerosis (ALS). Riluzole extends survival and/or time to tracheostomy. It is also neuroprotective in various in vivo experimental models of neuronal injury involving excitotoxic mechanisms. The etiology and pathogenesis of amyotrophic lateral sclerosis (ALS) are not known, although a number of hypotheses have been advanced. One hypothesis is that motor neurons, made vulnerable through either genetic predisposition or environmental factors, are injured by glutamate. In some cases of familial ALS the enzyme superoxide dismutase has been found to be defective. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Riluzole is well-absorbed (approximately 90%), with average absolute oral bioavailability of about 60% (CV=30%). A high fat meal decreases absorption, reducing AUC by about 20% and peak blood levels by about 45%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96% bound to plasma proteins, mainly to albumin and lipoprotein over the clinical concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Riluzole is extensively metabolized to six major and a number of minor metabolites, which have not all been identified to date. Metabolism is mostly hepatic, consisting of cytochrome P450–dependent hydroxylation and glucuronidation. CYP1A2 is the primary isozyme involved in N-hydroxylation; CYP2D6, CYP2C19, CYP3A4, and CYP2E1 are considered unlikely to contribute significantly to riluzole metabolism in humans. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of riluzole is 12 hours (CV=35%) after repeated doses. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Exservan, Rilutek, Tiglutik •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Riluzole is a glutamate antagonist used to treat amyotrophic lateral sclerosis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Riluzole interact? Information: •Drug A: Abatacept •Drug B: Riluzole •Severity: MODERATE •Description: The metabolism of Riluzole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of amyotrophic lateral sclerosis (ALS, Lou Gehrig's Disease) •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Riluzole, a member of the benzothiazole class, is indicated for the treatment of patients with amyotrophic lateral sclerosis (ALS). Riluzole extends survival and/or time to tracheostomy. It is also neuroprotective in various in vivo experimental models of neuronal injury involving excitotoxic mechanisms. The etiology and pathogenesis of amyotrophic lateral sclerosis (ALS) are not known, although a number of hypotheses have been advanced. One hypothesis is that motor neurons, made vulnerable through either genetic predisposition or environmental factors, are injured by glutamate. In some cases of familial ALS the enzyme superoxide dismutase has been found to be defective. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mode of action of riluzole is unknown. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Riluzole is well-absorbed (approximately 90%), with average absolute oral bioavailability of about 60% (CV=30%). A high fat meal decreases absorption, reducing AUC by about 20% and peak blood levels by about 45%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96% bound to plasma proteins, mainly to albumin and lipoprotein over the clinical concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Riluzole is extensively metabolized to six major and a number of minor metabolites, which have not all been identified to date. Metabolism is mostly hepatic, consisting of cytochrome P450–dependent hydroxylation and glucuronidation. CYP1A2 is the primary isozyme involved in N-hydroxylation; CYP2D6, CYP2C19, CYP3A4, and CYP2E1 are considered unlikely to contribute significantly to riluzole metabolism in humans. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of riluzole is 12 hours (CV=35%) after repeated doses. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Exservan, Rilutek, Tiglutik •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Riluzole is a glutamate antagonist used to treat amyotrophic lateral sclerosis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Riociguat interact?

•Drug A: Abatacept •Drug B: Riociguat •Severity: MODERATE •Description: The metabolism of Riociguat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Riociguat is indicated for the treatment of adults with persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH), (WHO Group 4) after surgical treatment, or inoperable CTEPH, to improve exercise capacity and WHO functional class. Riociguat is indicated for the treatment of adults with pulmonary arterial hypertension (PAH), (WHO Group 1), to improve exercise capacity, WHO functional class and to delay clinical worsening. Efficacy was shown in patients on Riociguat monotherapy or in combination with endothelin receptor antagonists or prostanoids. Studies establishing effectiveness included predominately patients with WHO functional class II–III and etiologies of idiopathic or heritable PAH (61%) or PAH associated with connective tissue diseases (25%). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Riociguat is a stimulator of soluble guanylate cyclase (sGC), an enzyme in the cardiopulmonary system and the receptor for nitric oxide (NO). When NO binds to sGC, the enzyme catalyzes synthesis of the signaling molecule cyclic guanosine monophosphate (cGMP). Intracellular cGMP plays an important role in regulating processes that influence vascular tone, proliferation, fibrosis and inflammation. Pulmonary hypertension is associated with endothelial dysfunction, impaired synthesis of nitric oxide and insufficient stimulation of the NO-sGC-cGMP pathway. Riociguat has a dual mode of action. It sensitizes sGC to endogenous NO by stabilizing the NO-sGC binding. Riociguat also directly stimulates sGC via a different binding site, independently of NO. Riociguat stimulates the NO-sGC-cGMP pathway and leads to increased generation of cGMP with subsequent vasodilation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The pharmacokinetics of riociguant are dose proportional from 0.5 mg to 2.5 mg. The absolute bioavailability is approximately 94%. After oral administration, peak plasma concentrations were achieved within 1.5 hours. Food does not affect the bioavailability of riociguat. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state = 30 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95% with serum albumin and alpha-1–acidic glycoprotein being the main binding components. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The active metabolite (M1) of riociguat is 1/3 to 1/10 as potent as riociguat. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Riociguat is eliminated in the urine (40%) and feces (53%), largely as metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): About 12 hours in patients and 7 hours in healthy subjects. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): EMBRYO-FETAL TOXICITY Do not administer Riociguat to a pregnant female because it may cause fetal harm. Females of reproductive potential: Exclude pregnancy before the start of treatment, monthly during treatment, and 1 month after stopping treatment. Prevent pregnancy during treatment and for one month after stopping treatment by using acceptable methods of contraception. For all female patients, Riociguat is available only through a restricted program called the Adempas Risk Evaluation and Mitigation Strategy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adempas •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Riociguat Riociguatum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Riociguat is a stimulator of soluble guanylate cyclase indicated for the management of persistent or recurrent chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Riociguat interact? Information: •Drug A: Abatacept •Drug B: Riociguat •Severity: MODERATE •Description: The metabolism of Riociguat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Riociguat is indicated for the treatment of adults with persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH), (WHO Group 4) after surgical treatment, or inoperable CTEPH, to improve exercise capacity and WHO functional class. Riociguat is indicated for the treatment of adults with pulmonary arterial hypertension (PAH), (WHO Group 1), to improve exercise capacity, WHO functional class and to delay clinical worsening. Efficacy was shown in patients on Riociguat monotherapy or in combination with endothelin receptor antagonists or prostanoids. Studies establishing effectiveness included predominately patients with WHO functional class II–III and etiologies of idiopathic or heritable PAH (61%) or PAH associated with connective tissue diseases (25%). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Riociguat is a stimulator of soluble guanylate cyclase (sGC), an enzyme in the cardiopulmonary system and the receptor for nitric oxide (NO). When NO binds to sGC, the enzyme catalyzes synthesis of the signaling molecule cyclic guanosine monophosphate (cGMP). Intracellular cGMP plays an important role in regulating processes that influence vascular tone, proliferation, fibrosis and inflammation. Pulmonary hypertension is associated with endothelial dysfunction, impaired synthesis of nitric oxide and insufficient stimulation of the NO-sGC-cGMP pathway. Riociguat has a dual mode of action. It sensitizes sGC to endogenous NO by stabilizing the NO-sGC binding. Riociguat also directly stimulates sGC via a different binding site, independently of NO. Riociguat stimulates the NO-sGC-cGMP pathway and leads to increased generation of cGMP with subsequent vasodilation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The pharmacokinetics of riociguant are dose proportional from 0.5 mg to 2.5 mg. The absolute bioavailability is approximately 94%. After oral administration, peak plasma concentrations were achieved within 1.5 hours. Food does not affect the bioavailability of riociguat. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state = 30 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95% with serum albumin and alpha-1–acidic glycoprotein being the main binding components. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The active metabolite (M1) of riociguat is 1/3 to 1/10 as potent as riociguat. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Riociguat is eliminated in the urine (40%) and feces (53%), largely as metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): About 12 hours in patients and 7 hours in healthy subjects. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): EMBRYO-FETAL TOXICITY Do not administer Riociguat to a pregnant female because it may cause fetal harm. Females of reproductive potential: Exclude pregnancy before the start of treatment, monthly during treatment, and 1 month after stopping treatment. Prevent pregnancy during treatment and for one month after stopping treatment by using acceptable methods of contraception. For all female patients, Riociguat is available only through a restricted program called the Adempas Risk Evaluation and Mitigation Strategy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adempas •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Riociguat Riociguatum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Riociguat is a stimulator of soluble guanylate cyclase indicated for the management of persistent or recurrent chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Risankizumab interact?

•Drug A: Abatacept •Drug B: Risankizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Risankizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Risankizumab is indicated to treat: moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. active psoriatic arthritis in adults. In Canada and Europe, it may be used alone or in combination with a conventional non-biologic disease-modifying antirheumatic drug (cDMARD) (e.g., methotrexate). moderately to severely active Crohn's disease in adults. In Canada, it is used in patients who have had an inadequate response, intolerance, or demonstrated dependence on corticosteroids; or an inadequate response, intolerance, or loss of response to immunomodulators or biologic therapies. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Risankizumab works to suppress the inflammatory effects of interleukin (IL)-23. It inhibits the release of pro-inflammatory cytokines and chemokines. In vitro, risankizumab blocked IL-17 production; however, risankizumab does not actually bind to IL-17. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin (IL)-23 is a pro-inflammatory cytokine implicated in various chronic inflammatory disorders, such as plaque psoriasis, psoriatic arthritis, and Crohn's disease. IL-23 binds to the IL-23 receptor to activate the IL-23/Th17 axis, which is responsible for mediating T cell-mediated immune responses and inflammation. The IL-23/Th17 axis triggers the differentiation of Th-17 and Th-22 cells and induces the release of inflammatory cytokines and chemokines such as IL-17. While the IL-23/Th17 axis serves a critical role in protection against pathogens, it is also involved in chronic, autoimmune, inflammatory disorders. IL-23 is made up of two subunits, p19 and p40: p19 is specific to IL-23 and p40 is present on both IL-12 and IL-23. Risankizumab binds to the p19 subunit of IL-23 with high affinity and neutralizes it, thereby preventing its interaction with the IL-23 receptor and activation of IL-23 signalling cascades. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Drug plasma concentrations increased dose-proportionally after subcutaneous administration of a single dose over the dose range from 18 mg to 360 mg and intravenous administration over a dose range from 200 mg to 1800 mg via a 3-hour infusion. In patients with plaque psoriasis who received a subcutaneous dose of 150 mg risankizumab, steady-state peak concentration (C max ) and trough concentration (C trough ) were 12 mcg/mL and 2 mcg/mL, respectively. In subjects with Crohn’s disease treated with 600 mg intravenous induction dose at Weeks 0, 4, and 8, followed by 180 mg or 360 mg subcutaneous maintenance dose at Week 12 and every 8 weeks thereafter, the median Cmax and Ctrough are estimated to be 156 mcg/mL and 38.8 mcg/mL, respectively, during Weeks 8-12; and the steady state median Cmax and Ctrough are estimated to be 14.0 mcg/mL and 4.1 mcg/mL, respectively for 180 mg or 28.0 mcg/mL and 8.1 mcg/mL, respectively, for 360 mg, during Weeks 40-48. The absolute bioavailability of risankizumab was approximately 74 to 89% following subcutaneous injection. In healthy subjects, following administration of a single subcutaneous dose, C max was reached by 3 to 14 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated steady-state volume of distribution (inter-subject CV%) was 11.2 L (34%) in subjects with plaque psoriasis, and 7.68 L (64%) in subjects with Crohn’s disease. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No information is available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolic pathway of risankizumab has not been fully characterized. As a humanized IgG1 monoclonal antibody, it is likely to be catabolized into small peptides and amino acids in the same way as endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As an IgG1 monoclonal antibody, risankizumab is not expected to be filtered by glomerular filtration in the kidneys or to be excreted as an intact molecule in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life was approximately 28 days in patients with plaque psoriasis and 21 days in patients with Crohn’s disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The estimated systemic clearance (inter-subject CV%) was 0.31 L/day (24%) in patients with plaque psoriasis and 0.30 L/day (34%) in patients with Crohn’s disease. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The NOAEL was 50 mg/kg in monkeys following intravenous or subcutaneous administration. There is no information available regarding the overdose of risankizumab. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Skyrizi 150 Mg Dose Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Risankizumab is an interleukin-23 antagonist used to treat plaque psoriasis, psoriatic arthritis, and Crohn's disease in adults.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Risankizumab interact? Information: •Drug A: Abatacept •Drug B: Risankizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Risankizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Risankizumab is indicated to treat: moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. active psoriatic arthritis in adults. In Canada and Europe, it may be used alone or in combination with a conventional non-biologic disease-modifying antirheumatic drug (cDMARD) (e.g., methotrexate). moderately to severely active Crohn's disease in adults. In Canada, it is used in patients who have had an inadequate response, intolerance, or demonstrated dependence on corticosteroids; or an inadequate response, intolerance, or loss of response to immunomodulators or biologic therapies. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Risankizumab works to suppress the inflammatory effects of interleukin (IL)-23. It inhibits the release of pro-inflammatory cytokines and chemokines. In vitro, risankizumab blocked IL-17 production; however, risankizumab does not actually bind to IL-17. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin (IL)-23 is a pro-inflammatory cytokine implicated in various chronic inflammatory disorders, such as plaque psoriasis, psoriatic arthritis, and Crohn's disease. IL-23 binds to the IL-23 receptor to activate the IL-23/Th17 axis, which is responsible for mediating T cell-mediated immune responses and inflammation. The IL-23/Th17 axis triggers the differentiation of Th-17 and Th-22 cells and induces the release of inflammatory cytokines and chemokines such as IL-17. While the IL-23/Th17 axis serves a critical role in protection against pathogens, it is also involved in chronic, autoimmune, inflammatory disorders. IL-23 is made up of two subunits, p19 and p40: p19 is specific to IL-23 and p40 is present on both IL-12 and IL-23. Risankizumab binds to the p19 subunit of IL-23 with high affinity and neutralizes it, thereby preventing its interaction with the IL-23 receptor and activation of IL-23 signalling cascades. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Drug plasma concentrations increased dose-proportionally after subcutaneous administration of a single dose over the dose range from 18 mg to 360 mg and intravenous administration over a dose range from 200 mg to 1800 mg via a 3-hour infusion. In patients with plaque psoriasis who received a subcutaneous dose of 150 mg risankizumab, steady-state peak concentration (C max ) and trough concentration (C trough ) were 12 mcg/mL and 2 mcg/mL, respectively. In subjects with Crohn’s disease treated with 600 mg intravenous induction dose at Weeks 0, 4, and 8, followed by 180 mg or 360 mg subcutaneous maintenance dose at Week 12 and every 8 weeks thereafter, the median Cmax and Ctrough are estimated to be 156 mcg/mL and 38.8 mcg/mL, respectively, during Weeks 8-12; and the steady state median Cmax and Ctrough are estimated to be 14.0 mcg/mL and 4.1 mcg/mL, respectively for 180 mg or 28.0 mcg/mL and 8.1 mcg/mL, respectively, for 360 mg, during Weeks 40-48. The absolute bioavailability of risankizumab was approximately 74 to 89% following subcutaneous injection. In healthy subjects, following administration of a single subcutaneous dose, C max was reached by 3 to 14 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated steady-state volume of distribution (inter-subject CV%) was 11.2 L (34%) in subjects with plaque psoriasis, and 7.68 L (64%) in subjects with Crohn’s disease. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No information is available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolic pathway of risankizumab has not been fully characterized. As a humanized IgG1 monoclonal antibody, it is likely to be catabolized into small peptides and amino acids in the same way as endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As an IgG1 monoclonal antibody, risankizumab is not expected to be filtered by glomerular filtration in the kidneys or to be excreted as an intact molecule in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life was approximately 28 days in patients with plaque psoriasis and 21 days in patients with Crohn’s disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The estimated systemic clearance (inter-subject CV%) was 0.31 L/day (24%) in patients with plaque psoriasis and 0.30 L/day (34%) in patients with Crohn’s disease. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The NOAEL was 50 mg/kg in monkeys following intravenous or subcutaneous administration. There is no information available regarding the overdose of risankizumab. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Skyrizi 150 Mg Dose Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Risankizumab is an interleukin-23 antagonist used to treat plaque psoriasis, psoriatic arthritis, and Crohn's disease in adults. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Risperidone interact?

•Drug A: Abatacept •Drug B: Risperidone •Severity: MODERATE •Description: The metabolism of Risperidone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Risperidone is indicated for the treatment of schizophrenia and irritability associated with autistic disorder. It is also indicated as monotherapy, or adjunctly with lithium or valproic acid, for the treatment of acute mania or mixed episodes associated with bipolar I disorder. Risperidone is additionally indicated in Canada for the short-term symptomatic management of aggression or psychotic symptoms in patients with severe dementia of the Alzheimer type unresponsive to nonpharmacological approaches. Risperidone is also used off-label for a number of conditions including as an adjunct to antidepressants in treatment-resistant depression. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The primary action of risperidone is to decrease dopaminergic and serotonergic pathway activity in the brain, therefore decreasing symptoms of schizophrenia and mood disorders. Risperidone has a high binding affinity for serotonergic 5-HT2A receptors when compared to dopaminergic D2 receptors in the brain. Risperidone binds to D2 receptors with a lower affinity than first-generation antipsychotic drugs, which bind with very high affinity. A reduction in extrapyramidal symptoms with risperidone, when compared to its predecessors, is likely a result of its moderate affinity for dopaminergic D2 receptors. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Though its precise mechanism of action is not fully understood, current focus is on the ability of risperidone to inhibit the D2 dopaminergic receptors and 5-HT2A serotonergic receptors in the brain. Schizophrenia is thought to result from an excess of dopaminergic D2 and serotonergic 5-HT2A activity, resulting in overactivity of central mesolimbic pathways and mesocortical pathways, respectively. D2 dopaminergic receptors are transiently inhibited by risperidone, reducing dopaminergic neurotransmission, therefore decreasing positive symptoms of schizophrenia, such as delusions and hallucinations. Risperidone binds transiently and with loose affinity to the dopaminergic D2 receptor, with an ideal receptor occupancy of 60-70% for optimal effect. Rapid dissociation of risperidone from the D2 receptors contributes to decreased risk of extrapyramidal symptoms (EPS), which occur with permanent and high occupancy blockade of D2 dopaminergic receptors. Low-affinity binding and rapid dissociation from the D2 receptor distinguish risperidone from the traditional antipsychotic drugs. A higher occupancy rate of D2 receptors is said to increase the risk of extrapyramidal symptoms and is therefore to be avoided. Increased serotonergic mesocortical activity in schizophrenia results in negative symptoms, such as depression and decreased motivation. The high-affinity binding of risperidone to 5-HT2A receptors leads to a decrease in serotonergic activity. In addition, 5-HT2A receptor blockade results in decreased risk of extrapyramidal symptoms, likely by increasing dopamine release from the frontal cortex, and not the nigrostriatal tract. Dopamine level is therefore not completely inhibited. Through the above mechanisms, both serotonergic and D2 blockade by risperidone are thought to synergistically work to decrease the risk of extrapyramidal symptoms. Risperidone has also been said to be an antagonist of alpha-1 (α1), alpha-2 (α2), and histamine (H1) receptors. Blockade of these receptors is thought to improve symptoms of schizophrenia, however the exact mechanism of action on these receptors is not fully understood at this time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed. The absolute oral bioavailability of risperidone is 70% (CV=25%). The relative oral bioavailability of risperidone from a tablet is 94% (CV=10%) when compared to a solution. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of risperidone is approximately 1 to 2 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Risperidone and its active metabolite, 9-hydroxyrisperidone, are ~88% and ~77% protein-bound in human plasma, respectively. They each bind to both serum albumin and alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized by hepatic cytochrome P450 2D6 isozyme to 9-hydroxyrisperidone (i.e. paliperidone ), which has approximately the same receptor binding affinity as risperidone. Hydroxylation is dependent on debrisoquine 4-hydroxylase and metabolism is sensitive to genetic polymorphisms in debrisoquine 4-hydroxylase. Risperidone also undergoes N-dealkylation to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Risperidone is extensively metabolized in the liver. In healthy elderly subjects, renal clearance of both risperidone and 9-hydroxyrisperidone was decreased, and elimination half-lives are prolonged compared to young healthy subjects. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3 hours in extensive metabolizers Up to 20 hours in poor metabolizers •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Risperidone is cleared by the kidneys. Clearance is decreased in the elderly and those with a creatinine clearance (ClCr) between 15-59 mL/min, in whom clearance is decreased by approximately 60%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include lethargy, dystonia/spasm, tachycardia, bradycardia, and seizures. LD 50 =57.7 mg/kg (rat, oral) and 34 mg/kg (rat, intravenous). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Perseris, Risperdal, Rykindo, Uzedy •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Risperidone is a second-generation antipsychotic medication used to treat a number of mental health disorders including schizophrenia, bipolar mania, psychosis, or as an adjunct in severe depression.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Risperidone interact? Information: •Drug A: Abatacept •Drug B: Risperidone •Severity: MODERATE •Description: The metabolism of Risperidone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Risperidone is indicated for the treatment of schizophrenia and irritability associated with autistic disorder. It is also indicated as monotherapy, or adjunctly with lithium or valproic acid, for the treatment of acute mania or mixed episodes associated with bipolar I disorder. Risperidone is additionally indicated in Canada for the short-term symptomatic management of aggression or psychotic symptoms in patients with severe dementia of the Alzheimer type unresponsive to nonpharmacological approaches. Risperidone is also used off-label for a number of conditions including as an adjunct to antidepressants in treatment-resistant depression. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The primary action of risperidone is to decrease dopaminergic and serotonergic pathway activity in the brain, therefore decreasing symptoms of schizophrenia and mood disorders. Risperidone has a high binding affinity for serotonergic 5-HT2A receptors when compared to dopaminergic D2 receptors in the brain. Risperidone binds to D2 receptors with a lower affinity than first-generation antipsychotic drugs, which bind with very high affinity. A reduction in extrapyramidal symptoms with risperidone, when compared to its predecessors, is likely a result of its moderate affinity for dopaminergic D2 receptors. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Though its precise mechanism of action is not fully understood, current focus is on the ability of risperidone to inhibit the D2 dopaminergic receptors and 5-HT2A serotonergic receptors in the brain. Schizophrenia is thought to result from an excess of dopaminergic D2 and serotonergic 5-HT2A activity, resulting in overactivity of central mesolimbic pathways and mesocortical pathways, respectively. D2 dopaminergic receptors are transiently inhibited by risperidone, reducing dopaminergic neurotransmission, therefore decreasing positive symptoms of schizophrenia, such as delusions and hallucinations. Risperidone binds transiently and with loose affinity to the dopaminergic D2 receptor, with an ideal receptor occupancy of 60-70% for optimal effect. Rapid dissociation of risperidone from the D2 receptors contributes to decreased risk of extrapyramidal symptoms (EPS), which occur with permanent and high occupancy blockade of D2 dopaminergic receptors. Low-affinity binding and rapid dissociation from the D2 receptor distinguish risperidone from the traditional antipsychotic drugs. A higher occupancy rate of D2 receptors is said to increase the risk of extrapyramidal symptoms and is therefore to be avoided. Increased serotonergic mesocortical activity in schizophrenia results in negative symptoms, such as depression and decreased motivation. The high-affinity binding of risperidone to 5-HT2A receptors leads to a decrease in serotonergic activity. In addition, 5-HT2A receptor blockade results in decreased risk of extrapyramidal symptoms, likely by increasing dopamine release from the frontal cortex, and not the nigrostriatal tract. Dopamine level is therefore not completely inhibited. Through the above mechanisms, both serotonergic and D2 blockade by risperidone are thought to synergistically work to decrease the risk of extrapyramidal symptoms. Risperidone has also been said to be an antagonist of alpha-1 (α1), alpha-2 (α2), and histamine (H1) receptors. Blockade of these receptors is thought to improve symptoms of schizophrenia, however the exact mechanism of action on these receptors is not fully understood at this time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed. The absolute oral bioavailability of risperidone is 70% (CV=25%). The relative oral bioavailability of risperidone from a tablet is 94% (CV=10%) when compared to a solution. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of risperidone is approximately 1 to 2 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Risperidone and its active metabolite, 9-hydroxyrisperidone, are ~88% and ~77% protein-bound in human plasma, respectively. They each bind to both serum albumin and alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized by hepatic cytochrome P450 2D6 isozyme to 9-hydroxyrisperidone (i.e. paliperidone ), which has approximately the same receptor binding affinity as risperidone. Hydroxylation is dependent on debrisoquine 4-hydroxylase and metabolism is sensitive to genetic polymorphisms in debrisoquine 4-hydroxylase. Risperidone also undergoes N-dealkylation to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Risperidone is extensively metabolized in the liver. In healthy elderly subjects, renal clearance of both risperidone and 9-hydroxyrisperidone was decreased, and elimination half-lives are prolonged compared to young healthy subjects. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3 hours in extensive metabolizers Up to 20 hours in poor metabolizers •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Risperidone is cleared by the kidneys. Clearance is decreased in the elderly and those with a creatinine clearance (ClCr) between 15-59 mL/min, in whom clearance is decreased by approximately 60%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include lethargy, dystonia/spasm, tachycardia, bradycardia, and seizures. LD 50 =57.7 mg/kg (rat, oral) and 34 mg/kg (rat, intravenous). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Perseris, Risperdal, Rykindo, Uzedy •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Risperidone is a second-generation antipsychotic medication used to treat a number of mental health disorders including schizophrenia, bipolar mania, psychosis, or as an adjunct in severe depression. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Ritlecitinib interact?

•Drug A: Abatacept •Drug B: Ritlecitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ritlecitinib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ritlecitinib is indicated for the treatment of severe alopecia areata in adults and adolescents 12 years and older. It is not recommended for use in combination with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ritlecitinib is a kinase inhibitor that promotes the decrease of absolute lymphocyte levels, T lymphocytes (CD3) and T lymphocyte subsets (CD4 and CD8) in a dose-dependent manner. Ritlecitinib also promotes a decrease in NK cells (CD16/56), which remain stable up to week 48 after initiating treatment. In patients treated with 50 mg of ritlecitinib once a day, the decrease in median lymphocyte levels remains consistent up to week 48. At 12 times the mean maximum exposure of the 50 mg dose given to patients with alopecia areata once a day, ritlecitinib did not cause a clinically relevant effect on the QTc interval.[] The use of ritlecitinib is associated with the development of serious infections, malignancies (including non-melanoma skin cancer), major adverse cardiovascular events, thromboembolic events, and hypersensitivity. In the postmarketing safety study of another JAK inhibitor in patients with rheumatoid arthritis over 50 years of age with at least one cardiovascular risk factor, JAK inhibitors were associated with a higher rate of all-cause mortality, including sudden cardiovascular death, compared to TNF blockers. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alopecia areata is an autoimmune disorder that causes hair loss mainly in the scalp but also on the face and other areas. In normal conditions, hair follicles are immune-privileged sites characterized by the presence of well-suppressed natural killer cells. However, disruptions to this system can lead to the loss of immune privilege and cause alopecia areata. Genome-wide association studies have linked the overexpression of UL16-binding protein 3 (ULBP3), a protein that binds to natural killer cell receptors, to the pathogenesis of alopecia areata. The overexpression of ULBP3 promotes the attack of cytotoxic cluster of differentiation 8-positive (CD8+) NK group 2D-positive (NKG2D+) T cells to hair follicles, leading to hair follicle dystrophy. CD8+ NKG2D+ T cells promote the inflammation of hair follicles through interferon-γ (IFN-γ) and interleukin-15 (IL-15) signaling pathways, which consequently activate Janus kinase (JAK)/signal transducer and activator of transcription (STAT) molecular pathways. Therefore, JAK inhibitors have been proposed for the treatment of alopecia areata. Ritlecitinib inhibits Janus kinase 3 (JAK3) and the tyrosine kinase expressed in hepatocellular carcinoma (TEC) kinase family in an irreversible manner by blocking the adenosine triphosphate (ATP) binding site. In vitro, ritlecitinib inhibits cytokine-induced STAT phosphorylation mediated by JAK3-dependent receptors and the signaling of immune receptors dependent on TEC kinase family members. Although it is possible that JAK inhibitors, such as ritlecitinib, inhibit the inflammatory pathways activated in alopecia areata, the precise mechanism of action has not been fully elucidated. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Up to 200 mg, the AUC 0-tau and C max of ritlecitinib increase in an approximately dose-proportional manner, and steady state is reached approximately by day 4. Ritlecitinib has an absolute oral bioavailability of approximately 64%, and 1 hour after an oral dose is administered, peak plasma concentrations are achieved. Food does not have a clinically significant impact on the systemic exposures of ritlecitinib. The co-administration of a high-fat meal and a 100 mg ritlecitinib capsule reduced C max by 32% and increased AUC inf by 11%. Ritlecitinib was administered without regard to meals during clinical trials. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ritlecitinib is predicted to have a volume of distribution of 1.3 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ritlecitinib is 14% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ritlecitinib is metabolized by cytochrome P450 (CYP) and glutathione-S-transferase (GST) enzymes. The GST enzymes participating in the metabolism of ritlecitinib include cytosolic GST A1/3, M1/3/5, P1, S1, T2, Z1 and microsomal GST 1/2/3, and the CYP enzymes participating in this process include CYP3A, CYP2C8, CYP1A2, and CYP2C9. No single route contributes to more than 25% of the total metabolism of ritlecitinib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ritlecitinib is mainly excreted through urine and feces. Approximately 66% and 20% of radiolabeled ritlecitinib are excreted in the urine and feces, respectively. Approximately 4% of the ritlecitinib dose is excreted unchanged drug in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Ritlecitinib has a terminal half-life that ranges from 1.3 to 2.3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ritlecitinib is predicted to have a blood clearance of 5.6 mL/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): During clinical trials, the highest single dose of ritlecitinib was 800 mg. No specific toxicities were identified at this dose, and the adverse reactions detected were comparable to those seen at lower doses. Pharmacokinetic studies indicate that in healthy adult volunteers given a single oral dose of 800 mg, more than 90% of ritlecitinib is expected to be eliminated within 48 hours. There is no specific antidote for overdose with ritlecitinib. In patients experiencing a ritlecitinib overdose, provide symptomatic and supportive treatment, and monitor for signs and symptoms of adverse reactions. In rats given 100 mg/kg/day of ritlecitinib (29 times the maximum recommended human dose based on AUC comparison), females had an increased incidence of combined benign and malignant thymomas, while males had a higher incidence of thyroid follicular adenomas and combined follicular adenomas and carcinomas. Ritlecitinib was negative in the bacterial reverse mutation assay and positive in an in vitro micronucleus assay in TK6 cells; however, mechanistic studies suggest that ritlecitinib is aneugenic and does not present a clinically relevant genotoxic concern. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Litfulo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ritlecitinib is a kinase inhibitor used to treat severe alopecia areata in adults and adolescents 12 years and older.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Ritlecitinib interact? Information: •Drug A: Abatacept •Drug B: Ritlecitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ritlecitinib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ritlecitinib is indicated for the treatment of severe alopecia areata in adults and adolescents 12 years and older. It is not recommended for use in combination with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ritlecitinib is a kinase inhibitor that promotes the decrease of absolute lymphocyte levels, T lymphocytes (CD3) and T lymphocyte subsets (CD4 and CD8) in a dose-dependent manner. Ritlecitinib also promotes a decrease in NK cells (CD16/56), which remain stable up to week 48 after initiating treatment. In patients treated with 50 mg of ritlecitinib once a day, the decrease in median lymphocyte levels remains consistent up to week 48. At 12 times the mean maximum exposure of the 50 mg dose given to patients with alopecia areata once a day, ritlecitinib did not cause a clinically relevant effect on the QTc interval.[] The use of ritlecitinib is associated with the development of serious infections, malignancies (including non-melanoma skin cancer), major adverse cardiovascular events, thromboembolic events, and hypersensitivity. In the postmarketing safety study of another JAK inhibitor in patients with rheumatoid arthritis over 50 years of age with at least one cardiovascular risk factor, JAK inhibitors were associated with a higher rate of all-cause mortality, including sudden cardiovascular death, compared to TNF blockers. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alopecia areata is an autoimmune disorder that causes hair loss mainly in the scalp but also on the face and other areas. In normal conditions, hair follicles are immune-privileged sites characterized by the presence of well-suppressed natural killer cells. However, disruptions to this system can lead to the loss of immune privilege and cause alopecia areata. Genome-wide association studies have linked the overexpression of UL16-binding protein 3 (ULBP3), a protein that binds to natural killer cell receptors, to the pathogenesis of alopecia areata. The overexpression of ULBP3 promotes the attack of cytotoxic cluster of differentiation 8-positive (CD8+) NK group 2D-positive (NKG2D+) T cells to hair follicles, leading to hair follicle dystrophy. CD8+ NKG2D+ T cells promote the inflammation of hair follicles through interferon-γ (IFN-γ) and interleukin-15 (IL-15) signaling pathways, which consequently activate Janus kinase (JAK)/signal transducer and activator of transcription (STAT) molecular pathways. Therefore, JAK inhibitors have been proposed for the treatment of alopecia areata. Ritlecitinib inhibits Janus kinase 3 (JAK3) and the tyrosine kinase expressed in hepatocellular carcinoma (TEC) kinase family in an irreversible manner by blocking the adenosine triphosphate (ATP) binding site. In vitro, ritlecitinib inhibits cytokine-induced STAT phosphorylation mediated by JAK3-dependent receptors and the signaling of immune receptors dependent on TEC kinase family members. Although it is possible that JAK inhibitors, such as ritlecitinib, inhibit the inflammatory pathways activated in alopecia areata, the precise mechanism of action has not been fully elucidated. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Up to 200 mg, the AUC 0-tau and C max of ritlecitinib increase in an approximately dose-proportional manner, and steady state is reached approximately by day 4. Ritlecitinib has an absolute oral bioavailability of approximately 64%, and 1 hour after an oral dose is administered, peak plasma concentrations are achieved. Food does not have a clinically significant impact on the systemic exposures of ritlecitinib. The co-administration of a high-fat meal and a 100 mg ritlecitinib capsule reduced C max by 32% and increased AUC inf by 11%. Ritlecitinib was administered without regard to meals during clinical trials. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ritlecitinib is predicted to have a volume of distribution of 1.3 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ritlecitinib is 14% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ritlecitinib is metabolized by cytochrome P450 (CYP) and glutathione-S-transferase (GST) enzymes. The GST enzymes participating in the metabolism of ritlecitinib include cytosolic GST A1/3, M1/3/5, P1, S1, T2, Z1 and microsomal GST 1/2/3, and the CYP enzymes participating in this process include CYP3A, CYP2C8, CYP1A2, and CYP2C9. No single route contributes to more than 25% of the total metabolism of ritlecitinib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ritlecitinib is mainly excreted through urine and feces. Approximately 66% and 20% of radiolabeled ritlecitinib are excreted in the urine and feces, respectively. Approximately 4% of the ritlecitinib dose is excreted unchanged drug in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Ritlecitinib has a terminal half-life that ranges from 1.3 to 2.3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ritlecitinib is predicted to have a blood clearance of 5.6 mL/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): During clinical trials, the highest single dose of ritlecitinib was 800 mg. No specific toxicities were identified at this dose, and the adverse reactions detected were comparable to those seen at lower doses. Pharmacokinetic studies indicate that in healthy adult volunteers given a single oral dose of 800 mg, more than 90% of ritlecitinib is expected to be eliminated within 48 hours. There is no specific antidote for overdose with ritlecitinib. In patients experiencing a ritlecitinib overdose, provide symptomatic and supportive treatment, and monitor for signs and symptoms of adverse reactions. In rats given 100 mg/kg/day of ritlecitinib (29 times the maximum recommended human dose based on AUC comparison), females had an increased incidence of combined benign and malignant thymomas, while males had a higher incidence of thyroid follicular adenomas and combined follicular adenomas and carcinomas. Ritlecitinib was negative in the bacterial reverse mutation assay and positive in an in vitro micronucleus assay in TK6 cells; however, mechanistic studies suggest that ritlecitinib is aneugenic and does not present a clinically relevant genotoxic concern. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Litfulo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ritlecitinib is a kinase inhibitor used to treat severe alopecia areata in adults and adolescents 12 years and older. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Ritonavir interact?

•Drug A: Abatacept •Drug B: Ritonavir •Severity: MODERATE •Description: The metabolism of Ritonavir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ritonavir is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. In the US, Europe, and Canada, ritonavir, in combination with nirmatrelvir, is indicated for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death. In Europe, this therapeutic indication is approved under conditional marketing authorization. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ritonavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Ritonavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs. Modern protease inhibitors require the use of low-dose ritonavir to boost pharmacokinetic exposure through inhibition of metabolism via the cytochrome P450 3A4 enzyme pathway. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ritonavic inhibits the HIV viral proteinase enzyme that normally cleaves the structural and replicative proteins that arise from major HIV genes, such as gag and pol. Gag encodes proteins involved in the core and the nucleocapsid, while pol encodes the the HIV reverse transcriptase, ribonuclease H, integrase, and protease. The pol -encoded proteins are initially translated in the form of a larger precursoe polypeptide, gag-pol, and needs to be cleaved by HIV protease to form other complement proteins. Ritonavir prevents the cleavage of the gag-pol polyprotein, which results in noninfectious, immature viral particles. Ritonavir is a potent inhibitor of cytochrome P450 CYP3A4 isoenzyme present both in the intestinal tract and liver. It is a type II ligand that perfectly fits into the CYP3A4 active site cavity and irreversibly binds to the heme iron via the thiazole nitrogen, which decreases the redox potential of the protein and precludes its reduction with the redox partner, cytochrome P450 reductase. Ritonavir may also play a role in limiting cellular transport and efflux of other protease inhibitors via the P-glycoprotein and MRP efflux channels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of ritonavir has not been determined. Following oral administration, peak concentrations are reached after approximately 2 hours and 4 hours (T max ) after dosing under fasting and non-fasting conditions, respectively. It should be noted that ritonavir capsules and tablets are not considered bioequivalent. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated volume of distribution of ritonavir is 0.41 ± 0.25 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ritonavir is highly protein-bound in plasma (~98-99%), primarily to albumin and alpha-1 acid glycoprotein over the standard concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ritonavir circulates in the plasma predominantly as unchanged drug. Five metabolites have been identified. The isopropylthiazole oxidation metabolite (M-2) is the major metabolite in low plasma concentrations and retains similar antiviral activity to unchanged ritonavir. The cytochrome P450 enzymes CYP3A and CYP2D6 are the enzymes primarily involved in the metabolism of ritonavir. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ritonavir is primarily eliminated in the feces. Following oral administration of a single 600mg dose of radiolabeled ritonavir, approximately 11.3 ± 2.8% of the dose was excreted into the urine, of which 3.5 ± 1.8% was unchanged parent drug. The same study found that 86.4 ± 2.9% of the dose was excreted in the feces, of which 33.8 ± 10.8% was unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The approximate half-life of ritonavir is 3-5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent oral clearance at steady-state is 8.8 ± 3.2 L/h. Renal clearance is minimal and estimated to be <0.1 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Human experience of acute overdose with ritonavir is limited. One patient in clinical trials took ritonavir 1500 mg/day for two days. The patient reported paresthesias which resolved after the dose was decreased. A post-marketing case of renal failure with eosinophilia has been reported with ritonavir overdose. The approximate lethal dose was found to be greater than 20 times the related human dose in rats and 10 times the related human dose in mice. Oral LD value in rats is >2500 mg/kg. Adverse effects of ritonavir may arise from drug-drug interactions. Other effects include hepatotoxicity, pancreatitis, and allergic reactions/hypersensitivity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kaletra, Norvir, Paxlovid, Viekira Pak •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ritonavir is an HIV protease inhibitor used in combination with other antivirals in the treatment of HIV infection.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ritonavir interact? Information: •Drug A: Abatacept •Drug B: Ritonavir •Severity: MODERATE •Description: The metabolism of Ritonavir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ritonavir is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. In the US, Europe, and Canada, ritonavir, in combination with nirmatrelvir, is indicated for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death. In Europe, this therapeutic indication is approved under conditional marketing authorization. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ritonavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Ritonavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs. Modern protease inhibitors require the use of low-dose ritonavir to boost pharmacokinetic exposure through inhibition of metabolism via the cytochrome P450 3A4 enzyme pathway. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ritonavic inhibits the HIV viral proteinase enzyme that normally cleaves the structural and replicative proteins that arise from major HIV genes, such as gag and pol. Gag encodes proteins involved in the core and the nucleocapsid, while pol encodes the the HIV reverse transcriptase, ribonuclease H, integrase, and protease. The pol -encoded proteins are initially translated in the form of a larger precursoe polypeptide, gag-pol, and needs to be cleaved by HIV protease to form other complement proteins. Ritonavir prevents the cleavage of the gag-pol polyprotein, which results in noninfectious, immature viral particles. Ritonavir is a potent inhibitor of cytochrome P450 CYP3A4 isoenzyme present both in the intestinal tract and liver. It is a type II ligand that perfectly fits into the CYP3A4 active site cavity and irreversibly binds to the heme iron via the thiazole nitrogen, which decreases the redox potential of the protein and precludes its reduction with the redox partner, cytochrome P450 reductase. Ritonavir may also play a role in limiting cellular transport and efflux of other protease inhibitors via the P-glycoprotein and MRP efflux channels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of ritonavir has not been determined. Following oral administration, peak concentrations are reached after approximately 2 hours and 4 hours (T max ) after dosing under fasting and non-fasting conditions, respectively. It should be noted that ritonavir capsules and tablets are not considered bioequivalent. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated volume of distribution of ritonavir is 0.41 ± 0.25 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ritonavir is highly protein-bound in plasma (~98-99%), primarily to albumin and alpha-1 acid glycoprotein over the standard concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ritonavir circulates in the plasma predominantly as unchanged drug. Five metabolites have been identified. The isopropylthiazole oxidation metabolite (M-2) is the major metabolite in low plasma concentrations and retains similar antiviral activity to unchanged ritonavir. The cytochrome P450 enzymes CYP3A and CYP2D6 are the enzymes primarily involved in the metabolism of ritonavir. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ritonavir is primarily eliminated in the feces. Following oral administration of a single 600mg dose of radiolabeled ritonavir, approximately 11.3 ± 2.8% of the dose was excreted into the urine, of which 3.5 ± 1.8% was unchanged parent drug. The same study found that 86.4 ± 2.9% of the dose was excreted in the feces, of which 33.8 ± 10.8% was unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The approximate half-life of ritonavir is 3-5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent oral clearance at steady-state is 8.8 ± 3.2 L/h. Renal clearance is minimal and estimated to be <0.1 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Human experience of acute overdose with ritonavir is limited. One patient in clinical trials took ritonavir 1500 mg/day for two days. The patient reported paresthesias which resolved after the dose was decreased. A post-marketing case of renal failure with eosinophilia has been reported with ritonavir overdose. The approximate lethal dose was found to be greater than 20 times the related human dose in rats and 10 times the related human dose in mice. Oral LD value in rats is >2500 mg/kg. Adverse effects of ritonavir may arise from drug-drug interactions. Other effects include hepatotoxicity, pancreatitis, and allergic reactions/hypersensitivity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kaletra, Norvir, Paxlovid, Viekira Pak •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ritonavir is an HIV protease inhibitor used in combination with other antivirals in the treatment of HIV infection. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Rituximab interact?

•Drug A: Abatacept •Drug B: Rituximab •Severity: MAJOR •Description: Rituximab may increase the immunosuppressive activities of Abatacept. •Extended Description: Concurrent use of rituximab and abatacept may result in an increased risk of serious infection due to the combined immunosuppressive effects of both therapies. According to the prescribing information for abatacept, there is insufficient evidence to assess the safety and efficacy of abatacept combined with other biologic therapies, and therefore such use is not recommended. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rituximab is indicated for the treatment of adult patients with relapsed or refractory, low-grade or follicular, CD20-positive, B-cell non-Hodgkin’s Lymphoma (NHL) as a single agent. Also, it is indicated for the treatment of adult patients with previously untreated follicular, CD20-positive, B-cell NHL in combination with first line chemotherapy and, in patients achieving a complete or partial response to a rituximab product in combination with chemotherapy, as single-agent maintenance therapy. Additionally, rituximab is indicated for the treatment of adult patients with non-progressing (including stable disease), low-grade, CD20-positive, B-cell NHL as a single agent after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy; and previously untreated diffuse large B-cell, CD20-positive NHL in combination with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or other anthracycline-based chemotherapy regimens. Rituximab, in combination with fludarabine and cyclophosphamide (FC), is indicated for the treatment of adult patients with previously untreated and previously treated CD20-positive chronic lymphocytic leukemia (CLL). In combination with methotrexate, rituximab is indicated for the treatment of adult patients with moderately-to severely-active rheumatoid arthritis who have had an inadequate response to one or more TNF antagonist therapies. Additionally, rituximab, in combination with glucocorticoids, is indicated for the treatment of adult and pediatric patients 2 years of age and older with Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA). RITUXAN (rituximab injection for intravenous use) is indicated for the treatment of pediatric patients aged 6 months and older with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), Burkitt-like lymphoma (BLL) or mature B-cell acute leukemia (B-AL) in combination with chemotherapy; as well as the treatment of adult patients with moderate to severe pemphigus vulgaris. These indications for RITUXAN are not included in the labels of rituximab biosimilar products (rituximab-arrx, rituximab-abbs, rituximab-pvvr). The combination product RITUXAN HYCELA (rituximab and hyaluronidase human injection, for subcutaneous use) is not indicated for the treatment of non-malignant conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rituximab is a chimeric murine/human monoclonal antibody that binds to the CD20 antigen. CD20 is predominantly expressed on the surface of pre-B and mature B-lymphocytes, allowing rituximab to target and promote lysis in this specific type of cells.. In Non-Hodgkin's Lymphoma patients, rituximab treatment depleted circulating and tissue-based B-cells. In a study that included 166 patients, CD19-positive B-cells were depleted within three weeks, and in 83% of patients, cell depletion lasted up to 6-9 months. B-cell levels started to recover at approximately 6 months and returned to normal 12 months after treatment was completed. Approximately 14% of Non-Hodgkin's Lymphoma patients had IgM or IgG serum levels below the normal range. Most rheumatoid arthritis (RA) patients treated with rituximab showed a near-complete depletion of peripheral B lymphocytes within 2 weeks after the first dose. Peripheral B-cell depletion was sustained for at least 6 months, and in approximately 4% of RA patients, peripheral B-cell depletion was sustained for more than 3 years after a single course of rituximab treatment. Total IgG, IgA, and, more specifically, IgM levels were lower 24 weeks after the first cycle of rituximab treatment (2.8%, 0.8% and 10% below the lower limit of normal, respectively). However, the clinical consequences of this decrease in immunoglobulin levels in RA patients are not clear at this time. Treatment with rituximab in patients with RA was also associated with a decreased level of inflammation markers. In patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) treated with rituximab, CD19 B-cells in peripheral blood were depleted to less than 10 cells/μl after the first two infusions. By month 6, approximately 84% of patients had the same level of peripheral blood CD19 B-cells, and by month 12, 81% of patients demonstrated signs of B-cell return with counts >10 cells/μL. By Month 18, the majority of patients (87%) had counts >10 cells/μL. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rituximab is a monoclonal antibody that targets CD20, an antigen expressed on the surface of pre-B and mature B-lymphocytes. About 85% of non-Hodgkin’s lymphoma (NHL) cases are B-cell lymphomas, characterized by the high expression of CD19, CD20 and CD22 cell surface antigens. CD20 is involved in cell cycle regulation, apoptosis and calcium signaling. By targeting CD20, rituximab promotes cell lysis while sparing hematopoietic and plasma cells without this surface antigen. It has been suggested that cell lysis mechanisms triggered by rituximab include complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Rituximab is part of the immunoglobulin G1 (IgG1) subclass of antibodies, and is formed by a murine variable region (Fab region) and a human constant region (Fc region). The Fab region gives rituximab its specificity for CD20, while the Fc region interacts with cell surface receptors to activate the immune system, leading to the depletion of circulating B lymphocytes. In regards to the mechanism of action in rheumatoid arthritis (RA), B-cells are thought to play a role in the pathogenesis of RA and the associated condition of chronic synovitis. B-cells may act at various sites in the autoimmune/inflammatory process through the production of rheumatoid factor (RF) and other autoantibodies, antigen presentation, T-cell activation, and the production of proinflammatory cytokines. The administration of rituximab in this condition has resulted in significant clinical and symptomatic improvements. Rituximab is also indicated for the treatment of granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), two conditions characterized by the presence of circulating antineutrophil cytoplasmic antibodies and increased B-cell activity. It has been suggested that rituximab depletes CD20 B-cells at a higher rate in GPA and MPA patients with high levels of Fc receptor-like 5 (FCRL5). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rituximab follows a linear pharmacokinetic model. In patients with non-Hodgkin’s lymphoma (NHL) administered 4 doses of 375 mg/m of rituximab (IV) weekly, detectable levels were observed 3-6 months after treatment completion. The pharmacokinetic profile of rituximab administered in combination with 6 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy was similar to the one observed when administered alone. In patients with rheumatoid arthritis (RA) administered 2 doses of 500 mg of rituximab, the C max of the first and second infusions were 157 (SD ± 46) and 183 (SD ± 55) mcg/mL. In patients administered 2 doses of 1,000 mg of rituximab, the C max of the first and second infusions were 318 (SD ± 86) and 381 (SD ± 98) mcg/mL. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the AUC 0-180 was 9787 µg/mL⋅day (range from 4838 to 20446 µg/mL⋅day). In adult patients given the same dose, the AUC 0-180 of rituximab was 10302 µg/mL⋅day (range from 3653 to 21874 µg/mL⋅day). The bioavailability of rituximab administered intravenously is expected to be close to 100%. Compared to rituximab administered intravenously, the bioavailability of RITUXAN HYCELA, a combination product of rituximab and hyaluronidase (human recombinant), is 64.6% in patients with follicular lymphoma and 63.4% in patients with chronic lymphocytic leukemia (CLL). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the volume of distribution of rituximab is 3.1 L. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the volume of distribution was 2.28 L (range from 1.43 to 3.17 L). In adult patients given the same dose, the volume of distribution was 3.12 L (range from 2.42 to 3.91 L). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab on days 1, 15, 168, and 182, the volume of distribution was 3.49 L (range from 2.48 to 5.22 L). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Not available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As a monoclonal antibody, rituximab is expected to be metabolized by proteases throughout the body. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monoclonal antibodies (mAb) such as rituximab trigger the formation of antidrug antibodies (ADAs) that form ADA-mAb immune complexes. The endogenous elimination of these immune complexes is mediated by the reticuloendothelial system, most likely via fragment crystallizable-gamma (Fcγ)-mediated endocytosis. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): In patients with non-Hodgkin's lymphoma (NHL) treated with rituximab once a week or once every three weeks (n=298), the median terminal elimination half-life was 22 days (range of 6.1-52 days). In patients with chronic lymphocytic leukemia (CLL) treated with rituximab (n=21), the estimated median terminal half-life was 32 days (range of 14-62 days). Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the mean terminal elimination half-life of rituximab is 18.0 days. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the terminal half-life was 22 days (range from 11 to 42 days). In adult patients given the same dose, the terminal half-life was 25 days (range from 11 to 52 days). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab, the terminal half-life was 21.1 days (range from 9.3 to 36.2 days) in the first infusion cycle (days 1 and 15), and 26.2 days (range from 16.4 to 42.8 days) in the second infusion cycle (days 168 and 182). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with non-Hodgkin’s lymphoma (NHL), those with higher CD19-positive cell counts or larger measurable tumor lesions at pretreatment had higher rituximab clearance. Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the clearance of rituximab is 0.335 L/day. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, clearance was 0.222 L/day (range from 0.0996 to 0.381 L/day). In adult patients given the same dose, clearance was 0.279 L/day (range from 0.113 to 0.653 L/day). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab, clearance was 0.30 L/day (range from 0.16 to 1.51 L/day) in the first infusion cycle (days 1 and 15), and 0.24 L/day (range from 0.13 to 0.45 L/day) in the second infusion cycle (days 168 and 182). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information regarding rituximab is not readily available. Patients experiencing an overdose are at an increased risk of severe adverse effects such as fatal infusion-related reactions and severe mucocutaneous reactions. Symptomatic and supportive measures are recommended. No long-term animal studies have been performed to establish the carcinogenic or mutagenic potential of rituximab or to determine potential effects on fertility in males or females. The maximum tolerated dose of rituximab in mice administered intraperitoneally is higher than 100 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): MabThera, Riabni, Rituxan, Rituxan Hycela, Ruxience, Truxima •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rituximab is a monoclonal anti-CD20 antibody used to treat non-Hodgkin's lymphoma, chronic lymphocytic leukemia, Wegener's granulomatosis, pemphigus vulgaris, and rheumatoid arthritis.

Concurrent use of rituximab and abatacept may result in an increased risk of serious infection due to the combined immunosuppressive effects of both therapies. According to the prescribing information for abatacept, there is insufficient evidence to assess the safety and efficacy of abatacept combined with other biologic therapies, and therefore such use is not recommended. The severity of the interaction is major.

Question: Does Abatacept and Rituximab interact? Information: •Drug A: Abatacept •Drug B: Rituximab •Severity: MAJOR •Description: Rituximab may increase the immunosuppressive activities of Abatacept. •Extended Description: Concurrent use of rituximab and abatacept may result in an increased risk of serious infection due to the combined immunosuppressive effects of both therapies. According to the prescribing information for abatacept, there is insufficient evidence to assess the safety and efficacy of abatacept combined with other biologic therapies, and therefore such use is not recommended. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rituximab is indicated for the treatment of adult patients with relapsed or refractory, low-grade or follicular, CD20-positive, B-cell non-Hodgkin’s Lymphoma (NHL) as a single agent. Also, it is indicated for the treatment of adult patients with previously untreated follicular, CD20-positive, B-cell NHL in combination with first line chemotherapy and, in patients achieving a complete or partial response to a rituximab product in combination with chemotherapy, as single-agent maintenance therapy. Additionally, rituximab is indicated for the treatment of adult patients with non-progressing (including stable disease), low-grade, CD20-positive, B-cell NHL as a single agent after first-line cyclophosphamide, vincristine, and prednisone (CVP) chemotherapy; and previously untreated diffuse large B-cell, CD20-positive NHL in combination with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or other anthracycline-based chemotherapy regimens. Rituximab, in combination with fludarabine and cyclophosphamide (FC), is indicated for the treatment of adult patients with previously untreated and previously treated CD20-positive chronic lymphocytic leukemia (CLL). In combination with methotrexate, rituximab is indicated for the treatment of adult patients with moderately-to severely-active rheumatoid arthritis who have had an inadequate response to one or more TNF antagonist therapies. Additionally, rituximab, in combination with glucocorticoids, is indicated for the treatment of adult and pediatric patients 2 years of age and older with Granulomatosis with Polyangiitis (GPA) (Wegener’s Granulomatosis) and Microscopic Polyangiitis (MPA). RITUXAN (rituximab injection for intravenous use) is indicated for the treatment of pediatric patients aged 6 months and older with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), Burkitt-like lymphoma (BLL) or mature B-cell acute leukemia (B-AL) in combination with chemotherapy; as well as the treatment of adult patients with moderate to severe pemphigus vulgaris. These indications for RITUXAN are not included in the labels of rituximab biosimilar products (rituximab-arrx, rituximab-abbs, rituximab-pvvr). The combination product RITUXAN HYCELA (rituximab and hyaluronidase human injection, for subcutaneous use) is not indicated for the treatment of non-malignant conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rituximab is a chimeric murine/human monoclonal antibody that binds to the CD20 antigen. CD20 is predominantly expressed on the surface of pre-B and mature B-lymphocytes, allowing rituximab to target and promote lysis in this specific type of cells.. In Non-Hodgkin's Lymphoma patients, rituximab treatment depleted circulating and tissue-based B-cells. In a study that included 166 patients, CD19-positive B-cells were depleted within three weeks, and in 83% of patients, cell depletion lasted up to 6-9 months. B-cell levels started to recover at approximately 6 months and returned to normal 12 months after treatment was completed. Approximately 14% of Non-Hodgkin's Lymphoma patients had IgM or IgG serum levels below the normal range. Most rheumatoid arthritis (RA) patients treated with rituximab showed a near-complete depletion of peripheral B lymphocytes within 2 weeks after the first dose. Peripheral B-cell depletion was sustained for at least 6 months, and in approximately 4% of RA patients, peripheral B-cell depletion was sustained for more than 3 years after a single course of rituximab treatment. Total IgG, IgA, and, more specifically, IgM levels were lower 24 weeks after the first cycle of rituximab treatment (2.8%, 0.8% and 10% below the lower limit of normal, respectively). However, the clinical consequences of this decrease in immunoglobulin levels in RA patients are not clear at this time. Treatment with rituximab in patients with RA was also associated with a decreased level of inflammation markers. In patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) treated with rituximab, CD19 B-cells in peripheral blood were depleted to less than 10 cells/μl after the first two infusions. By month 6, approximately 84% of patients had the same level of peripheral blood CD19 B-cells, and by month 12, 81% of patients demonstrated signs of B-cell return with counts >10 cells/μL. By Month 18, the majority of patients (87%) had counts >10 cells/μL. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rituximab is a monoclonal antibody that targets CD20, an antigen expressed on the surface of pre-B and mature B-lymphocytes. About 85% of non-Hodgkin’s lymphoma (NHL) cases are B-cell lymphomas, characterized by the high expression of CD19, CD20 and CD22 cell surface antigens. CD20 is involved in cell cycle regulation, apoptosis and calcium signaling. By targeting CD20, rituximab promotes cell lysis while sparing hematopoietic and plasma cells without this surface antigen. It has been suggested that cell lysis mechanisms triggered by rituximab include complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Rituximab is part of the immunoglobulin G1 (IgG1) subclass of antibodies, and is formed by a murine variable region (Fab region) and a human constant region (Fc region). The Fab region gives rituximab its specificity for CD20, while the Fc region interacts with cell surface receptors to activate the immune system, leading to the depletion of circulating B lymphocytes. In regards to the mechanism of action in rheumatoid arthritis (RA), B-cells are thought to play a role in the pathogenesis of RA and the associated condition of chronic synovitis. B-cells may act at various sites in the autoimmune/inflammatory process through the production of rheumatoid factor (RF) and other autoantibodies, antigen presentation, T-cell activation, and the production of proinflammatory cytokines. The administration of rituximab in this condition has resulted in significant clinical and symptomatic improvements. Rituximab is also indicated for the treatment of granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), two conditions characterized by the presence of circulating antineutrophil cytoplasmic antibodies and increased B-cell activity. It has been suggested that rituximab depletes CD20 B-cells at a higher rate in GPA and MPA patients with high levels of Fc receptor-like 5 (FCRL5). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rituximab follows a linear pharmacokinetic model. In patients with non-Hodgkin’s lymphoma (NHL) administered 4 doses of 375 mg/m of rituximab (IV) weekly, detectable levels were observed 3-6 months after treatment completion. The pharmacokinetic profile of rituximab administered in combination with 6 cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy was similar to the one observed when administered alone. In patients with rheumatoid arthritis (RA) administered 2 doses of 500 mg of rituximab, the C max of the first and second infusions were 157 (SD ± 46) and 183 (SD ± 55) mcg/mL. In patients administered 2 doses of 1,000 mg of rituximab, the C max of the first and second infusions were 318 (SD ± 86) and 381 (SD ± 98) mcg/mL. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the AUC 0-180 was 9787 µg/mL⋅day (range from 4838 to 20446 µg/mL⋅day). In adult patients given the same dose, the AUC 0-180 of rituximab was 10302 µg/mL⋅day (range from 3653 to 21874 µg/mL⋅day). The bioavailability of rituximab administered intravenously is expected to be close to 100%. Compared to rituximab administered intravenously, the bioavailability of RITUXAN HYCELA, a combination product of rituximab and hyaluronidase (human recombinant), is 64.6% in patients with follicular lymphoma and 63.4% in patients with chronic lymphocytic leukemia (CLL). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the volume of distribution of rituximab is 3.1 L. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the volume of distribution was 2.28 L (range from 1.43 to 3.17 L). In adult patients given the same dose, the volume of distribution was 3.12 L (range from 2.42 to 3.91 L). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab on days 1, 15, 168, and 182, the volume of distribution was 3.49 L (range from 2.48 to 5.22 L). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Not available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As a monoclonal antibody, rituximab is expected to be metabolized by proteases throughout the body. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monoclonal antibodies (mAb) such as rituximab trigger the formation of antidrug antibodies (ADAs) that form ADA-mAb immune complexes. The endogenous elimination of these immune complexes is mediated by the reticuloendothelial system, most likely via fragment crystallizable-gamma (Fcγ)-mediated endocytosis. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): In patients with non-Hodgkin's lymphoma (NHL) treated with rituximab once a week or once every three weeks (n=298), the median terminal elimination half-life was 22 days (range of 6.1-52 days). In patients with chronic lymphocytic leukemia (CLL) treated with rituximab (n=21), the estimated median terminal half-life was 32 days (range of 14-62 days). Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the mean terminal elimination half-life of rituximab is 18.0 days. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, the terminal half-life was 22 days (range from 11 to 42 days). In adult patients given the same dose, the terminal half-life was 25 days (range from 11 to 52 days). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab, the terminal half-life was 21.1 days (range from 9.3 to 36.2 days) in the first infusion cycle (days 1 and 15), and 26.2 days (range from 16.4 to 42.8 days) in the second infusion cycle (days 168 and 182). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with non-Hodgkin’s lymphoma (NHL), those with higher CD19-positive cell counts or larger measurable tumor lesions at pretreatment had higher rituximab clearance. Based on a pharmacokinetic analysis that included 2005 patients with rheumatoid arthritis (RA), the clearance of rituximab is 0.335 L/day. In pediatric patients (6-17 years old) with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) given four doses of 375 mg/m of rituximab intravenously once a week, clearance was 0.222 L/day (range from 0.0996 to 0.381 L/day). In adult patients given the same dose, clearance was 0.279 L/day (range from 0.113 to 0.653 L/day). In patients with pemphigus vulgaris given an intravenous infusion of 1000 mg of rituximab, clearance was 0.30 L/day (range from 0.16 to 1.51 L/day) in the first infusion cycle (days 1 and 15), and 0.24 L/day (range from 0.13 to 0.45 L/day) in the second infusion cycle (days 168 and 182). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information regarding rituximab is not readily available. Patients experiencing an overdose are at an increased risk of severe adverse effects such as fatal infusion-related reactions and severe mucocutaneous reactions. Symptomatic and supportive measures are recommended. No long-term animal studies have been performed to establish the carcinogenic or mutagenic potential of rituximab or to determine potential effects on fertility in males or females. The maximum tolerated dose of rituximab in mice administered intraperitoneally is higher than 100 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): MabThera, Riabni, Rituxan, Rituxan Hycela, Ruxience, Truxima •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rituximab is a monoclonal anti-CD20 antibody used to treat non-Hodgkin's lymphoma, chronic lymphocytic leukemia, Wegener's granulomatosis, pemphigus vulgaris, and rheumatoid arthritis. Output: Concurrent use of rituximab and abatacept may result in an increased risk of serious infection due to the combined immunosuppressive effects of both therapies. According to the prescribing information for abatacept, there is insufficient evidence to assess the safety and efficacy of abatacept combined with other biologic therapies, and therefore such use is not recommended. The severity of the interaction is major.

Does Abatacept and Rivaroxaban interact?

•Drug A: Abatacept •Drug B: Rivaroxaban •Severity: MODERATE •Description: The metabolism of Rivaroxaban can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rivaroxaban is indicated for the prevention of venous thromboembolic events (VTE) in patients who have undergone total hips replacements and total knee replacement surgery; prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation; treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE); to reduce risk of recurrent DVT and/or PE. Rivaroxaban is also indicated, in combination with aspirin, for reducing the risk of major cardiovascular events in patients with chronic coronary artery disease or peripheral artery disease. Its use is also not recommended in those with severe renal impairment (<30mL/min). Rivaroxaban is also indicated for the treatment and prevention of VTE in pediatric patients (from birth to 18 years of age) and for thromboprophylaxis in pediatric patients ≥2 years old with congenital heart disease following the Fontan procedure. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rivaroxaban is an anticoagulant which binds directly to factor Xa. Thereafter, it effectively blocks the amplification of the coagulation cascade, preventing the formation of thrombus. Rivaroxaban is a unqiue anticoagulant for two reasons. First of all, it is does not involve antithrombin III (ATIII) to exert its anticoagulant effects. Secondly, it is an oral agent whereas the widely used unfractionated heparin and low molecular weight heparins are for parenteral use only. Although the activated partial thromboplastin time (aPTT) and HepTest (a test developed to assay low molecular weight heparins) are prolonged in a dose-dependant manner, neither test is recommended for the assessment of the pharmacodynamic effects of rivaroxaban. Anti-Xa activity and inhibition of anti-Xa activity monitoring is also not recommended despite being influenced by rivaroxaban. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rivaroxaban competitively inhibits free and clot bound factor Xa. Factor Xa is needed to activate prothrombin (factor II) to thrombin (factor IIa). Thrombin is a serine protease that is required to activate fibrinogen to fibrin, which is the loose meshwork that completes the clotting process. Since one molecule of factor Xa can generate more than 1000 molecules of thrombin, selective inhibitors of factor Xa are profoundly useful in terminating the amplification of thrombin generation. The action of rivaroxaban is irreversible. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, rivaroxaban is rapidly absorbed and reaches peak plasma concentration in 2-4 hours. Bioavailability of the 10 mg dose is >80%. However, the 15-20 mg dose have a lower bioavailability if taken in the fasted state and consequently should be taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady state Vd is 50 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding is about 92% to 95% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Approximately two-thirds of the dose is metabolized. It is metabolized by CYP3A4, CYP3A5, CYP2J2 and CYP-independant mechanisms •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately two-thirds of rivaroxaban is excreted into urine (via active tubular secretion in which approximately 36% as unchanged drug and 30% as inactive metabolism). The remaining third of the administered dose is excreted via feces in which 7% is in the form of unchanged drug and 21% as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life is 5-9 hours in adults and 11-13 hours in the elderly. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance is approximately 10 L/h, so rivaroxaban is considered a drug with low clearance. Renal clearance is ~3-4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Excessive bleeding. Overdosages should be treated using activated charcoal and supportive measures such as mechanical compression and hemodynamic support. If bleeding is not controlled, the following procoagulants can be administered: activated prothrombin complex concentrate, prothrombin complex concentrate and recombinant factor VIIa. There is also a higher chance of post procedural hemorrhage compared to enoxaparin (1.55% vs. 1.39% respectively). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xarelto •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rivaroxaban is a factor Xa inhibitor used to treat deep vein thrombosis (DVT) and pulmonary embolism (PE). May also be used as thrombosis prophylaxis in specific situations.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rivaroxaban interact? Information: •Drug A: Abatacept •Drug B: Rivaroxaban •Severity: MODERATE •Description: The metabolism of Rivaroxaban can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rivaroxaban is indicated for the prevention of venous thromboembolic events (VTE) in patients who have undergone total hips replacements and total knee replacement surgery; prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation; treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE); to reduce risk of recurrent DVT and/or PE. Rivaroxaban is also indicated, in combination with aspirin, for reducing the risk of major cardiovascular events in patients with chronic coronary artery disease or peripheral artery disease. Its use is also not recommended in those with severe renal impairment (<30mL/min). Rivaroxaban is also indicated for the treatment and prevention of VTE in pediatric patients (from birth to 18 years of age) and for thromboprophylaxis in pediatric patients ≥2 years old with congenital heart disease following the Fontan procedure. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rivaroxaban is an anticoagulant which binds directly to factor Xa. Thereafter, it effectively blocks the amplification of the coagulation cascade, preventing the formation of thrombus. Rivaroxaban is a unqiue anticoagulant for two reasons. First of all, it is does not involve antithrombin III (ATIII) to exert its anticoagulant effects. Secondly, it is an oral agent whereas the widely used unfractionated heparin and low molecular weight heparins are for parenteral use only. Although the activated partial thromboplastin time (aPTT) and HepTest (a test developed to assay low molecular weight heparins) are prolonged in a dose-dependant manner, neither test is recommended for the assessment of the pharmacodynamic effects of rivaroxaban. Anti-Xa activity and inhibition of anti-Xa activity monitoring is also not recommended despite being influenced by rivaroxaban. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rivaroxaban competitively inhibits free and clot bound factor Xa. Factor Xa is needed to activate prothrombin (factor II) to thrombin (factor IIa). Thrombin is a serine protease that is required to activate fibrinogen to fibrin, which is the loose meshwork that completes the clotting process. Since one molecule of factor Xa can generate more than 1000 molecules of thrombin, selective inhibitors of factor Xa are profoundly useful in terminating the amplification of thrombin generation. The action of rivaroxaban is irreversible. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, rivaroxaban is rapidly absorbed and reaches peak plasma concentration in 2-4 hours. Bioavailability of the 10 mg dose is >80%. However, the 15-20 mg dose have a lower bioavailability if taken in the fasted state and consequently should be taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady state Vd is 50 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding is about 92% to 95% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Approximately two-thirds of the dose is metabolized. It is metabolized by CYP3A4, CYP3A5, CYP2J2 and CYP-independant mechanisms •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately two-thirds of rivaroxaban is excreted into urine (via active tubular secretion in which approximately 36% as unchanged drug and 30% as inactive metabolism). The remaining third of the administered dose is excreted via feces in which 7% is in the form of unchanged drug and 21% as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life is 5-9 hours in adults and 11-13 hours in the elderly. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance is approximately 10 L/h, so rivaroxaban is considered a drug with low clearance. Renal clearance is ~3-4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Excessive bleeding. Overdosages should be treated using activated charcoal and supportive measures such as mechanical compression and hemodynamic support. If bleeding is not controlled, the following procoagulants can be administered: activated prothrombin complex concentrate, prothrombin complex concentrate and recombinant factor VIIa. There is also a higher chance of post procedural hemorrhage compared to enoxaparin (1.55% vs. 1.39% respectively). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xarelto •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rivaroxaban is a factor Xa inhibitor used to treat deep vein thrombosis (DVT) and pulmonary embolism (PE). May also be used as thrombosis prophylaxis in specific situations. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Roflumilast interact?

•Drug A: Abatacept •Drug B: Roflumilast •Severity: MINOR •Description: Roflumilast may increase the immunosuppressive activities of Abatacept. •Extended Description: Roflumilast is an inhibitor of phosphodiesterase-4 (PDE4). Inhibition of PDE4 affects the migration and actions of pro-inflammatory cells including neutrophils, other leukocytes, T-lymphocytes, monocytes, macrophages, and fibroblasts. According to multiple product monographs for roflumilast , there is insufficient data regarding the safety of concomitant use of roflumilast with immunosuppressive agents. Therefore, the use of roflumilast with long-term immunosuppressive therapy is not recommended. The use of short term systemic corticosteroids with roflumilast may be appropriate. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral roflumilast is indicated to reduce the risk of COPD exacerbations in patients with severe COPD associated with chronic bronchitis and a history of exacerbations. Topical cream roflumilast is indicated to treat plaque psoriasis, including intertriginous areas, in patients 12 years of age and older, while topical foam roflumilast is indicated to treat seborrheic dermatitis in adult and pediatric patients 9 years of age and older.. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Roflumilast and its active metabolite, roflumilast N-oxide, increase cyclic adenosine-3′, 5′-monophosphate (cAMP) in affected cells by inhibiting PDE4. They are highly selective for PDE4 and are effectively inactive against PDEs 1, 2, 3, 5, and 7. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Roflumilast and its active metabolite (roflumilast N-oxide) are inhibitors of PDE4. Roflumilast and roflumilast N-oxide inhibition of PDE4 (a major cyclic 3′,5′-adenosine monophosphate (cyclic AMP) metabolizing enzyme) activity leads to accumulation of intracellular cyclic AMP. The specific mechanism(s) by which roflumilast exerts its therapeutic action is not well defined. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After a 500mcg dose, the bioavailability of roflumilast is about 80%. In the fasted state, maximum plasma concentrations are reached in 0.5 to 2 hours, while in the fed state, Cmax is reduced by 40%, Tmax is increased by one hour, and total absorption is unchanged. Applied topically, the mean systemic exposure for roflumilast and its N-oxide metabolite in adults was 72.7 ± 53.1 and 628 ± 648 h∙ng/mL, respectively. The mean systemic exposure for roflumilast and its N-oxide metabolite in adolescents was 25.1 ± 24.0 and 140 ± 179 h∙ng/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following a single oral dose of 500 mcg, the volume of distribution of roflumilast is approximately 2.9 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of roflumilast and its N-oxide metabolite is approximately 99% and 97%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Roflumilast is metabolized to roflumilast N-oxide, the active metabolite of roflumilast in humans, by CYP3A4 and CYP1A2. The N-oxide metabolite is less potent than its parent drug in regards to PDE4 inhibition, but its plasma AUC is approximately 10-fold greater. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Roflumilast is excreted 70% in the urine as roflumilast N-oxide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration, the plasma half-lives of roflumilast and roflumilast N-oxide are 17 hours and 30 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance of roflumilast following short-term intravenous infusion is approximately 9.6 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are no data regarding overdosage with orally administered roflumilast. Phase I studies in which roflumilast was administered at single doses up to 5000 mcg showed an increase in the incidence of headache, gastrointestinal disorders, dizziness, palpitations, lightheadedness, clamminess, and arterial hypotension. In the event of an overdose, administer support medical care as soon as possible. Hemodialysis is unlikely to be of benefit given the extensive protein binding of roflumilast. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Daliresp, Zoryve •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Roflumilast is a selective phosphodiesterase-4 inhibitor indicated to decrease the risk of exacerbations in patients with severe chronic obstructive pulmonary disease (COPD) and to treat plaque psoriasis.

Roflumilast is an inhibitor of phosphodiesterase-4 (PDE4). Inhibition of PDE4 affects the migration and actions of pro-inflammatory cells including neutrophils, other leukocytes, T-lymphocytes, monocytes, macrophages, and fibroblasts. According to multiple product monographs for roflumilast , there is insufficient data regarding the safety of concomitant use of roflumilast with immunosuppressive agents. Therefore, the use of roflumilast with long-term immunosuppressive therapy is not recommended. The use of short term systemic corticosteroids with roflumilast may be appropriate. The severity of the interaction is minor.

Question: Does Abatacept and Roflumilast interact? Information: •Drug A: Abatacept •Drug B: Roflumilast •Severity: MINOR •Description: Roflumilast may increase the immunosuppressive activities of Abatacept. •Extended Description: Roflumilast is an inhibitor of phosphodiesterase-4 (PDE4). Inhibition of PDE4 affects the migration and actions of pro-inflammatory cells including neutrophils, other leukocytes, T-lymphocytes, monocytes, macrophages, and fibroblasts. According to multiple product monographs for roflumilast , there is insufficient data regarding the safety of concomitant use of roflumilast with immunosuppressive agents. Therefore, the use of roflumilast with long-term immunosuppressive therapy is not recommended. The use of short term systemic corticosteroids with roflumilast may be appropriate. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral roflumilast is indicated to reduce the risk of COPD exacerbations in patients with severe COPD associated with chronic bronchitis and a history of exacerbations. Topical cream roflumilast is indicated to treat plaque psoriasis, including intertriginous areas, in patients 12 years of age and older, while topical foam roflumilast is indicated to treat seborrheic dermatitis in adult and pediatric patients 9 years of age and older.. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Roflumilast and its active metabolite, roflumilast N-oxide, increase cyclic adenosine-3′, 5′-monophosphate (cAMP) in affected cells by inhibiting PDE4. They are highly selective for PDE4 and are effectively inactive against PDEs 1, 2, 3, 5, and 7. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Roflumilast and its active metabolite (roflumilast N-oxide) are inhibitors of PDE4. Roflumilast and roflumilast N-oxide inhibition of PDE4 (a major cyclic 3′,5′-adenosine monophosphate (cyclic AMP) metabolizing enzyme) activity leads to accumulation of intracellular cyclic AMP. The specific mechanism(s) by which roflumilast exerts its therapeutic action is not well defined. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After a 500mcg dose, the bioavailability of roflumilast is about 80%. In the fasted state, maximum plasma concentrations are reached in 0.5 to 2 hours, while in the fed state, Cmax is reduced by 40%, Tmax is increased by one hour, and total absorption is unchanged. Applied topically, the mean systemic exposure for roflumilast and its N-oxide metabolite in adults was 72.7 ± 53.1 and 628 ± 648 h∙ng/mL, respectively. The mean systemic exposure for roflumilast and its N-oxide metabolite in adolescents was 25.1 ± 24.0 and 140 ± 179 h∙ng/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following a single oral dose of 500 mcg, the volume of distribution of roflumilast is approximately 2.9 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of roflumilast and its N-oxide metabolite is approximately 99% and 97%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Roflumilast is metabolized to roflumilast N-oxide, the active metabolite of roflumilast in humans, by CYP3A4 and CYP1A2. The N-oxide metabolite is less potent than its parent drug in regards to PDE4 inhibition, but its plasma AUC is approximately 10-fold greater. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Roflumilast is excreted 70% in the urine as roflumilast N-oxide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration, the plasma half-lives of roflumilast and roflumilast N-oxide are 17 hours and 30 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance of roflumilast following short-term intravenous infusion is approximately 9.6 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are no data regarding overdosage with orally administered roflumilast. Phase I studies in which roflumilast was administered at single doses up to 5000 mcg showed an increase in the incidence of headache, gastrointestinal disorders, dizziness, palpitations, lightheadedness, clamminess, and arterial hypotension. In the event of an overdose, administer support medical care as soon as possible. Hemodialysis is unlikely to be of benefit given the extensive protein binding of roflumilast. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Daliresp, Zoryve •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Roflumilast is a selective phosphodiesterase-4 inhibitor indicated to decrease the risk of exacerbations in patients with severe chronic obstructive pulmonary disease (COPD) and to treat plaque psoriasis. Output: Roflumilast is an inhibitor of phosphodiesterase-4 (PDE4). Inhibition of PDE4 affects the migration and actions of pro-inflammatory cells including neutrophils, other leukocytes, T-lymphocytes, monocytes, macrophages, and fibroblasts. According to multiple product monographs for roflumilast , there is insufficient data regarding the safety of concomitant use of roflumilast with immunosuppressive agents. Therefore, the use of roflumilast with long-term immunosuppressive therapy is not recommended. The use of short term systemic corticosteroids with roflumilast may be appropriate. The severity of the interaction is minor.

Does Abatacept and Romidepsin interact?

•Drug A: Abatacept •Drug B: Romidepsin •Severity: MAJOR •Description: The metabolism of Romidepsin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Romidepsin is indicated for the treatment of cutaneous T-cell lymphoma (CTCL) in adult patients who have received at least one prior systemic therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Romidepsin is a prodrug, where it becomes active once taken up into the cell. The active metabolite has a free thiol group, which interacts with zinc ions in the active site of class 1 and 2 HDAC enzymes, resulting in inhibition of its enzymatic activity. Certain tumors have over expressed HDACs and downregulated/mutated histone acetyltransferases. This imbalance of HDAC relative to histone acetyltransferase can lead to a decrease in regulatory genes, ensuing tumorigenesis. Inhibition of HDAC may restore normal gene expression in cancer cells and result in cell cycle arrest and apoptosis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Romidepsin exhibited linear pharmacokinetics at standard doses. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 44.5L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Highly protein bound in plasma (92%-94%) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Romidepsin undergoes extensive hepatic metabolism in vitro primarily by CYP3A4 with minor contribution from CYP3A5, CYP1A1, CYP2B6 and CYP2C19. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 3 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 8.4L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Risk factor D in pregnancy. It is not known if romidepsin is excreted in breast milk. Due to the potential for serious adverse reactions in the nursing infant, the manufacturer recommends a decision be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of treatment to the mother. The majority of patients receiving romidepsin experience nausea, vomiting, and anorexia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Istodax •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Romidepsin is a histone deacetylase (HDAC) inhibitor used to treat cutaneous T-cell lymphoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Romidepsin interact? Information: •Drug A: Abatacept •Drug B: Romidepsin •Severity: MAJOR •Description: The metabolism of Romidepsin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Romidepsin is indicated for the treatment of cutaneous T-cell lymphoma (CTCL) in adult patients who have received at least one prior systemic therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Romidepsin is a prodrug, where it becomes active once taken up into the cell. The active metabolite has a free thiol group, which interacts with zinc ions in the active site of class 1 and 2 HDAC enzymes, resulting in inhibition of its enzymatic activity. Certain tumors have over expressed HDACs and downregulated/mutated histone acetyltransferases. This imbalance of HDAC relative to histone acetyltransferase can lead to a decrease in regulatory genes, ensuing tumorigenesis. Inhibition of HDAC may restore normal gene expression in cancer cells and result in cell cycle arrest and apoptosis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Romidepsin exhibited linear pharmacokinetics at standard doses. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 44.5L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Highly protein bound in plasma (92%-94%) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Romidepsin undergoes extensive hepatic metabolism in vitro primarily by CYP3A4 with minor contribution from CYP3A5, CYP1A1, CYP2B6 and CYP2C19. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 3 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 8.4L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Risk factor D in pregnancy. It is not known if romidepsin is excreted in breast milk. Due to the potential for serious adverse reactions in the nursing infant, the manufacturer recommends a decision be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of treatment to the mother. The majority of patients receiving romidepsin experience nausea, vomiting, and anorexia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Istodax •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Romidepsin is a histone deacetylase (HDAC) inhibitor used to treat cutaneous T-cell lymphoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Ropeginterferon alfa-2b interact?

•Drug A: Abatacept •Drug B: Ropeginterferon alfa-2b •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ropeginterferon alfa-2b. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ropeginterferon alfa-2b is indicated for the treatment of adult patients with polycythemia vera. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ropeginterferon alfa-2b acts through the interferon-alpha/beta receptor to initiate downstream JAK/STAT signalling leading to its therapeutic effects. Like other interferon alfa products, ropeginterferon alfa-2b may cause various toxicities, including endocrine, cardiovascular, pulmonary, ophthalmologic, dental/periodontal, renal, and dermatological toxicity. In addition, interferon alfa has been associated with hepatotoxicity, including increases in serum ALT, AST, GGT, and bilirubin; ropeginterferon alfa-2b is contraindicated in patients with moderate to severe (Child-Pugh B or C) hepatic impairment. Pancreatitis and colitis, including fatal ulcerative/hemorrhagic/ischemic colitis, have occurred in patients treated with interferon alfa. Significant toxicity of any kind may require treatment discontinuation. Interferon alfa treatment has decreased peripheral blood counts, including thrombocytopenia and leukopenia, and altered lipid levels, including hyperlipidemia, hypertriglyceridemia, and dyslipidemia. Hypersensitivity reactions, including anaphylaxis, may occur; ropeginterferon alfa-2b is contraindicated in hypersensitive patients and those with known hypersensitivity to other interferons. Life-threatening or fatal neuropsychiatric reactions may occur, including in patients without prior history; ropeginterferon alfa-2b is contraindicated in patients with a history of severe psychiatric disorders. Finally, ropeginterferon alfa-2b can cause fetal harm and should be used with caution in females of reproductive potential. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Polycythemia vera (PV) is the most common Philadelphia chromosome-negative myeloproliferative neoplasm (MPN), which also includes essential thrombocytopenia and myelofibrosis. PV is characterized by increased hematocrit and platelet/leukocyte counts, an increased risk for hemorrhage and thromboembolic events, and a long-term propensity for myelofibrosis and leukemia. The main driver mutation, JAK2 V617F, is present in >95% of PV patients and results in constitutive JAK/STAT signalling; other exon 12 mutations in JAK2 may also result in PV. PV results in clonal hematopoietic stem cells, such that they form endogenous erythroid colonies (EECs) in vitro. Interferon alfa-2b has been used for decades in PV despite the lack of formal approval. Although the mechanism of action is unclear, interferon alfa-2b is known to bind the interferon-alpha/beta receptor (IFNAR) and activate downstream JAK/STAT signalling. The overall result is a series of anti-proliferative, anti-angiogenic, pro-apoptotic, and immunomodulatory effects, including augmenting T-cell, macrophage, and natural killer cells. Interestingly, in vitro studies have revealed that ropeginterferon alfa-2b is specific to some extent for JAK2 -mutant EECs, a result that is in line with the reduced allelic burden observed in clinical trials. Partial and complete molecular and hematological responses have been achieved with ropeginterferon alfa-2b. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In patients with polycythemia vera on a two-week dosing interval, the estimated steady-state C min was 1.4-12 ng/mL, C max was 4.4-31 ng/mL, and AUC was 1011-7809 ng*h/mL. The estimated geometric mean (%CV) of the absorption rate constant if 0.12 day (27%) and the estimated steady-state C max occurs between 2-5 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ropeginterferon alfa-2b has an estimated geometric mean apparent volume of distribution (%CV) of 4.8 L (21%) in polycythemia vera patients. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropeginterferon alfa-2b is expected to be catabolized by various proteolytic enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ropeginterferon alfa-2b is expected to be eliminated predominantly by hepatic metabolism. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Ropeginterferon alfa-2b administered to polycythemia vera patients over a dose range of 100-500 μg has a half-life of approximately seven days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ropeginterferon alfa-2b administered to polycythemia vera patients over a dose range of 100-500 μg has a clearance of 1.7-2.5 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Ropeginterferon alfa-2b overdose may present with influenza-like symptoms or other adverse reactions. As there is no known antidote, symptomatic and supportive care should be administered in the result of an overdose. Ropeginterferon alfa-2b is not mutagenic in standard assays but has not been tested for carcinogenic potential. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Besremi •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropeginterferon alfa-2b is a mono-pegylated type I interferon used to treat polycythemia vera.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Ropeginterferon alfa-2b interact? Information: •Drug A: Abatacept •Drug B: Ropeginterferon alfa-2b •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Ropeginterferon alfa-2b. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ropeginterferon alfa-2b is indicated for the treatment of adult patients with polycythemia vera. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ropeginterferon alfa-2b acts through the interferon-alpha/beta receptor to initiate downstream JAK/STAT signalling leading to its therapeutic effects. Like other interferon alfa products, ropeginterferon alfa-2b may cause various toxicities, including endocrine, cardiovascular, pulmonary, ophthalmologic, dental/periodontal, renal, and dermatological toxicity. In addition, interferon alfa has been associated with hepatotoxicity, including increases in serum ALT, AST, GGT, and bilirubin; ropeginterferon alfa-2b is contraindicated in patients with moderate to severe (Child-Pugh B or C) hepatic impairment. Pancreatitis and colitis, including fatal ulcerative/hemorrhagic/ischemic colitis, have occurred in patients treated with interferon alfa. Significant toxicity of any kind may require treatment discontinuation. Interferon alfa treatment has decreased peripheral blood counts, including thrombocytopenia and leukopenia, and altered lipid levels, including hyperlipidemia, hypertriglyceridemia, and dyslipidemia. Hypersensitivity reactions, including anaphylaxis, may occur; ropeginterferon alfa-2b is contraindicated in hypersensitive patients and those with known hypersensitivity to other interferons. Life-threatening or fatal neuropsychiatric reactions may occur, including in patients without prior history; ropeginterferon alfa-2b is contraindicated in patients with a history of severe psychiatric disorders. Finally, ropeginterferon alfa-2b can cause fetal harm and should be used with caution in females of reproductive potential. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Polycythemia vera (PV) is the most common Philadelphia chromosome-negative myeloproliferative neoplasm (MPN), which also includes essential thrombocytopenia and myelofibrosis. PV is characterized by increased hematocrit and platelet/leukocyte counts, an increased risk for hemorrhage and thromboembolic events, and a long-term propensity for myelofibrosis and leukemia. The main driver mutation, JAK2 V617F, is present in >95% of PV patients and results in constitutive JAK/STAT signalling; other exon 12 mutations in JAK2 may also result in PV. PV results in clonal hematopoietic stem cells, such that they form endogenous erythroid colonies (EECs) in vitro. Interferon alfa-2b has been used for decades in PV despite the lack of formal approval. Although the mechanism of action is unclear, interferon alfa-2b is known to bind the interferon-alpha/beta receptor (IFNAR) and activate downstream JAK/STAT signalling. The overall result is a series of anti-proliferative, anti-angiogenic, pro-apoptotic, and immunomodulatory effects, including augmenting T-cell, macrophage, and natural killer cells. Interestingly, in vitro studies have revealed that ropeginterferon alfa-2b is specific to some extent for JAK2 -mutant EECs, a result that is in line with the reduced allelic burden observed in clinical trials. Partial and complete molecular and hematological responses have been achieved with ropeginterferon alfa-2b. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In patients with polycythemia vera on a two-week dosing interval, the estimated steady-state C min was 1.4-12 ng/mL, C max was 4.4-31 ng/mL, and AUC was 1011-7809 ng*h/mL. The estimated geometric mean (%CV) of the absorption rate constant if 0.12 day (27%) and the estimated steady-state C max occurs between 2-5 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ropeginterferon alfa-2b has an estimated geometric mean apparent volume of distribution (%CV) of 4.8 L (21%) in polycythemia vera patients. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropeginterferon alfa-2b is expected to be catabolized by various proteolytic enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ropeginterferon alfa-2b is expected to be eliminated predominantly by hepatic metabolism. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Ropeginterferon alfa-2b administered to polycythemia vera patients over a dose range of 100-500 μg has a half-life of approximately seven days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ropeginterferon alfa-2b administered to polycythemia vera patients over a dose range of 100-500 μg has a clearance of 1.7-2.5 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Ropeginterferon alfa-2b overdose may present with influenza-like symptoms or other adverse reactions. As there is no known antidote, symptomatic and supportive care should be administered in the result of an overdose. Ropeginterferon alfa-2b is not mutagenic in standard assays but has not been tested for carcinogenic potential. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Besremi •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropeginterferon alfa-2b is a mono-pegylated type I interferon used to treat polycythemia vera. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Ropinirole interact?

•Drug A: Abatacept •Drug B: Ropinirole •Severity: MODERATE •Description: The metabolism of Ropinirole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of the signs and symptoms of Parkinson's disease and for the treatment of primary moderate-severe restless legs syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Effects on Parkinson's and restless leg syndrome This drug promotes the relief or improvement of symptoms of Parkinson's or restless leg syndrome by stimulatory actions on dopamine receptors, which regulate movement. Effects on blood pressure Clinical experience with dopamine agonists, including ropinirole, suggests an association with impaired abilities in regulating blood pressure with resulting orthostatic hypotension, especially with patients undergoing dose escalation. In some patients in clinical studies, blood pressure changes were associated with orthostatic symptoms, bradycardia, and, in one case in a healthy volunteer, transient sinus arrest accompanied by syncope. The mechanism of orthostatic hypotension caused by ropinirole is assumed to be due to a D2-mediated blunting of noradrenergic response to a standing position, followed by a decrease in peripheral vascular resistance. Nausea is also a frequent symptom which accompanies orthostatic signs and symptoms. Effects on prolactin At oral doses as low as 0.2 mg, ropinirole suppressed serum prolactin concentrations in healthy male volunteers. Ropinirole had no dose-related effect on ECG wave form and rhythm in young, healthy, male volunteers in the range of 0.01 to 2.5 mg. Effects on QT interval Ropinirole had no dose- or exposure-related effect on average QT intervals in healthy male and female volunteers at doses up to 4 mg/day. The effect of ropinirole on QTc intervals at higher exposures reached either due to drug interactions, hepatic dysfunction, or at higher doses has not been adequately evaluated. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ropinirole is a non-ergoline dopamine agonist. Ropinirole has the highest affinity at the D3 receptors, which are concentrated in the limbic areas of the brain and may be responsible for some of the neuropsychiatric effects. The exact mechanism of action of ropinirole as a treatment for Parkinson’s disease is unknown, however, it is believed to be related to its ability to selectively stimulate dopamine D2 receptors within the caudate-putamen system in the brain. This system affects body movement. Negligible affinity is seen for ropinirole at α2 adrenoreceptors in the periphery and 5HT-1 receptor. Ropinirole has no affinity at the D1-like receptors, benzodiazepine or GABA receptors. The precise mechanism of action of ropinirole as a treatment for Restless Legs Syndrome is unknown, however, it is believed to be related to its ability to stimulate dopamine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ropinirole is rapidly absorbed after oral administration, reaching peak concentration in approximately 1 to 2 hours,. Absolute bioavailability was 45% to 55%, suggesting approximately 50% hepatic first-pass effect. The bioavailability of ropinirole prolonged release compared to the immediate release tablets is about 100%. Ingestion of food does not affect the absorption of ropinirole, although its Tmax was increased by 2.5 hours and its Cmax was reduced by approximately 25% when the drug is taken with a high-fat meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ropinirole is found to be widely distributed throughout the body, with an apparent volume of distribution of 7.5 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40% bound to plasma proteins with a blood-to-plasma ratio of 1:1. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropinirole is heavily metabolized by the liver. The most important metabolic pathways are N­ despropylation and hydroxylation to form the N-despropyl metabolite and hydroxy metabolites, both of which are inactive. The N-despropyl metabolite is then converted to carbamyl glucuronide, carboxylic acid, and N-despropyl hydroxy metabolites. Following this process, the hydroxy metabolite of ropinirole is glucuronidated at a rapid rate. In vitro studies show that the major cytochrome P450 enzyme involved in the metabolism of ropinirole is CYP1A2,. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The majority of the absorbed dose is cleared by the liver. In clinical trials, more than 88% of a radiolabeled dose was recovered in urine. Less than 10% of the administered dose is excreted as unchanged drug in urine. N-despropyl ropinirole is the major metabolite found in the urine (40%), followed by the carboxylic acid metabolite (10%), and the glucuronide of the hydroxy metabolite (10%). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 6 hours,. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of ropinirole after oral administration is 47 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose Symptoms of overdose include agitation, chest pain, confusion, drowsiness, facial muscle movements, grogginess, increased jerkiness of movement, symptoms of low blood pressure (dizziness, light-headedness)upon standing, nausea, and vomiting. Carcinogenicity Two-year carcinogenicity studies of ropinirole were performed on animal models at oral doses of 5, 15, and 50 mg/kg/day and in rats at oral doses of 1.5, 15, and 50 mg/kg/day. There was an increase in testicular Leydig cell adenomas at all doses tested in rats. The hormonal mechanisms thought to be involved in the development of these tumors in rats are not considered relevant to humans. In mice, there was an increase in benign uterine endometrial polyps at a dose of 50 mg/kg/day. The highest dose not associated with this observation (15 mg/kg/day) is three times the maximum recommended human dose on a mg/m2 basis. Mutagenesis Ropinirole was not found to be mutagenic or clastogenic during in vitro assays, or in the in vivo mouse micronucleus test. Effects on reproduction When given to female rats prior to and during mating and throughout pregnancy, ropinirole led to disruption of implantation at oral doses of 20 mg/kg/day (8 times the MRHD on a mg/m2 basis) or higher. This effect in rats is believed to be due to the prolactin-lowering effects of ropinirole. Use in Pregnancy Pregnancy Category C. There are no sufficient and well-controlled studies done in pregnant women. In animal reproduction studies, ropinirole has demonstrated adverse effects on embryo-fetal development, including teratogenicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Requip •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropinirole is a non-ergoline dopamine agonist used to treat the symptoms of Parkinson's disease and Restless Legs Syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ropinirole interact? Information: •Drug A: Abatacept •Drug B: Ropinirole •Severity: MODERATE •Description: The metabolism of Ropinirole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of the signs and symptoms of Parkinson's disease and for the treatment of primary moderate-severe restless legs syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Effects on Parkinson's and restless leg syndrome This drug promotes the relief or improvement of symptoms of Parkinson's or restless leg syndrome by stimulatory actions on dopamine receptors, which regulate movement. Effects on blood pressure Clinical experience with dopamine agonists, including ropinirole, suggests an association with impaired abilities in regulating blood pressure with resulting orthostatic hypotension, especially with patients undergoing dose escalation. In some patients in clinical studies, blood pressure changes were associated with orthostatic symptoms, bradycardia, and, in one case in a healthy volunteer, transient sinus arrest accompanied by syncope. The mechanism of orthostatic hypotension caused by ropinirole is assumed to be due to a D2-mediated blunting of noradrenergic response to a standing position, followed by a decrease in peripheral vascular resistance. Nausea is also a frequent symptom which accompanies orthostatic signs and symptoms. Effects on prolactin At oral doses as low as 0.2 mg, ropinirole suppressed serum prolactin concentrations in healthy male volunteers. Ropinirole had no dose-related effect on ECG wave form and rhythm in young, healthy, male volunteers in the range of 0.01 to 2.5 mg. Effects on QT interval Ropinirole had no dose- or exposure-related effect on average QT intervals in healthy male and female volunteers at doses up to 4 mg/day. The effect of ropinirole on QTc intervals at higher exposures reached either due to drug interactions, hepatic dysfunction, or at higher doses has not been adequately evaluated. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ropinirole is a non-ergoline dopamine agonist. Ropinirole has the highest affinity at the D3 receptors, which are concentrated in the limbic areas of the brain and may be responsible for some of the neuropsychiatric effects. The exact mechanism of action of ropinirole as a treatment for Parkinson’s disease is unknown, however, it is believed to be related to its ability to selectively stimulate dopamine D2 receptors within the caudate-putamen system in the brain. This system affects body movement. Negligible affinity is seen for ropinirole at α2 adrenoreceptors in the periphery and 5HT-1 receptor. Ropinirole has no affinity at the D1-like receptors, benzodiazepine or GABA receptors. The precise mechanism of action of ropinirole as a treatment for Restless Legs Syndrome is unknown, however, it is believed to be related to its ability to stimulate dopamine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ropinirole is rapidly absorbed after oral administration, reaching peak concentration in approximately 1 to 2 hours,. Absolute bioavailability was 45% to 55%, suggesting approximately 50% hepatic first-pass effect. The bioavailability of ropinirole prolonged release compared to the immediate release tablets is about 100%. Ingestion of food does not affect the absorption of ropinirole, although its Tmax was increased by 2.5 hours and its Cmax was reduced by approximately 25% when the drug is taken with a high-fat meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Ropinirole is found to be widely distributed throughout the body, with an apparent volume of distribution of 7.5 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40% bound to plasma proteins with a blood-to-plasma ratio of 1:1. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropinirole is heavily metabolized by the liver. The most important metabolic pathways are N­ despropylation and hydroxylation to form the N-despropyl metabolite and hydroxy metabolites, both of which are inactive. The N-despropyl metabolite is then converted to carbamyl glucuronide, carboxylic acid, and N-despropyl hydroxy metabolites. Following this process, the hydroxy metabolite of ropinirole is glucuronidated at a rapid rate. In vitro studies show that the major cytochrome P450 enzyme involved in the metabolism of ropinirole is CYP1A2,. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The majority of the absorbed dose is cleared by the liver. In clinical trials, more than 88% of a radiolabeled dose was recovered in urine. Less than 10% of the administered dose is excreted as unchanged drug in urine. N-despropyl ropinirole is the major metabolite found in the urine (40%), followed by the carboxylic acid metabolite (10%), and the glucuronide of the hydroxy metabolite (10%). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 6 hours,. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of ropinirole after oral administration is 47 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose Symptoms of overdose include agitation, chest pain, confusion, drowsiness, facial muscle movements, grogginess, increased jerkiness of movement, symptoms of low blood pressure (dizziness, light-headedness)upon standing, nausea, and vomiting. Carcinogenicity Two-year carcinogenicity studies of ropinirole were performed on animal models at oral doses of 5, 15, and 50 mg/kg/day and in rats at oral doses of 1.5, 15, and 50 mg/kg/day. There was an increase in testicular Leydig cell adenomas at all doses tested in rats. The hormonal mechanisms thought to be involved in the development of these tumors in rats are not considered relevant to humans. In mice, there was an increase in benign uterine endometrial polyps at a dose of 50 mg/kg/day. The highest dose not associated with this observation (15 mg/kg/day) is three times the maximum recommended human dose on a mg/m2 basis. Mutagenesis Ropinirole was not found to be mutagenic or clastogenic during in vitro assays, or in the in vivo mouse micronucleus test. Effects on reproduction When given to female rats prior to and during mating and throughout pregnancy, ropinirole led to disruption of implantation at oral doses of 20 mg/kg/day (8 times the MRHD on a mg/m2 basis) or higher. This effect in rats is believed to be due to the prolactin-lowering effects of ropinirole. Use in Pregnancy Pregnancy Category C. There are no sufficient and well-controlled studies done in pregnant women. In animal reproduction studies, ropinirole has demonstrated adverse effects on embryo-fetal development, including teratogenicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Requip •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropinirole is a non-ergoline dopamine agonist used to treat the symptoms of Parkinson's disease and Restless Legs Syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Ropivacaine interact?

•Drug A: Abatacept •Drug B: Ropivacaine •Severity: MODERATE •Description: The metabolism of Ropivacaine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ropivacaine is indicated in adult patients for the induction of regional or local anesthesia for surgery or acute pain management. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In contrast to most other local anesthetics, the presence of epinephrine does not affect the time of onset, duration of action, or the systemic absorption of ropivacaine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Local anesthetics like ropivacaine block the generation and conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Specifically, they block the sodium channel and decrease chances of depolarization and consequent action potentials. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ropivacaine pharmacokinetics are highly dependent on the dose, route of administration, and patient condition. Following epidural administration ropivacaine undergoes complete and biphasic absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following intravascular infusion, ropivacaine has a steady-state volume of distribution of 41 ± 7 liters. Ropivacaine is able to readily cross the placenta. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ropivacaine is 94% protein-bound in plasma, primarily to α1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropivacaine undergoes extensive metabolism, primarily via CYP1A2-mediated aromatic hydroxylation to 3-OH-ropivacaine. The main metabolites excreted in the urine are the N-dealkylated metabolite (PPX) and 3-OH-ropivacaine. Other identified metabolites include 4-OH-ropivacaine, the 3-hydroxy-N-dealkylated (3-OH-PPX) and 4-hydroxy-N-dealkylated (4-OH-PPX) metabolites, and 2-hydroxy-methyl-ropivacaine (which has been identified but not quantified). Unbound PPX, 3-hydroxy-, and 4-hydroxy-ropivacaine have demonstrated pharmacological activity in animal models less than that of ropivacaine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following intravenous administration, 86% of the administered dose of ropivacaine is excreted in the urine, 1% of which comprises unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of ropivacaine is 1.8 ± 0.7 hours after intravascular administration and 4.2 ± 1 hour after epidural administration. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following intravenous administration, ropivacaine has a mean plasma clearance of 387 ± 107 mL/min, an unbound plasma clearance of 7.2 ± 1.6 L/min, and a renal clearance of 1 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): High systemic doses of ropivacaine can result in central nervous system (CNS) and cardiovascular effects, with the CNS effects usually occurring at lower blood plasma concentrations and additional cardiovascular effects occurring at higher concentrations (although cardiovascular collapse may occur at lower concentrations). CNS effects include CNS excitation involving nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, and seizures. CNS depressant effects may follow, associated with drowsiness, loss of consciousness, respiratory depression and apnea. Cardiovascular events may be caused by hypoxemia secondary to respiratory depression and include hypotension, bradycardia, arrhythmias, and/or cardiac arrest. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Naropin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-ropivacaine Ropivacaina Ropivacaine Ropivacainum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropivacaine is an amide-type local anesthetic used for local or regional anesthesia during surgery and for short-term management of acute pain.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ropivacaine interact? Information: •Drug A: Abatacept •Drug B: Ropivacaine •Severity: MODERATE •Description: The metabolism of Ropivacaine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ropivacaine is indicated in adult patients for the induction of regional or local anesthesia for surgery or acute pain management. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In contrast to most other local anesthetics, the presence of epinephrine does not affect the time of onset, duration of action, or the systemic absorption of ropivacaine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Local anesthetics like ropivacaine block the generation and conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse, and by reducing the rate of rise of the action potential. Specifically, they block the sodium channel and decrease chances of depolarization and consequent action potentials. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ropivacaine pharmacokinetics are highly dependent on the dose, route of administration, and patient condition. Following epidural administration ropivacaine undergoes complete and biphasic absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following intravascular infusion, ropivacaine has a steady-state volume of distribution of 41 ± 7 liters. Ropivacaine is able to readily cross the placenta. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ropivacaine is 94% protein-bound in plasma, primarily to α1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ropivacaine undergoes extensive metabolism, primarily via CYP1A2-mediated aromatic hydroxylation to 3-OH-ropivacaine. The main metabolites excreted in the urine are the N-dealkylated metabolite (PPX) and 3-OH-ropivacaine. Other identified metabolites include 4-OH-ropivacaine, the 3-hydroxy-N-dealkylated (3-OH-PPX) and 4-hydroxy-N-dealkylated (4-OH-PPX) metabolites, and 2-hydroxy-methyl-ropivacaine (which has been identified but not quantified). Unbound PPX, 3-hydroxy-, and 4-hydroxy-ropivacaine have demonstrated pharmacological activity in animal models less than that of ropivacaine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following intravenous administration, 86% of the administered dose of ropivacaine is excreted in the urine, 1% of which comprises unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of ropivacaine is 1.8 ± 0.7 hours after intravascular administration and 4.2 ± 1 hour after epidural administration. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following intravenous administration, ropivacaine has a mean plasma clearance of 387 ± 107 mL/min, an unbound plasma clearance of 7.2 ± 1.6 L/min, and a renal clearance of 1 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): High systemic doses of ropivacaine can result in central nervous system (CNS) and cardiovascular effects, with the CNS effects usually occurring at lower blood plasma concentrations and additional cardiovascular effects occurring at higher concentrations (although cardiovascular collapse may occur at lower concentrations). CNS effects include CNS excitation involving nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, and seizures. CNS depressant effects may follow, associated with drowsiness, loss of consciousness, respiratory depression and apnea. Cardiovascular events may be caused by hypoxemia secondary to respiratory depression and include hypotension, bradycardia, arrhythmias, and/or cardiac arrest. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Naropin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-ropivacaine Ropivacaina Ropivacaine Ropivacainum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ropivacaine is an amide-type local anesthetic used for local or regional anesthesia during surgery and for short-term management of acute pain. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Rosiglitazone interact?

•Drug A: Abatacept •Drug B: Rosiglitazone •Severity: MODERATE •Description: The metabolism of Rosiglitazone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rosiglitazone is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): When rosiglitazone is used as monotherapy, it is associated with increases in total cholesterol, LDL, and HDL. It is also associated with decreases in free fatty acids. Increases in LDL occurred primarily during the first 1 to 2 months of therapy with AVANDIA and LDL levels remained elevated above baseline throughout the trials. In contrast, HDL continued to rise over time. As a result, the LDL/HDL ratio peaked after 2 months of therapy and then appeared to decrease over time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rosiglitazone acts as a highly selective and potent agonist at peroxisome proliferator activated receptors (PPAR) in target tissues for insulin action such as adipose tissue, skeletal muscle, and liver. Activation of PPAR-gamma receptors regulates the transcription of insulin-responsive genes involved in the control of glucose production, transport, and utilization. In this way, rosiglitazone enhances tissue sensitivity to insulin. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of rosiglitazone is 99%. Peak plasma concentrations are observed about 1 hour after dosing. Administration of rosiglitazone with food resulted in no change in overall exposure (AUC), but there was an approximately 28% decrease in C max and a delay in T max (1.75 hours). These changes are not likely to be clinically significant; therefore, rosiglitazone may be administered with or without food. Maximum plasma concentration (Cmax) and the area under the curve (AUC) of rosiglitazone increase in a dose-proportional manner over the therapeutic dose range. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 17.6 L [oral volume of distribution Vss/F] 13.5 L [population mean, pediatric patients] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99.8% bound to plasma proteins, primarily albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Rosiglitazone is extensively metabolized in the liver to inactive metabolites via N-demethylation, hydroxylation, and conjugation with sulfate and glucuronic acid. In vitro data have shown that Cytochrome (CYP) P450 isoenzyme 2C8 (CYP2C8) and to a minor extent CYP2C9 are involved in the hepatic metabolism of rosiglitazone. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral or intravenous administration of [14C]rosiglitazone maleate, approximately 64% and 23% of the dose was eliminated in the urine and in the feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-4 hours (single oral dose, independent of dose) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Oral clearance (CL) = 3.03 ± 0.87 L/hr [1 mg Fasting] Oral CL = 2.89 ± 0.71 L/hr [2 mg Fasting] Oral CL = 2.85 ± 0.69 L/hr [8 mg Fasting] Oral CL = 2.97 ± 0.81 L/hr [8 mg Fed] 3.15 L/hr [Population mean, Pediatric patients] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include fluid retention, congestive heart failure (CHF), liver disease •Brand Names (Drug A): Orencia •Brand Names (Drug B): Avandamet, Avandia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rosiglitazon Rosiglitazona Rosiglitazone Rosiglitazonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rosiglitazone is a thiazolidinedione indicated as an adjunct to diet and exercise to maintain glycemic control in type 2 diabetes.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rosiglitazone interact? Information: •Drug A: Abatacept •Drug B: Rosiglitazone •Severity: MODERATE •Description: The metabolism of Rosiglitazone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rosiglitazone is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): When rosiglitazone is used as monotherapy, it is associated with increases in total cholesterol, LDL, and HDL. It is also associated with decreases in free fatty acids. Increases in LDL occurred primarily during the first 1 to 2 months of therapy with AVANDIA and LDL levels remained elevated above baseline throughout the trials. In contrast, HDL continued to rise over time. As a result, the LDL/HDL ratio peaked after 2 months of therapy and then appeared to decrease over time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rosiglitazone acts as a highly selective and potent agonist at peroxisome proliferator activated receptors (PPAR) in target tissues for insulin action such as adipose tissue, skeletal muscle, and liver. Activation of PPAR-gamma receptors regulates the transcription of insulin-responsive genes involved in the control of glucose production, transport, and utilization. In this way, rosiglitazone enhances tissue sensitivity to insulin. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of rosiglitazone is 99%. Peak plasma concentrations are observed about 1 hour after dosing. Administration of rosiglitazone with food resulted in no change in overall exposure (AUC), but there was an approximately 28% decrease in C max and a delay in T max (1.75 hours). These changes are not likely to be clinically significant; therefore, rosiglitazone may be administered with or without food. Maximum plasma concentration (Cmax) and the area under the curve (AUC) of rosiglitazone increase in a dose-proportional manner over the therapeutic dose range. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 17.6 L [oral volume of distribution Vss/F] 13.5 L [population mean, pediatric patients] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99.8% bound to plasma proteins, primarily albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Rosiglitazone is extensively metabolized in the liver to inactive metabolites via N-demethylation, hydroxylation, and conjugation with sulfate and glucuronic acid. In vitro data have shown that Cytochrome (CYP) P450 isoenzyme 2C8 (CYP2C8) and to a minor extent CYP2C9 are involved in the hepatic metabolism of rosiglitazone. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral or intravenous administration of [14C]rosiglitazone maleate, approximately 64% and 23% of the dose was eliminated in the urine and in the feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-4 hours (single oral dose, independent of dose) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Oral clearance (CL) = 3.03 ± 0.87 L/hr [1 mg Fasting] Oral CL = 2.89 ± 0.71 L/hr [2 mg Fasting] Oral CL = 2.85 ± 0.69 L/hr [8 mg Fasting] Oral CL = 2.97 ± 0.81 L/hr [8 mg Fed] 3.15 L/hr [Population mean, Pediatric patients] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects include fluid retention, congestive heart failure (CHF), liver disease •Brand Names (Drug A): Orencia •Brand Names (Drug B): Avandamet, Avandia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rosiglitazon Rosiglitazona Rosiglitazone Rosiglitazonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rosiglitazone is a thiazolidinedione indicated as an adjunct to diet and exercise to maintain glycemic control in type 2 diabetes. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Rosuvastatin interact?

•Drug A: Abatacept •Drug B: Rosuvastatin •Severity: MODERATE •Description: The metabolism of Rosuvastatin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The FDA monograph states that rosuvastatin is indicated as an adjunct to diet in the treatment of triglyceridemia, Primary Dysbetalipoproteinemia (Type III Hyperlipoproteinemia), and Homozygous Familial Hypercholesterolemia. The Health Canada monograph for rosuvastatin further specifies that rosuvastatin is indicated for the reduction of elevated total cholesterol (Total-C), LDL-C, ApoB, the Total-C/HDL-C ratio and triglycerides (TG) and for increasing HDL-C in hyperlipidemic and dyslipidemic conditions when response to diet and exercise alone has been inadequate. It is also indicated for the prevention of major cardiovascular events (including risk of myocardial infarction, nonfatal stroke, and coronary artery revascularization) in adult patients without documented history of cardiovascular or cerebrovascular events, but with at least two conventional risk factors for cardiovascular disease. Prescribing of statin medications is considered standard practice following any cardiovascular events and for people with a moderate to high risk of development of CVD. Statin-indicated conditions include diabetes mellitus, clinical atherosclerosis (including myocardial infarction, acute coronary syndromes, stable angina, documented coronary artery disease, stroke, trans ischemic attack (TIA), documented carotid disease, peripheral artery disease, and claudication), abdominal aortic aneurysm, chronic kidney disease, and severely elevated LDL-C levels. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rosuvastatin is a synthetic, enantiomerically pure antilipemic agent. It is used to lower total cholesterol, low density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB), non-high density lipoprotein-cholesterol (non-HDL-C), and trigleride (TG) plasma concentrations while increasing HDL-C concentrations. High LDL-C, low HDL-C and high TG concentrations in the plasma are associated with increased risk of atherosclerosis and cardiovascular disease. The total cholesterol to HDL-C ratio is a strong predictor of coronary artery disease and high ratios are associated with higher risk of disease. Increased levels of HDL-C are associated with lower cardiovascular risk. By decreasing LDL-C and TG and increasing HDL-C, rosuvastatin reduces the risk of cardiovascular morbidity and mortality. Elevated cholesterol levels, and in particular, elevated low-density lipoprotein (LDL) levels, are an important risk factor for the development of CVD. Use of statins to target and reduce LDL levels has been shown in a number of landmark studies to significantly reduce the risk of development of CVD and all-cause mortality. Statins are considered a cost-effective treatment option for CVD due to their evidence of reducing all-cause mortality including fatal and non-fatal CVD as well as the need for surgical revascularization or angioplasty following a heart attack. Evidence has shown that even for low-risk individuals (with <10% risk of a major vascular event occurring within 5 years) statins cause a 20%-22% relative reduction in major cardiovascular events (heart attack, stroke, coronary revascularization, and coronary death) for every 1 mmol/L reduction in LDL without any significant side effects or risks. Skeletal Muscle Effects Cases of myopathy and rhabdomyolysis with acute renal failure secondary to myoglobinuria have been reported with HMG-CoA reductase inhibitors, including rosuvastatin. These risks can occur at any dose level, but are increased at the highest dose (40 mg). Rosuvastatin should be prescribed with caution in patients with predisposing factors for myopathy (e.g., age ≥ 65 years, inadequately treated hypothyroidism, renal impairment). The risk of myopathy during treatment with rosuvastatin may be increased with concurrent administration of some other lipid-lowering therapies (such as fenofibrate or niacin ), gemfibrozil, cyclosporine, atazanavir / ritonavir, lopinavir /ritonavir, or simeprevir. Cases of myopathy, including rhabdomyolysis, have been reported with HMG-CoA reductase inhibitors, including rosuvastatin, coadministered with colchicine, and caution should therefore be exercised when prescribing these two medications together. Real-world data from observational studies has suggested that 10-15% of people taking statins may experience muscle aches at some point during treatment. Liver Enzyme Abnormalities Increases in serum transaminases have been reported with HMG-CoA reductase inhibitors, including rosuvastatin. In most cases, the elevations were transient and resolved or improved on continued therapy or after a brief interruption in therapy. There were two cases of jaundice, for which a relationship to rosuvastatin therapy could not be determined, which resolved after discontinuation of therapy. There were no cases of liver failure or irreversible liver disease in these trials. Endocrine Effects Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including rosuvastatin calcium tablets. Based on clinical trial data with rosuvastatin, in some instances these increases may exceed the threshold for the diagnosis of diabetes mellitus. An in vitro study found that atorvastatin, pravastatin, rosuvastatin, and pitavastatin exhibited a dose-dependent cytotoxic effect on human pancreas islet β cells, with reductions in cell viability of 32, 41, 34 and 29%, respectively, versus control]. Moreover, insulin secretion rates were decreased by 34, 30, 27 and 19%, respectively, relative to control. HMG-CoA reductase inhibitors interfere with cholesterol synthesis and lower cholesterol levels and, as such, might theoretically blunt adrenal or gonadal steroid hormone production. Rosuvastatin demonstrated no effect upon nonstimulated cortisol levels and no effect on thyroid metabolism as assessed by TSH plasma concentration. In rosuvastatin treated patients, there was no impairment of adrenocortical reserve and no reduction in plasma cortisol concentrations. Clinical studies with other HMG-CoA reductase inhibitors have suggested that these agents do not reduce plasma testosterone concentration. The effects of HMG-CoA reductase inhibitors on male fertility have not been studied. The effects, if any, on the pituitarygonadal axis in premenopausal women are unknown. Cardiovascular Ubiquinone levels were not measured in rosuvastatin clinical trials, however significant decreases in circulating ubiquinone levels in patients treated with other statins have been observed. The clinical significance of a potential long-term statin-induced deficiency of ubiquinone has not been established. It has been reported that a decrease in myocardial ubiquinone levels could lead to impaired cardiac function in patients with borderline congestive heart failure. Lipoprotein A In some patients, the beneficial effect of lowered total cholesterol and LDL-C levels may be partly blunted by a concomitant increase in the Lipoprotein(a) [Lp(a)] concentrations. Present knowledge suggests the importance of high Lp(a) levels as an emerging risk factor for coronary heart disease. It is thus desirable to maintain and reinforce lifestyle changes in high-risk patients placed on rosuvastatin therapy. Further studies have demonstrated statins affect Lp(a) levels differently in patients with dyslipidemia depending on their apo(a) phenotype; statins increase Lp(a) levels exclusively in patients with the low molecular weight apo(a) phenotype. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rosuvastatin is a statin medication and a competitive inhibitor of the enzyme HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early rate-limiting step in cholesterol biosynthesis. Rosuvastatin acts primarily in the liver, where decreased hepatic cholesterol concentrations stimulate the upregulation of hepatic low density lipoprotein (LDL) receptors which increases hepatic uptake of LDL. Rosuvastatin also inhibits hepatic synthesis of very low density lipoprotein (VLDL). The overall effect is a decrease in plasma LDL and VLDL. In vitro and in vivo animal studies also demonstrate that rosuvastatin exerts vasculoprotective effects independent of its lipid-lowering properties, also known as the pleiotropic effects of statins. This includes improvement in endothelial function, enhanced stability of atherosclerotic plaques, reduced oxidative stress and inflammation, and inhibition of the thrombogenic response. Statins have also been found to bind allosterically to β2 integrin function-associated antigen-1 (LFA-1), which plays an important role in leukocyte trafficking and in T cell activation. Rosuvastatin exerts an anti-inflammatory effect on rat mesenteric microvascular endothelium by attenuating leukocyte rolling, adherence and transmigration. The drug also modulates nitric oxide synthase (NOS) expression and reduces ischemic-reperfusion injuries in rat hearts. Rosuvastatin increases the bioavailability of nitric oxide by upregulating NOS and by increasing the stability of NOS through post-transcriptional polyadenylation. It is unclear as to how rosuvastatin brings about these effects though they may be due to decreased concentrations of mevalonic acid. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In a study of healthy white male volunteers, the absolute oral bioavailability of rosuvastatin was found to be approximately 20% while absorption was estimated to be 50%, which is consistent with a substantial first-pass effect after oral dosing. Another study in healthy volunteers found that the peak plasma concentration (Cmax) of rosuvastatin was 6.06ng/mL and was reached at a median of 5 hours following oral dosing. Both Cmax and AUC increased in approximate proportion to dose. Neither food nor evening versus morning administration was shown to have an effect on the AUC of rosuvastatin. Many statins are known to interact with hepatic uptake transporters and thus reach high concentrations at their site of action in the liver. Breast Cancer Resistance Protein (BCRP) is a membrane-bound protein that plays an important role in the absorption of rosuvastatin, particularly as CYP3A4 has minimal involvement in its metabolism. Evidence from pharmacogenetic studies of c.421C>A single nucleotide polymorphisms (SNPs) in the gene for BCRP has demonstrated that individuals with the 421AA genotype have reduced functional activity and 2.4-fold higher AUC and Cmax values for rosuvastatin compared to study individuals with the control 421CC genotype. This has important implications for the variation in response to the drug in terms of efficacy and toxicity, particularly as the BCRP c.421C>A polymorphism occurs more frequently in Asian populations than in Caucasians. Other statin drugs impacted by this polymorphism include fluvastatin and atorvastatin. Genetic differences in the OATP1B1 (organic-anion-transporting polypeptide 1B1) hepatic transporter have also been shown to impact rosuvastatin pharmacokinetics. Evidence from pharmacogenetic studies of the c.521T>C SNP showed that rosuvastatin AUC was increased 1.62-fold for individuals homozygous for 521CC compared to homozygous 521TT individuals. Other statin drugs impacted by this polymorphism include simvastatin, pitavastatin, atorvastatin, and pravastatin. For patients known to have the above-mentioned c.421AA BCRP or c.521CC OATP1B1 genotypes, a maximum daily dose of 20mg of rosuvastatin is recommended to avoid adverse effects from the increased exposure to the drug, such as muscle pain and risk of rhabdomyolysis. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Rosuvastatin undergoes first-pass extraction in the liver, which is the primary site of cholesterol synthesis and LDL-C clearance. The mean volume of distribution at steady-state of rosuvastatin is approximately 134 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rosuvastatin is 88% bound to plasma proteins, mostly albumin. This binding is reversible and independent of plasma concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rosuvastatin is not extensively metabolized, as demonstrated by the small amount of radiolabeled dose that is recovered as a metabolite (~10%). Cytochrome P450 (CYP) 2C9 is primarily responsible for the formation of rosuvastatin's major metabolite, N-desmethylrosuvastatin, which has approximately 20-50% of the pharmacological activity of its parent compound in vitro. However, this metabolic pathway isn't deemed to be clinically significant as there were no observable effects found on rosuvastatin pharmacokinetics when rosuvastatin was coadministered with fluconazole, a potent CYP2C9 inhibitor. In vitro and in vivo data indicate that rosuvastatin has no clinically significant cytochrome P450 interactions (as substrate, inhibitor or inducer). Consequently, there is little potential for drug-drug interactions upon coadministration with agents that are metabolized by cytochrome P450. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rosuvastatin is not extensively metabolized; approximately 10% of a radiolabeled dose is recovered as metabolite. Following oral administration, rosuvastatin and its metabolites are primarily excreted in the feces (90%). After an intravenous dose, approximately 28% of total body clearance was via the renal route, and 72% by the hepatic route. A study in healthy adult male volunteers found that approximately 90% of the rosuvastatin dose was recovered in feces within 72 hours after dose, while the remaining 10% was recovered in urine. The drug was completely excreted from the body after 10 days of dosing. They also found that approximately 76.8% of the excreted dose was unchanged from the parent compound, with the remaining dose recovered as the metabolites n-desmethyl rosuvastatin and rosuvastatin-5S-lactone. Renal tubular secretion is responsible for >90% of total renal clearance, and is believed to be mediated primarily by the uptake transporter OAT3 (Organic anion transporter 1), while OAT1 had minimal involvement. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life (t½) of rosuvastatin is approximately 19 hours and does not increase with increasing doses. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Generally well-tolerated. Side effects may include myalgia, constipation, asthenia, abdominal pain, and nausea. Other possible side effects include myotoxicity (myopathy, myositis, rhabdomyolysis) and hepatotoxicity. To avoid toxicity in Asian patients, lower doses should be considered. Pharmacokinetic studies show an approximately two-fold increase in peak plasma concentration and AUC in Asian patients (Philippino, Chinese, Japanese, Korean, Vietnamese, or Asian-Indian descent) compared to Caucasian patients. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Crestor, Ezallor, Roszet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rosuvastatin Rosuvastatina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rosuvastatin is an HMG-CoA reductase inhibitor used to lower lipid levels and reduce the risk of cardiovascular disease including myocardial infarction and stroke.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rosuvastatin interact? Information: •Drug A: Abatacept •Drug B: Rosuvastatin •Severity: MODERATE •Description: The metabolism of Rosuvastatin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The FDA monograph states that rosuvastatin is indicated as an adjunct to diet in the treatment of triglyceridemia, Primary Dysbetalipoproteinemia (Type III Hyperlipoproteinemia), and Homozygous Familial Hypercholesterolemia. The Health Canada monograph for rosuvastatin further specifies that rosuvastatin is indicated for the reduction of elevated total cholesterol (Total-C), LDL-C, ApoB, the Total-C/HDL-C ratio and triglycerides (TG) and for increasing HDL-C in hyperlipidemic and dyslipidemic conditions when response to diet and exercise alone has been inadequate. It is also indicated for the prevention of major cardiovascular events (including risk of myocardial infarction, nonfatal stroke, and coronary artery revascularization) in adult patients without documented history of cardiovascular or cerebrovascular events, but with at least two conventional risk factors for cardiovascular disease. Prescribing of statin medications is considered standard practice following any cardiovascular events and for people with a moderate to high risk of development of CVD. Statin-indicated conditions include diabetes mellitus, clinical atherosclerosis (including myocardial infarction, acute coronary syndromes, stable angina, documented coronary artery disease, stroke, trans ischemic attack (TIA), documented carotid disease, peripheral artery disease, and claudication), abdominal aortic aneurysm, chronic kidney disease, and severely elevated LDL-C levels. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rosuvastatin is a synthetic, enantiomerically pure antilipemic agent. It is used to lower total cholesterol, low density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB), non-high density lipoprotein-cholesterol (non-HDL-C), and trigleride (TG) plasma concentrations while increasing HDL-C concentrations. High LDL-C, low HDL-C and high TG concentrations in the plasma are associated with increased risk of atherosclerosis and cardiovascular disease. The total cholesterol to HDL-C ratio is a strong predictor of coronary artery disease and high ratios are associated with higher risk of disease. Increased levels of HDL-C are associated with lower cardiovascular risk. By decreasing LDL-C and TG and increasing HDL-C, rosuvastatin reduces the risk of cardiovascular morbidity and mortality. Elevated cholesterol levels, and in particular, elevated low-density lipoprotein (LDL) levels, are an important risk factor for the development of CVD. Use of statins to target and reduce LDL levels has been shown in a number of landmark studies to significantly reduce the risk of development of CVD and all-cause mortality. Statins are considered a cost-effective treatment option for CVD due to their evidence of reducing all-cause mortality including fatal and non-fatal CVD as well as the need for surgical revascularization or angioplasty following a heart attack. Evidence has shown that even for low-risk individuals (with <10% risk of a major vascular event occurring within 5 years) statins cause a 20%-22% relative reduction in major cardiovascular events (heart attack, stroke, coronary revascularization, and coronary death) for every 1 mmol/L reduction in LDL without any significant side effects or risks. Skeletal Muscle Effects Cases of myopathy and rhabdomyolysis with acute renal failure secondary to myoglobinuria have been reported with HMG-CoA reductase inhibitors, including rosuvastatin. These risks can occur at any dose level, but are increased at the highest dose (40 mg). Rosuvastatin should be prescribed with caution in patients with predisposing factors for myopathy (e.g., age ≥ 65 years, inadequately treated hypothyroidism, renal impairment). The risk of myopathy during treatment with rosuvastatin may be increased with concurrent administration of some other lipid-lowering therapies (such as fenofibrate or niacin ), gemfibrozil, cyclosporine, atazanavir / ritonavir, lopinavir /ritonavir, or simeprevir. Cases of myopathy, including rhabdomyolysis, have been reported with HMG-CoA reductase inhibitors, including rosuvastatin, coadministered with colchicine, and caution should therefore be exercised when prescribing these two medications together. Real-world data from observational studies has suggested that 10-15% of people taking statins may experience muscle aches at some point during treatment. Liver Enzyme Abnormalities Increases in serum transaminases have been reported with HMG-CoA reductase inhibitors, including rosuvastatin. In most cases, the elevations were transient and resolved or improved on continued therapy or after a brief interruption in therapy. There were two cases of jaundice, for which a relationship to rosuvastatin therapy could not be determined, which resolved after discontinuation of therapy. There were no cases of liver failure or irreversible liver disease in these trials. Endocrine Effects Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including rosuvastatin calcium tablets. Based on clinical trial data with rosuvastatin, in some instances these increases may exceed the threshold for the diagnosis of diabetes mellitus. An in vitro study found that atorvastatin, pravastatin, rosuvastatin, and pitavastatin exhibited a dose-dependent cytotoxic effect on human pancreas islet β cells, with reductions in cell viability of 32, 41, 34 and 29%, respectively, versus control]. Moreover, insulin secretion rates were decreased by 34, 30, 27 and 19%, respectively, relative to control. HMG-CoA reductase inhibitors interfere with cholesterol synthesis and lower cholesterol levels and, as such, might theoretically blunt adrenal or gonadal steroid hormone production. Rosuvastatin demonstrated no effect upon nonstimulated cortisol levels and no effect on thyroid metabolism as assessed by TSH plasma concentration. In rosuvastatin treated patients, there was no impairment of adrenocortical reserve and no reduction in plasma cortisol concentrations. Clinical studies with other HMG-CoA reductase inhibitors have suggested that these agents do not reduce plasma testosterone concentration. The effects of HMG-CoA reductase inhibitors on male fertility have not been studied. The effects, if any, on the pituitarygonadal axis in premenopausal women are unknown. Cardiovascular Ubiquinone levels were not measured in rosuvastatin clinical trials, however significant decreases in circulating ubiquinone levels in patients treated with other statins have been observed. The clinical significance of a potential long-term statin-induced deficiency of ubiquinone has not been established. It has been reported that a decrease in myocardial ubiquinone levels could lead to impaired cardiac function in patients with borderline congestive heart failure. Lipoprotein A In some patients, the beneficial effect of lowered total cholesterol and LDL-C levels may be partly blunted by a concomitant increase in the Lipoprotein(a) [Lp(a)] concentrations. Present knowledge suggests the importance of high Lp(a) levels as an emerging risk factor for coronary heart disease. It is thus desirable to maintain and reinforce lifestyle changes in high-risk patients placed on rosuvastatin therapy. Further studies have demonstrated statins affect Lp(a) levels differently in patients with dyslipidemia depending on their apo(a) phenotype; statins increase Lp(a) levels exclusively in patients with the low molecular weight apo(a) phenotype. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rosuvastatin is a statin medication and a competitive inhibitor of the enzyme HMG-CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early rate-limiting step in cholesterol biosynthesis. Rosuvastatin acts primarily in the liver, where decreased hepatic cholesterol concentrations stimulate the upregulation of hepatic low density lipoprotein (LDL) receptors which increases hepatic uptake of LDL. Rosuvastatin also inhibits hepatic synthesis of very low density lipoprotein (VLDL). The overall effect is a decrease in plasma LDL and VLDL. In vitro and in vivo animal studies also demonstrate that rosuvastatin exerts vasculoprotective effects independent of its lipid-lowering properties, also known as the pleiotropic effects of statins. This includes improvement in endothelial function, enhanced stability of atherosclerotic plaques, reduced oxidative stress and inflammation, and inhibition of the thrombogenic response. Statins have also been found to bind allosterically to β2 integrin function-associated antigen-1 (LFA-1), which plays an important role in leukocyte trafficking and in T cell activation. Rosuvastatin exerts an anti-inflammatory effect on rat mesenteric microvascular endothelium by attenuating leukocyte rolling, adherence and transmigration. The drug also modulates nitric oxide synthase (NOS) expression and reduces ischemic-reperfusion injuries in rat hearts. Rosuvastatin increases the bioavailability of nitric oxide by upregulating NOS and by increasing the stability of NOS through post-transcriptional polyadenylation. It is unclear as to how rosuvastatin brings about these effects though they may be due to decreased concentrations of mevalonic acid. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In a study of healthy white male volunteers, the absolute oral bioavailability of rosuvastatin was found to be approximately 20% while absorption was estimated to be 50%, which is consistent with a substantial first-pass effect after oral dosing. Another study in healthy volunteers found that the peak plasma concentration (Cmax) of rosuvastatin was 6.06ng/mL and was reached at a median of 5 hours following oral dosing. Both Cmax and AUC increased in approximate proportion to dose. Neither food nor evening versus morning administration was shown to have an effect on the AUC of rosuvastatin. Many statins are known to interact with hepatic uptake transporters and thus reach high concentrations at their site of action in the liver. Breast Cancer Resistance Protein (BCRP) is a membrane-bound protein that plays an important role in the absorption of rosuvastatin, particularly as CYP3A4 has minimal involvement in its metabolism. Evidence from pharmacogenetic studies of c.421C>A single nucleotide polymorphisms (SNPs) in the gene for BCRP has demonstrated that individuals with the 421AA genotype have reduced functional activity and 2.4-fold higher AUC and Cmax values for rosuvastatin compared to study individuals with the control 421CC genotype. This has important implications for the variation in response to the drug in terms of efficacy and toxicity, particularly as the BCRP c.421C>A polymorphism occurs more frequently in Asian populations than in Caucasians. Other statin drugs impacted by this polymorphism include fluvastatin and atorvastatin. Genetic differences in the OATP1B1 (organic-anion-transporting polypeptide 1B1) hepatic transporter have also been shown to impact rosuvastatin pharmacokinetics. Evidence from pharmacogenetic studies of the c.521T>C SNP showed that rosuvastatin AUC was increased 1.62-fold for individuals homozygous for 521CC compared to homozygous 521TT individuals. Other statin drugs impacted by this polymorphism include simvastatin, pitavastatin, atorvastatin, and pravastatin. For patients known to have the above-mentioned c.421AA BCRP or c.521CC OATP1B1 genotypes, a maximum daily dose of 20mg of rosuvastatin is recommended to avoid adverse effects from the increased exposure to the drug, such as muscle pain and risk of rhabdomyolysis. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Rosuvastatin undergoes first-pass extraction in the liver, which is the primary site of cholesterol synthesis and LDL-C clearance. The mean volume of distribution at steady-state of rosuvastatin is approximately 134 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rosuvastatin is 88% bound to plasma proteins, mostly albumin. This binding is reversible and independent of plasma concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rosuvastatin is not extensively metabolized, as demonstrated by the small amount of radiolabeled dose that is recovered as a metabolite (~10%). Cytochrome P450 (CYP) 2C9 is primarily responsible for the formation of rosuvastatin's major metabolite, N-desmethylrosuvastatin, which has approximately 20-50% of the pharmacological activity of its parent compound in vitro. However, this metabolic pathway isn't deemed to be clinically significant as there were no observable effects found on rosuvastatin pharmacokinetics when rosuvastatin was coadministered with fluconazole, a potent CYP2C9 inhibitor. In vitro and in vivo data indicate that rosuvastatin has no clinically significant cytochrome P450 interactions (as substrate, inhibitor or inducer). Consequently, there is little potential for drug-drug interactions upon coadministration with agents that are metabolized by cytochrome P450. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Rosuvastatin is not extensively metabolized; approximately 10% of a radiolabeled dose is recovered as metabolite. Following oral administration, rosuvastatin and its metabolites are primarily excreted in the feces (90%). After an intravenous dose, approximately 28% of total body clearance was via the renal route, and 72% by the hepatic route. A study in healthy adult male volunteers found that approximately 90% of the rosuvastatin dose was recovered in feces within 72 hours after dose, while the remaining 10% was recovered in urine. The drug was completely excreted from the body after 10 days of dosing. They also found that approximately 76.8% of the excreted dose was unchanged from the parent compound, with the remaining dose recovered as the metabolites n-desmethyl rosuvastatin and rosuvastatin-5S-lactone. Renal tubular secretion is responsible for >90% of total renal clearance, and is believed to be mediated primarily by the uptake transporter OAT3 (Organic anion transporter 1), while OAT1 had minimal involvement. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life (t½) of rosuvastatin is approximately 19 hours and does not increase with increasing doses. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Generally well-tolerated. Side effects may include myalgia, constipation, asthenia, abdominal pain, and nausea. Other possible side effects include myotoxicity (myopathy, myositis, rhabdomyolysis) and hepatotoxicity. To avoid toxicity in Asian patients, lower doses should be considered. Pharmacokinetic studies show an approximately two-fold increase in peak plasma concentration and AUC in Asian patients (Philippino, Chinese, Japanese, Korean, Vietnamese, or Asian-Indian descent) compared to Caucasian patients. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Crestor, Ezallor, Roszet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rosuvastatin Rosuvastatina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rosuvastatin is an HMG-CoA reductase inhibitor used to lower lipid levels and reduce the risk of cardiovascular disease including myocardial infarction and stroke. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Rotavirus vaccine interact?

•Drug A: Abatacept •Drug B: Rotavirus vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Rotavirus vaccine can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Rotavirus vaccine interact? Information: •Drug A: Abatacept •Drug B: Rotavirus vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Rotavirus vaccine can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Rotigotine interact?

•Drug A: Abatacept •Drug B: Rotigotine •Severity: MODERATE •Description: The metabolism of Rotigotine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use/treatment in neurologic disorders and parkinson's disease as well as moderate-to-severe primary Restless Legs Syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rotigotine is an agonist at all 5 dopamine receptor subtypes (D1-D5) but binds to the D3 receptor with the highest affinity. It is also an antagonist at α-2-adrenergic receptors and an agonist at the 5HT1A receptors. Rotigotine also inhibits dopamine uptake and prolactin secretion. There is no indication of a QT/QTc prolonging effect of Neupro in doses up to 24 mg/24 hours. The effects of Neupro at doses up to 24 mg/24 hours (supratherapeutic doses) on the QT/QTc interval was evaluated in a double-blind, randomized, placebo- and positive-controlled (moxifloxacin 400 mg IV, single dose) parallel-group trial with an overall treatment period of 52 days in male and female patients with advanced-stage Parkinson's disease. Assay sensitivity was confirmed by significant QTc prolongation by moxifloxacin. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rotigotine, a member of the dopamine agonist class of drugs, is delivered continuously through the skin (transdermal) using a silicone-based patch that is replaced every 24 hours. A dopamine agonist works by activating dopamine receptors in the body, mimicking the effect of the neurotransmitter dopamine. The precise mechanism of action of rotigotine as a treatment for Restless Legs Syndrome is unknown but is thought to be related to its ability to stimulate dopamine •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability varies depending on the application site. Differences in bioavailability were very small between the abdomen and hip (<1%). In contrast, the shoulder and thigh had a very large different in measured bioavailability (46%), with the shoulder showing the higher value. Tmax, 8 mg dose = 15 - 18 hours (it take approximately 3 hours until rotigotine reaches detectable levels in the plasma). The peak concentration cannot be observered. Steady state is reached in 2-3 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The weight normalized apparent volume of distribution, (Vd/F), in humans is approximately 84 L/kg after repeated dose administration. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 92% in vitro and 89.5% in vivo. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic (CYP-mediated). Rotigotine is extensively and rapidly metabolized by conjugation and N-dealkylation. After intravenous dosing the predominant metabolites in human plasma are sulfate conjugates of rotigotine, glucuronide conjugates of rotigotine, sulfate conjugates of the N-despropyl-rotigotine and conjugates of N-desthienylethyl-rotigotine. Multiple CYP isoenzymes, sulfotransferases and two UDP-glucuronosyltransferases catalyze the metabolism of rotigotine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urine (71%), Fecal (23%). Most of rotigotine that is excreted in the urine is in the form of inactive conjugates. Unchanged drug made up less <1%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): After removal of the patch, plasma levels decreased with a terminal half-life of 5 to 7 hours. The pharmacokinetic profile showed a biphasic elimination with an initial half-life of 3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most likely symptoms of overdose would be those related to the pharmacodynamic profile of a dopamine agonist, including nausea, vomiting, hypotension, involuntary movements, hallucinations, confusion, convulsions, and other signs of excessive dopaminergic stimulation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Neupro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rotigotina Rotigotine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rotigotine is a non-selective dopamine agonist used for the treatment of Parkinson's Disease and Restless Leg Syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rotigotine interact? Information: •Drug A: Abatacept •Drug B: Rotigotine •Severity: MODERATE •Description: The metabolism of Rotigotine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use/treatment in neurologic disorders and parkinson's disease as well as moderate-to-severe primary Restless Legs Syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rotigotine is an agonist at all 5 dopamine receptor subtypes (D1-D5) but binds to the D3 receptor with the highest affinity. It is also an antagonist at α-2-adrenergic receptors and an agonist at the 5HT1A receptors. Rotigotine also inhibits dopamine uptake and prolactin secretion. There is no indication of a QT/QTc prolonging effect of Neupro in doses up to 24 mg/24 hours. The effects of Neupro at doses up to 24 mg/24 hours (supratherapeutic doses) on the QT/QTc interval was evaluated in a double-blind, randomized, placebo- and positive-controlled (moxifloxacin 400 mg IV, single dose) parallel-group trial with an overall treatment period of 52 days in male and female patients with advanced-stage Parkinson's disease. Assay sensitivity was confirmed by significant QTc prolongation by moxifloxacin. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rotigotine, a member of the dopamine agonist class of drugs, is delivered continuously through the skin (transdermal) using a silicone-based patch that is replaced every 24 hours. A dopamine agonist works by activating dopamine receptors in the body, mimicking the effect of the neurotransmitter dopamine. The precise mechanism of action of rotigotine as a treatment for Restless Legs Syndrome is unknown but is thought to be related to its ability to stimulate dopamine •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability varies depending on the application site. Differences in bioavailability were very small between the abdomen and hip (<1%). In contrast, the shoulder and thigh had a very large different in measured bioavailability (46%), with the shoulder showing the higher value. Tmax, 8 mg dose = 15 - 18 hours (it take approximately 3 hours until rotigotine reaches detectable levels in the plasma). The peak concentration cannot be observered. Steady state is reached in 2-3 days. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The weight normalized apparent volume of distribution, (Vd/F), in humans is approximately 84 L/kg after repeated dose administration. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 92% in vitro and 89.5% in vivo. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic (CYP-mediated). Rotigotine is extensively and rapidly metabolized by conjugation and N-dealkylation. After intravenous dosing the predominant metabolites in human plasma are sulfate conjugates of rotigotine, glucuronide conjugates of rotigotine, sulfate conjugates of the N-despropyl-rotigotine and conjugates of N-desthienylethyl-rotigotine. Multiple CYP isoenzymes, sulfotransferases and two UDP-glucuronosyltransferases catalyze the metabolism of rotigotine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urine (71%), Fecal (23%). Most of rotigotine that is excreted in the urine is in the form of inactive conjugates. Unchanged drug made up less <1%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): After removal of the patch, plasma levels decreased with a terminal half-life of 5 to 7 hours. The pharmacokinetic profile showed a biphasic elimination with an initial half-life of 3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most likely symptoms of overdose would be those related to the pharmacodynamic profile of a dopamine agonist, including nausea, vomiting, hypotension, involuntary movements, hallucinations, confusion, convulsions, and other signs of excessive dopaminergic stimulation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Neupro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rotigotina Rotigotine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rotigotine is a non-selective dopamine agonist used for the treatment of Parkinson's Disease and Restless Leg Syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Roxadustat interact?

•Drug A: Abatacept •Drug B: Roxadustat •Severity: MODERATE •Description: The metabolism of Roxadustat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Roxadustat is indicated for the treatment of adult patients with symptomatic anemia associated with chronic kidney disease (CKD). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Roxadustat dose-dependently improves iron bioavailability, increases hemoglobin production, and increases red blood cell mass in patients with anemia. In non-dialysis-dependent CKD patients with anemia, roxadustat maintained Hb for up to 2 years. It has a comparable efficacy to erythropoietin-stimulating agents in achieving Hb response. Roxadustat also reduces cholesterol levels from baseline, regardless of the use of statins or other lipid-lowering agents. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Anemia is a common complication of chronic kidney disease that may be caused by reduced production of renal erythropoietin (EPO), functional iron deficiency due to increased levels of hepcidin, blood loss, reduced erythrocyte survival duration, and inflammation. Hypoxia-inducible factor (HIF) is a transcription factor that induces several target oxygen-sensitive genes in response to low oxygen levels in the cellular environment, or hypoxia. Target genes are involved in erythropoiesis, such as those for EPO, EPO receptor, proteins promoting iron absorption, iron transport, and haem synthesis. Activation of the HIF pathway is an important adaptive responsive to hypoxia to increase red blood cell production. HIF is heterodimeric and contains an oxygen-regulated α-subunit. The α-subunit houses an oxygen-dependent degradation (ODD) domain that is regulated and hydroxylated by HIF-prolyl hydroxylase (HIF-PHD) enzymes under normoxic cellular conditions. HIF-PHD enzymes play a crucial role in maintaining a balance between oxygen availability and HIF activity. Roxadustat is a reversible and potent inhibitor of HIF-PHD enzymes: inhibition of HIF-PHD leads to the accumulation of functional HIF, an increase in plasma endogenous EPO production, enhanced erythropoiesis, and indirect suppression of hepcidin, which is an iron regulator protein that is increased during inflammation in chronic kidney disease. Roxadustat can also regulate iron transporter proteins and regulates iron metabolism by increasing serum transferrin, intestinal iron absorption and the release of stored iron in patients with anemia associated with dialysis-dependent or dialysis-independent CKD. Overall, roxadustat improves iron bioavailability, increases Hb production, and increases red cell mass. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Roxadustat plasma exposure (AUC and C max ) increases dose-proportionally within the recommended therapeutic dose range. In a three times per week dosing regimen, steady-state roxadustat plasma concentrations are achieved within one week (three doses) with minimal accumulation. Maximum plasma concentrations (C max ) are usually achieved at two hours post dose in the fasted state. Administration of roxadustat with food decreased C max by 25% but did not alter AUC as compared with the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The blood-to-plasma ratio of roxadustat is 0.6. The apparent volume of distribution at steady-state is 24 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Roxadustat is highly bound to human plasma proteins (approximately 99%), mainly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, roxadustat is a substrate for CYP2C8 and UGT1A9 enzymes. Roxadustat is primarily metabolized to hydroxy-roxadustat and roxadustat O-glucuronide. Unchanged roxadustat was the major circulating component in human plasma and detectable metabolites in human plasma constituted less than 10% of total drug-related material exposure. No human-specific metabolites were observed but roxadustat O-glucuronide was detected in human urine sample. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabelled roxadustat in healthy subjects, the mean recovery of radioactivity was 96% (50% in feces, 46% in urine). In feces, 28% of the dose was excreted as unchanged roxadustat. Less than 2% of the dose was recovered in urine as unchanged roxadustat. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean effective half-life of roxadustat is approximately 15 hours in patients with CKD. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent total body clearance (CL/F) of roxadustat is 1.1 L/h in patients with CKD not on dialysis and 1.4 L/h in patients with CKD on dialysis. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are limited information on the LD 50 values of roxadustat. Single doses of roxadustat 5 mg/kg (up to 510 mg) in healthy subjects led to a transient increase in heart rate, an increased frequency of mild to moderate musculoskeletal pain, headaches, sinus tachycardia, and less commonly, low blood pressure. All these effects were non-serious in nature. Roxadustat overdose can elevate hemoglobin levels above the desired level (10 - 12 g/dL), which should be managed with discontinuation of roxadustat treatment or reduction of drug dosage with careful monitoring and appropriate supportive treatment. Roxadustat and its metabolites are not significantly removed by hemodialysis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Roxadustat is a hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor used to treat symptomatic anemia associated with chronic kidney disease.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Roxadustat interact? Information: •Drug A: Abatacept •Drug B: Roxadustat •Severity: MODERATE •Description: The metabolism of Roxadustat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Roxadustat is indicated for the treatment of adult patients with symptomatic anemia associated with chronic kidney disease (CKD). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Roxadustat dose-dependently improves iron bioavailability, increases hemoglobin production, and increases red blood cell mass in patients with anemia. In non-dialysis-dependent CKD patients with anemia, roxadustat maintained Hb for up to 2 years. It has a comparable efficacy to erythropoietin-stimulating agents in achieving Hb response. Roxadustat also reduces cholesterol levels from baseline, regardless of the use of statins or other lipid-lowering agents. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Anemia is a common complication of chronic kidney disease that may be caused by reduced production of renal erythropoietin (EPO), functional iron deficiency due to increased levels of hepcidin, blood loss, reduced erythrocyte survival duration, and inflammation. Hypoxia-inducible factor (HIF) is a transcription factor that induces several target oxygen-sensitive genes in response to low oxygen levels in the cellular environment, or hypoxia. Target genes are involved in erythropoiesis, such as those for EPO, EPO receptor, proteins promoting iron absorption, iron transport, and haem synthesis. Activation of the HIF pathway is an important adaptive responsive to hypoxia to increase red blood cell production. HIF is heterodimeric and contains an oxygen-regulated α-subunit. The α-subunit houses an oxygen-dependent degradation (ODD) domain that is regulated and hydroxylated by HIF-prolyl hydroxylase (HIF-PHD) enzymes under normoxic cellular conditions. HIF-PHD enzymes play a crucial role in maintaining a balance between oxygen availability and HIF activity. Roxadustat is a reversible and potent inhibitor of HIF-PHD enzymes: inhibition of HIF-PHD leads to the accumulation of functional HIF, an increase in plasma endogenous EPO production, enhanced erythropoiesis, and indirect suppression of hepcidin, which is an iron regulator protein that is increased during inflammation in chronic kidney disease. Roxadustat can also regulate iron transporter proteins and regulates iron metabolism by increasing serum transferrin, intestinal iron absorption and the release of stored iron in patients with anemia associated with dialysis-dependent or dialysis-independent CKD. Overall, roxadustat improves iron bioavailability, increases Hb production, and increases red cell mass. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Roxadustat plasma exposure (AUC and C max ) increases dose-proportionally within the recommended therapeutic dose range. In a three times per week dosing regimen, steady-state roxadustat plasma concentrations are achieved within one week (three doses) with minimal accumulation. Maximum plasma concentrations (C max ) are usually achieved at two hours post dose in the fasted state. Administration of roxadustat with food decreased C max by 25% but did not alter AUC as compared with the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The blood-to-plasma ratio of roxadustat is 0.6. The apparent volume of distribution at steady-state is 24 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Roxadustat is highly bound to human plasma proteins (approximately 99%), mainly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, roxadustat is a substrate for CYP2C8 and UGT1A9 enzymes. Roxadustat is primarily metabolized to hydroxy-roxadustat and roxadustat O-glucuronide. Unchanged roxadustat was the major circulating component in human plasma and detectable metabolites in human plasma constituted less than 10% of total drug-related material exposure. No human-specific metabolites were observed but roxadustat O-glucuronide was detected in human urine sample. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabelled roxadustat in healthy subjects, the mean recovery of radioactivity was 96% (50% in feces, 46% in urine). In feces, 28% of the dose was excreted as unchanged roxadustat. Less than 2% of the dose was recovered in urine as unchanged roxadustat. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean effective half-life of roxadustat is approximately 15 hours in patients with CKD. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent total body clearance (CL/F) of roxadustat is 1.1 L/h in patients with CKD not on dialysis and 1.4 L/h in patients with CKD on dialysis. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are limited information on the LD 50 values of roxadustat. Single doses of roxadustat 5 mg/kg (up to 510 mg) in healthy subjects led to a transient increase in heart rate, an increased frequency of mild to moderate musculoskeletal pain, headaches, sinus tachycardia, and less commonly, low blood pressure. All these effects were non-serious in nature. Roxadustat overdose can elevate hemoglobin levels above the desired level (10 - 12 g/dL), which should be managed with discontinuation of roxadustat treatment or reduction of drug dosage with careful monitoring and appropriate supportive treatment. Roxadustat and its metabolites are not significantly removed by hemodialysis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Roxadustat is a hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor used to treat symptomatic anemia associated with chronic kidney disease. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Rozanolixizumab interact?

•Drug A: Abatacept •Drug B: Rozanolixizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Rozanolixizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rozanolixizumab-noli is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The pharmacological effect of rozanolixizumab-noli was assessed by measuring the decrease in serum IgG levels and AChR and MuSK autoantibody levels. In patients testing positive for AChR and MuSK autoantibodies who were treated with RYSTIGGO, there was a reduction in total IgG levels relative to baseline. Decreases in AChR autoantibody and MuSK autoantibody levels followed a similar pattern. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rozanolixizumab-noli is a humanized IgG4 monoclonal antibody that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rozanolixizumab-noli exhibited nonlinear pharmacokinetics. Rozanolixizumab-noli exposure increased in a greater than dose-proportional manner over a dose range from 1 mg/kg to 20 mg/kg (two times the maximum recommended dose) following subcutaneous administration. Following subcutaneous administration of rozanolixizumab-noli, peak plasma levels were achieved after approximately 2 days in healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of rozanolixizumab-noli is 6.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rozanolixizumab-noli is expected to be degraded by proteolytic enzymes into small peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent clearance for the rozanolixizumab-noli is 0.89 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are limited data on rozanolixizumab-noli use in pregnant women to inform a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Following the administration of rozanolixizumab-noli to pregnant monkeys at doses greater than those used clinically, increases in embryonic death, reduced body weight, and impaired immune function were observed in the absence of maternal toxicity. Subcutaneous administration of rozanolixizumab-noli (0 or 150 mg/kg) every 3 days for 26 weeks to sexually mature cynomolgus monkeys resulted in no adverse effects on sperm parameters (count, motility, or morphology) or estrus cyclicity. The dose tested in monkeys is 30 times the maximum recommended human dose of approximately 10 mg/kg, on a mg/kg/week basis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rystiggo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rozanolixizumab is a humanized monoclonal antibody targeting the human neonatal Fc receptor (FcRn) used to treat generalized myasthenia gravis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Rozanolixizumab interact? Information: •Drug A: Abatacept •Drug B: Rozanolixizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Rozanolixizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rozanolixizumab-noli is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The pharmacological effect of rozanolixizumab-noli was assessed by measuring the decrease in serum IgG levels and AChR and MuSK autoantibody levels. In patients testing positive for AChR and MuSK autoantibodies who were treated with RYSTIGGO, there was a reduction in total IgG levels relative to baseline. Decreases in AChR autoantibody and MuSK autoantibody levels followed a similar pattern. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rozanolixizumab-noli is a humanized IgG4 monoclonal antibody that binds to the neonatal Fc receptor (FcRn), resulting in the reduction of circulating IgG. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rozanolixizumab-noli exhibited nonlinear pharmacokinetics. Rozanolixizumab-noli exposure increased in a greater than dose-proportional manner over a dose range from 1 mg/kg to 20 mg/kg (two times the maximum recommended dose) following subcutaneous administration. Following subcutaneous administration of rozanolixizumab-noli, peak plasma levels were achieved after approximately 2 days in healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of rozanolixizumab-noli is 6.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rozanolixizumab-noli is expected to be degraded by proteolytic enzymes into small peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent clearance for the rozanolixizumab-noli is 0.89 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are limited data on rozanolixizumab-noli use in pregnant women to inform a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Following the administration of rozanolixizumab-noli to pregnant monkeys at doses greater than those used clinically, increases in embryonic death, reduced body weight, and impaired immune function were observed in the absence of maternal toxicity. Subcutaneous administration of rozanolixizumab-noli (0 or 150 mg/kg) every 3 days for 26 weeks to sexually mature cynomolgus monkeys resulted in no adverse effects on sperm parameters (count, motility, or morphology) or estrus cyclicity. The dose tested in monkeys is 30 times the maximum recommended human dose of approximately 10 mg/kg, on a mg/kg/week basis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rystiggo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rozanolixizumab is a humanized monoclonal antibody targeting the human neonatal Fc receptor (FcRn) used to treat generalized myasthenia gravis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Rubella virus vaccine interact?

•Drug A: Abatacept •Drug B: Rubella virus vaccine •Severity: MAJOR •Description: The risk or severity of infection can be increased when Rubella virus vaccine is combined with Abatacept. •Extended Description: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). The severity of the interaction is major.

Question: Does Abatacept and Rubella virus vaccine interact? Information: •Drug A: Abatacept •Drug B: Rubella virus vaccine •Severity: MAJOR •Description: The risk or severity of infection can be increased when Rubella virus vaccine is combined with Abatacept. •Extended Description: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). The severity of the interaction is major.

Does Abatacept and Rucaparib interact?

•Drug A: Abatacept •Drug B: Rucaparib •Severity: MODERATE •Description: The metabolism of Rucaparib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rucaparib is indicated for the maintenance treatment of adult patients with a deleterious BRCA mutation (germline and/or somatic)- associated recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum-based chemotherapy. Under accelerated approval by the FDA, rucaparib is also indicated for the treatment of adult patients with a deleterious BRCA mutation (germline and/or somatic)-associated metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane-based chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rucaparib is an anticancer agent that exerts cytotoxic effects against cancer cells. It works by inhibiting poly (ADP-ribose) polymerase (PARP), an enzyme that plays a role in DNA repair. Rucaparib inhibits PARP-1, PARP-2, and PARP-3. It also interacts with PARP-4, PARP-10, PARP-12, PARP-15, and PARP-16, but to a lesser extent. In mice, rucaparib accumulated and was retained in tumours, inhibiting PARP enzymes for seven days. Rucaparib decreases tumour growth in tumour cell lines with deficiencies in BRCA1/2 and other DNA repair genes. In addition to PARP inhibition, rucaparib demonstrated PARP-independent cytotoxic mechanisms in cancer cells. When co-administered with other chemotherapeutic agents, rucaparib contributed to synergistic or additive effects in vitro and in vivo. There is evidence that rucaparib can sensitize cancer cells to chemotherapy. Rucaparib can also cause vasodilation, which may increase tumour perfusion and enhance the accumulation of cytotoxic drugs in cancer cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): PARPs play a role in DNA repair by activating DNA damage response pathways, such as base excision repair, and facilitating DNA repair. PARPs were evaluated as novel anticancer therapeutic targets after discovering that PARP-1 inhibitors reduce tumour growth in BRCA-deficient cancers. BRCA1 and BRCA2 are tumour suppressor genes involved in various cellular processes related to cell growth and death, including DNA repair. More specifically, BRCA1 and BRCA2 are involved in homologous recombination (HR) DNA repair. Cancer cells with a deleterious BRCA mutation are HR-deficient, resulting in unregulated and aberrant cell repair and growth. Rucaparib inhibits PARP1, PARP2, and PARP3. Inhibiting PARP traps the enzyme on damaged DNA, halting the repair process and forming toxic PARP–DNA complexes. Alternatively, other DNA repair processes such as error-prone nonhomologous end joining (NHEJ) or alternative end-joining pathways can be initiated, leading to mutations or chromosomal change. Further DNA damage can trigger cancer cell apoptosis and cell death. Typically, inhibition of PARP converts single-strand breaks in DNA to double-strand breaks at replication forks. HR DNA repair pathways repair double-strand breaks; however, HR-deficient cancer cells lack this repair mechanism. Because HR-deficient cancer cells are more vulnerable to unsalvageable DNA damage, rucaparib-induced PARP inhibition leads to synthetic lethality. In this phenomenon, two non-lethal defects (HR deficiency and PARP inhibition) combine and cause cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rucaparib exhibits a linear pharmacokinetic profile over the dose range from 240 mg to 840 mg twice daily. The mean (coefficient of variation [CV]) steady-state rucaparib C max is 1940 ng/mL (54%) and AUC0-12h is 16900 h x ng/mL (54%) at the approved recommended dosage. The mean AUC accumulation ratio is 3.5 to 6.2 fold. The median T max at the steady state is 1.9 hours, with a range of 0 to 5.98 hours at the approved recommended dosage. The mean absolute bioavailability is 36%, with a range of 30 to 45%. A high-fat meal increased C max and AUC 0-24h by 20% and 38%, respectively. The T max was delayed by 2.5 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (coefficient of variation) apparent volume of distribution is 2300 L (21%). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rucaparib is 70% bound to human plasma proteins in vitro. Rucaparib preferentially distributed to red blood cells with a blood-to-plasma concentration ratio of 1.8. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, rucaparib is primarily metabolized by CYP2D6 and, to a lesser extent, by CYP1A2 and CYP3A4. In addition to CYP-based oxidation, rucaparib also undergoes N-demethylation, N-methylation, and glucuronidation. In one study, seven metabolites of rucaparib were identified in plasma, urine, and feces. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single oral dose of radiolabeled rucaparib, unchanged rucaparib accounted for 64% of the radioactivity. Rucaparib accounted for 45% and 95% of radioactivity in urine and feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (coefficient of variation) terminal elimination half-life is 26 (39%) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean (coefficient of variation) apparent total clearance at steady state is 44.2 L/h (45%). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information regarding the LD50 and overdose of rucaparib. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rubraca •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rucaparib is a poly (ADP-ribose) polymerase (PARP) inhibitor used to treat recurrent ovarian and prostate cancers in previously treated adults.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rucaparib interact? Information: •Drug A: Abatacept •Drug B: Rucaparib •Severity: MODERATE •Description: The metabolism of Rucaparib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Rucaparib is indicated for the maintenance treatment of adult patients with a deleterious BRCA mutation (germline and/or somatic)- associated recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum-based chemotherapy. Under accelerated approval by the FDA, rucaparib is also indicated for the treatment of adult patients with a deleterious BRCA mutation (germline and/or somatic)-associated metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane-based chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rucaparib is an anticancer agent that exerts cytotoxic effects against cancer cells. It works by inhibiting poly (ADP-ribose) polymerase (PARP), an enzyme that plays a role in DNA repair. Rucaparib inhibits PARP-1, PARP-2, and PARP-3. It also interacts with PARP-4, PARP-10, PARP-12, PARP-15, and PARP-16, but to a lesser extent. In mice, rucaparib accumulated and was retained in tumours, inhibiting PARP enzymes for seven days. Rucaparib decreases tumour growth in tumour cell lines with deficiencies in BRCA1/2 and other DNA repair genes. In addition to PARP inhibition, rucaparib demonstrated PARP-independent cytotoxic mechanisms in cancer cells. When co-administered with other chemotherapeutic agents, rucaparib contributed to synergistic or additive effects in vitro and in vivo. There is evidence that rucaparib can sensitize cancer cells to chemotherapy. Rucaparib can also cause vasodilation, which may increase tumour perfusion and enhance the accumulation of cytotoxic drugs in cancer cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): PARPs play a role in DNA repair by activating DNA damage response pathways, such as base excision repair, and facilitating DNA repair. PARPs were evaluated as novel anticancer therapeutic targets after discovering that PARP-1 inhibitors reduce tumour growth in BRCA-deficient cancers. BRCA1 and BRCA2 are tumour suppressor genes involved in various cellular processes related to cell growth and death, including DNA repair. More specifically, BRCA1 and BRCA2 are involved in homologous recombination (HR) DNA repair. Cancer cells with a deleterious BRCA mutation are HR-deficient, resulting in unregulated and aberrant cell repair and growth. Rucaparib inhibits PARP1, PARP2, and PARP3. Inhibiting PARP traps the enzyme on damaged DNA, halting the repair process and forming toxic PARP–DNA complexes. Alternatively, other DNA repair processes such as error-prone nonhomologous end joining (NHEJ) or alternative end-joining pathways can be initiated, leading to mutations or chromosomal change. Further DNA damage can trigger cancer cell apoptosis and cell death. Typically, inhibition of PARP converts single-strand breaks in DNA to double-strand breaks at replication forks. HR DNA repair pathways repair double-strand breaks; however, HR-deficient cancer cells lack this repair mechanism. Because HR-deficient cancer cells are more vulnerable to unsalvageable DNA damage, rucaparib-induced PARP inhibition leads to synthetic lethality. In this phenomenon, two non-lethal defects (HR deficiency and PARP inhibition) combine and cause cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rucaparib exhibits a linear pharmacokinetic profile over the dose range from 240 mg to 840 mg twice daily. The mean (coefficient of variation [CV]) steady-state rucaparib C max is 1940 ng/mL (54%) and AUC0-12h is 16900 h x ng/mL (54%) at the approved recommended dosage. The mean AUC accumulation ratio is 3.5 to 6.2 fold. The median T max at the steady state is 1.9 hours, with a range of 0 to 5.98 hours at the approved recommended dosage. The mean absolute bioavailability is 36%, with a range of 30 to 45%. A high-fat meal increased C max and AUC 0-24h by 20% and 38%, respectively. The T max was delayed by 2.5 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (coefficient of variation) apparent volume of distribution is 2300 L (21%). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rucaparib is 70% bound to human plasma proteins in vitro. Rucaparib preferentially distributed to red blood cells with a blood-to-plasma concentration ratio of 1.8. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, rucaparib is primarily metabolized by CYP2D6 and, to a lesser extent, by CYP1A2 and CYP3A4. In addition to CYP-based oxidation, rucaparib also undergoes N-demethylation, N-methylation, and glucuronidation. In one study, seven metabolites of rucaparib were identified in plasma, urine, and feces. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single oral dose of radiolabeled rucaparib, unchanged rucaparib accounted for 64% of the radioactivity. Rucaparib accounted for 45% and 95% of radioactivity in urine and feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean (coefficient of variation) terminal elimination half-life is 26 (39%) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean (coefficient of variation) apparent total clearance at steady state is 44.2 L/h (45%). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information regarding the LD50 and overdose of rucaparib. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rubraca •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rucaparib is a poly (ADP-ribose) polymerase (PARP) inhibitor used to treat recurrent ovarian and prostate cancers in previously treated adults. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Rupatadine interact?

•Drug A: Abatacept •Drug B: Rupatadine •Severity: MODERATE •Description: The metabolism of Rupatadine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the symptomatic relief of nasal and non-nasal symptoms of seasonal allergic rhinitis and perennial allergic rhinitis in patients 2 years of age and older. Also used for the symptomatic relief of chronic spontaneous urticaria in patients 2 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rupatadine is an anti allergenic and acts to reduce allergic symptoms like urticaria, rhinorrhea, sneezing and itching. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rupatadine is a dual histamine H1 receptor and platelet activating (PAF) receptor antagonist. During allergic response mast cells undergo degranulation, releasing histamine and other substances. Histamine acts on H1 receptors to produce symptoms of nasal blockage, rhinorhea, itching, and swelling. PAF is produced from phospholipids cleaved by phospholipase A2. It acts to produce vascular leakage which contributes to rhinorhea and nasal blockage. By blocking both the H1 receptor and PAF receptor, rupatidine prevents these mediators from exerting their effects and so reduces the severity of allergic symptoms. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rupatidine is rapidly absorbed with a Tmax of 1 h. Administration with a high fat meal increases exposure by 23% and increases Tmax to 2 h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution is 9799 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rupatidine is 98.5-99.0% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rupatadine is metabolized by oxidation mediated primarily by CYP3A4. CYP2C9, CYP2C19, and CYP2D6 are also involved to a lesser extent. The metabolites desloratidine and hydroxylated forms of desloratidine retain some activity as H1 receptor antagonists. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of elimination is 15.9 h in children 2-5 years old, 12.3 h in children 6-11 years old, 5.9 h in adults, and 8.7 h in geriatric patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance is 1556.2 L/h in young adults and 798.2 L/h in geriatric patients. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rupall •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rupatadine is a selective histamine H1 receptor antagonist and platelet activating factor (PAF) antagonist used to treat allergic rhinitis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Rupatadine interact? Information: •Drug A: Abatacept •Drug B: Rupatadine •Severity: MODERATE •Description: The metabolism of Rupatadine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the symptomatic relief of nasal and non-nasal symptoms of seasonal allergic rhinitis and perennial allergic rhinitis in patients 2 years of age and older. Also used for the symptomatic relief of chronic spontaneous urticaria in patients 2 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Rupatadine is an anti allergenic and acts to reduce allergic symptoms like urticaria, rhinorrhea, sneezing and itching. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Rupatadine is a dual histamine H1 receptor and platelet activating (PAF) receptor antagonist. During allergic response mast cells undergo degranulation, releasing histamine and other substances. Histamine acts on H1 receptors to produce symptoms of nasal blockage, rhinorhea, itching, and swelling. PAF is produced from phospholipids cleaved by phospholipase A2. It acts to produce vascular leakage which contributes to rhinorhea and nasal blockage. By blocking both the H1 receptor and PAF receptor, rupatidine prevents these mediators from exerting their effects and so reduces the severity of allergic symptoms. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rupatidine is rapidly absorbed with a Tmax of 1 h. Administration with a high fat meal increases exposure by 23% and increases Tmax to 2 h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution is 9799 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Rupatidine is 98.5-99.0% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Rupatadine is metabolized by oxidation mediated primarily by CYP3A4. CYP2C9, CYP2C19, and CYP2D6 are also involved to a lesser extent. The metabolites desloratidine and hydroxylated forms of desloratidine retain some activity as H1 receptor antagonists. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of elimination is 15.9 h in children 2-5 years old, 12.3 h in children 6-11 years old, 5.9 h in adults, and 8.7 h in geriatric patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance is 1556.2 L/h in young adults and 798.2 L/h in geriatric patients. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rupall •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Rupatadine is a selective histamine H1 receptor antagonist and platelet activating factor (PAF) antagonist used to treat allergic rhinitis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Ruxolitinib interact?

•Drug A: Abatacept •Drug B: Ruxolitinib •Severity: MAJOR •Description: The metabolism of Ruxolitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ruxolitinib is indicated for the treatment of the following conditions: intermediate or high-risk myelofibrosis (MF), including prima1y MF, post-polycythemia vera MF and post-essential thrombocythemia MF in adults. It is also used to treat disease-related splenomegaly or symptoms in adult patients with these conditions. polycythemia vera (PV) in adults who have had an inadequate response to or are intolerant of hydroxyurea. steroid-refracto1y acute graft-versus-host disease (GVHD) in adult and pediatric patients 12 years and older. chronic GVHD in patients aged 12 years and older who have failed one or two lines of systemic therapy. Topical ruxolitinib is indicated for: the short-term and non-continuous chronic treatment of mild to moderate atopic dermatitis in non-immunocompromised patients patients 12 years of age and older whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. the treatment of non-segmental vitiligo in adult and pediatric patients 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ruxolitinib is an antineoplastic agent that inhibits cell proliferation, induces apoptosis of malignant cells, and reduces pro-inflammatory cytokine plasma levels by inhibiting JAK-induced phosphorylation of signal transducer and activator of transcription (STAT). Inhibition of STAT3 phosphorylation, which is used as a marker of JAK activity, by ruxolitinib is achieved at two hours after dosing which returned to near baseline by 10 hours in patients with myelofibrosis and polycythemia vera. In clinical trials, ruxolitinib reduced splenomegaly and improved symptoms of myelofibrosis. In a mouse model of myeloproliferative neoplasms, administration of ruxolitinib was associated with prolonged survival. Ruxolitinib inhibits both mutant and wild-type JAK2; however, JAK2V617F mutation, which is often seen in approximately 50% of patients with myelofibrosis, was shown to reduce ruxolitinib sensitivity, which may also be associated with possible resistance to JAK inhibitor treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The Janus kinase (JAK) family of protein tyrosine kinases comprises JAK1, JAK2, JAK3, and non-receptor tyrosine kinase 2 (TYK2). JAKs play a pivotal role in intracellular signalling pathways of various cytokines and growth factors essential to hematopoiesis, such as interleukin, erythropoietin, and thrombopoietin. JAKs have diverse functions: JAK1 and JAK3 promote lymphocyte differentiation, survival, and function, while JAK2 promotes signal transduction of erythropoietin and thrombopoietin. JAKs are in close proximity to the cytokine and growth factor receptor’s cytoplasmic region. Upon binding of cytokines and growth factors, JAKs are activated, undergoing cross-phosphorylation and tyrosine phosphorylation. This process also reveals selective binding sites for STATs, which are DNA-binding proteins that also bind to the cytoplasmic region of cytokine or growth factor receptors. Activated JAKs and STATs translocate to the nucleus as transcription factors to regulate gene expression of pro-inflammatory cytokines such as IL-6, IL-10, and nuclear factor κB (NF-κB). They also activate downstream pathways that promote erythroid, myeloid, and megakaryocytic development. The molecular pathogenesis of myeloproliferative neoplasms is not fully understood; however, JAK2 is constitutively activated and the JAK-STAT signalling pathway becomes deregulated and aberrant. Ruxolitinib is a selective and potent inhibitor of JAK2 and JAK1, with some affinity against JAK3 and TYK2. Anticancer effects of ruxolitinib are attributed to its inhibition of JAKs and JAK-mediated phosphorylation of STAT3. By downregulating the JAK-STAT pathway, ruxolitinib inhibits myeloproliferation and suppresses the plasma levels of pro-inflammatory cytokines such as IL-6 and TNF-α. Activated JAKs are also implicated in graft-versus-host-disease (GVHD), which is a severe immune complication of allogeneic hematopoietic cell transplantation GVHD is associated with significant morbidity and mortality, especially for patients who do not respond well to corticosteroid therapy. Activated JAKS stimulate T-effector cell responses, leading to increased proliferation of effector T cells and heightened production of pro-inflammatory cytokines. By blocking JAK1 and JAk2, ruxolitinib inhibits donor T-cell expansion and suppresses pro-inflammatory responses. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, ruxolitinib undergoes rapid absorption and the peak concentrations are reached within one hour after administration. Over a single-dose range of 5 mg to 200 mg, the mean maximal plasma concentration (C max ) increases proportionally. C max ranged from 205 nM to 7100 nM and AUC ranged from 862 nM x hr to 30700 nM x hr. T max ranges from one to two hours following oral administration. Oral bioavailability is at least 95%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution (%coefficient of variation) at steady-state is 72 L (29%) in patients with myelofibrosis and 75 L (23%) in patients with polycythemia vera. It is not known whether ruxolitinib crosses the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ruxolitinib is approximately 97% bound to plasma proteins, mostly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): More than 99% of orally-administered ruxolitinib undergoes metabolism mediated by CYP3A4 and, to a lesser extent, CYP2C9. The major circulating metabolites in human plasma were M18 formed by 2-hydroxylation, and M16 and M27 (stereoisomers) formed by 3-hydroxylation. Other identified metabolites include M9 and M49, which are formed by hydroxylation and ketone formation. Not all metabolite structures are fully characterized and it is speculated that many metabolites exist in stereoisomers. Metabolites of ruxolitinib retain inhibitory activity against JAK1 and JAk2 to a lesser degree than the parent drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single radiolabeled dose of ruxolitinib, the drug was mainly eliminated through metabolism. About 74% of the total dose was excreted in urine and 22% was excreted in feces, mostly in the form of hydroxyl and oxo metabolites of ruxolitinib. The unchanged parent drug accounted for less than 1% of the excreted total radioactivity. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of ruxolitinib is approximately 3 hours and the mean half-life of its metabolites is approximately 5.8 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ruxolitinib clearance (% coefficient of variation) is 17.7 L/h in women and 22.1 L/h in men with myelofibrosis. Drug clearance was 12.7 L/h (42%) in patients with polycythemia vera and 11.9 L/h (43%) in patients with acute graft-versus-host disease. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 was 250 mg/kg. Single doses of ruxolitinib up to 200 mg were tolerated well. Higher doses than recommended repeat doses are associated with myelosuppression, including leukopenia, anemia, and thrombocytopenia. There is no known antidote for overdoses with ruxolitinib: it is recommended that patients are given appropriate supportive treatment. Hemodialysis is not expected to enhance the elimination of ruxolitinib. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jakafi, Jakavi, Opzelura •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ruxolitinib is a kinase inhibitor used to treat various types of myelofibrosis, polycythemia vera in patients who have not responded to or cannot tolerate hydroxyurea, and to treat graft-versus-host disease in cases that are refractory to steroid treatment.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Ruxolitinib interact? Information: •Drug A: Abatacept •Drug B: Ruxolitinib •Severity: MAJOR •Description: The metabolism of Ruxolitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ruxolitinib is indicated for the treatment of the following conditions: intermediate or high-risk myelofibrosis (MF), including prima1y MF, post-polycythemia vera MF and post-essential thrombocythemia MF in adults. It is also used to treat disease-related splenomegaly or symptoms in adult patients with these conditions. polycythemia vera (PV) in adults who have had an inadequate response to or are intolerant of hydroxyurea. steroid-refracto1y acute graft-versus-host disease (GVHD) in adult and pediatric patients 12 years and older. chronic GVHD in patients aged 12 years and older who have failed one or two lines of systemic therapy. Topical ruxolitinib is indicated for: the short-term and non-continuous chronic treatment of mild to moderate atopic dermatitis in non-immunocompromised patients patients 12 years of age and older whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. the treatment of non-segmental vitiligo in adult and pediatric patients 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ruxolitinib is an antineoplastic agent that inhibits cell proliferation, induces apoptosis of malignant cells, and reduces pro-inflammatory cytokine plasma levels by inhibiting JAK-induced phosphorylation of signal transducer and activator of transcription (STAT). Inhibition of STAT3 phosphorylation, which is used as a marker of JAK activity, by ruxolitinib is achieved at two hours after dosing which returned to near baseline by 10 hours in patients with myelofibrosis and polycythemia vera. In clinical trials, ruxolitinib reduced splenomegaly and improved symptoms of myelofibrosis. In a mouse model of myeloproliferative neoplasms, administration of ruxolitinib was associated with prolonged survival. Ruxolitinib inhibits both mutant and wild-type JAK2; however, JAK2V617F mutation, which is often seen in approximately 50% of patients with myelofibrosis, was shown to reduce ruxolitinib sensitivity, which may also be associated with possible resistance to JAK inhibitor treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The Janus kinase (JAK) family of protein tyrosine kinases comprises JAK1, JAK2, JAK3, and non-receptor tyrosine kinase 2 (TYK2). JAKs play a pivotal role in intracellular signalling pathways of various cytokines and growth factors essential to hematopoiesis, such as interleukin, erythropoietin, and thrombopoietin. JAKs have diverse functions: JAK1 and JAK3 promote lymphocyte differentiation, survival, and function, while JAK2 promotes signal transduction of erythropoietin and thrombopoietin. JAKs are in close proximity to the cytokine and growth factor receptor’s cytoplasmic region. Upon binding of cytokines and growth factors, JAKs are activated, undergoing cross-phosphorylation and tyrosine phosphorylation. This process also reveals selective binding sites for STATs, which are DNA-binding proteins that also bind to the cytoplasmic region of cytokine or growth factor receptors. Activated JAKs and STATs translocate to the nucleus as transcription factors to regulate gene expression of pro-inflammatory cytokines such as IL-6, IL-10, and nuclear factor κB (NF-κB). They also activate downstream pathways that promote erythroid, myeloid, and megakaryocytic development. The molecular pathogenesis of myeloproliferative neoplasms is not fully understood; however, JAK2 is constitutively activated and the JAK-STAT signalling pathway becomes deregulated and aberrant. Ruxolitinib is a selective and potent inhibitor of JAK2 and JAK1, with some affinity against JAK3 and TYK2. Anticancer effects of ruxolitinib are attributed to its inhibition of JAKs and JAK-mediated phosphorylation of STAT3. By downregulating the JAK-STAT pathway, ruxolitinib inhibits myeloproliferation and suppresses the plasma levels of pro-inflammatory cytokines such as IL-6 and TNF-α. Activated JAKs are also implicated in graft-versus-host-disease (GVHD), which is a severe immune complication of allogeneic hematopoietic cell transplantation GVHD is associated with significant morbidity and mortality, especially for patients who do not respond well to corticosteroid therapy. Activated JAKS stimulate T-effector cell responses, leading to increased proliferation of effector T cells and heightened production of pro-inflammatory cytokines. By blocking JAK1 and JAk2, ruxolitinib inhibits donor T-cell expansion and suppresses pro-inflammatory responses. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, ruxolitinib undergoes rapid absorption and the peak concentrations are reached within one hour after administration. Over a single-dose range of 5 mg to 200 mg, the mean maximal plasma concentration (C max ) increases proportionally. C max ranged from 205 nM to 7100 nM and AUC ranged from 862 nM x hr to 30700 nM x hr. T max ranges from one to two hours following oral administration. Oral bioavailability is at least 95%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution (%coefficient of variation) at steady-state is 72 L (29%) in patients with myelofibrosis and 75 L (23%) in patients with polycythemia vera. It is not known whether ruxolitinib crosses the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ruxolitinib is approximately 97% bound to plasma proteins, mostly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): More than 99% of orally-administered ruxolitinib undergoes metabolism mediated by CYP3A4 and, to a lesser extent, CYP2C9. The major circulating metabolites in human plasma were M18 formed by 2-hydroxylation, and M16 and M27 (stereoisomers) formed by 3-hydroxylation. Other identified metabolites include M9 and M49, which are formed by hydroxylation and ketone formation. Not all metabolite structures are fully characterized and it is speculated that many metabolites exist in stereoisomers. Metabolites of ruxolitinib retain inhibitory activity against JAK1 and JAk2 to a lesser degree than the parent drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single radiolabeled dose of ruxolitinib, the drug was mainly eliminated through metabolism. About 74% of the total dose was excreted in urine and 22% was excreted in feces, mostly in the form of hydroxyl and oxo metabolites of ruxolitinib. The unchanged parent drug accounted for less than 1% of the excreted total radioactivity. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of ruxolitinib is approximately 3 hours and the mean half-life of its metabolites is approximately 5.8 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Ruxolitinib clearance (% coefficient of variation) is 17.7 L/h in women and 22.1 L/h in men with myelofibrosis. Drug clearance was 12.7 L/h (42%) in patients with polycythemia vera and 11.9 L/h (43%) in patients with acute graft-versus-host disease. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 was 250 mg/kg. Single doses of ruxolitinib up to 200 mg were tolerated well. Higher doses than recommended repeat doses are associated with myelosuppression, including leukopenia, anemia, and thrombocytopenia. There is no known antidote for overdoses with ruxolitinib: it is recommended that patients are given appropriate supportive treatment. Hemodialysis is not expected to enhance the elimination of ruxolitinib. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jakafi, Jakavi, Opzelura •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ruxolitinib is a kinase inhibitor used to treat various types of myelofibrosis, polycythemia vera in patients who have not responded to or cannot tolerate hydroxyurea, and to treat graft-versus-host disease in cases that are refractory to steroid treatment. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Salicylic acid interact?

•Drug A: Abatacept •Drug B: Salicylic acid •Severity: MODERATE •Description: The metabolism of Salicylic acid can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Key additive in many skin-care products for the treatment of acne, psoriasis, callouses, corns, keratosis pilaris and warts. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Salicylic acid treats acne by causing skin cells to slough off more readily, preventing pores from clogging up. This effect on skin cells also makes salicylic acid an active ingredient in several shampoos meant to treat dandruff. Use of straight salicylic solution may cause hyperpigmentation on unpretreated skin for those with darker skin types (Fitzpatrick phototypes IV, V, VI), as well as with the lack of use of a broad spectrum sunblock. Subsalicylate in combination with bismuth form the popular stomach relief aid known commonly as Pepto-Bismol. When combined the two key ingredients help control diarrhea, nausea, heartburn, and even gas. It is also very mildly anti-biotic. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Salicylic acid directly irreversibly inhibits COX-1 and COX-2 to decrease conversion of arachidonic acid to precursors of prostaglandins and thromboxanes. Salicylate's use in rheumatic diseases is due to it's analgesic and anti-inflammatory activity. Salicylic acid is a key ingredient in many skin-care products for the treatment of acne, psoriasis, calluses, corns, keratosis pilaris, and warts. Salicylic acid allows cells of the epidermis to more readily slough off. Because of its effect on skin cells, salicylic acid is used in several shampoos used to treat dandruff. Salicylic acid is also used as an active ingredient in gels which remove verrucas (plantar warts). Salicylic acid competitively inhibits oxidation of uridine-5-diphosphoglucose (UDPG) with nicotinamide adenosine dinucleotide (NAD) and noncompetitively with UDPG. It also competitively inhibits the transferring of the glucuronyl group of uridine-5-phosphoglucuronic acid (UDPGA) to a phenolic acceptor. Inhibition of mucopoly saccharide synthesis is likely responsible for the slowing of wound healing with salicylates. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution is about 170 mL/kg of body weight. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Salicylic acid is about 90% plasma protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Salicylic acid is extensively metabolized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 10% is excreted unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral rat LD50: 891 mg/kg. Inhalation rat LC50: > 900 mg/m3/1hr. Irritation: skin rabbit: 500 mg/24H mild. Eye rabbit: 100 mg severe. Investigated a mutagen and reproductive effector. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Actikerall, Bensal, Bioelements Active Astringent, Cantharone Plus, Clearasil, Diprosalic, Keralyt, Salex, Saliject, Salinocaine, Salvax, Ultrasal, Virasal •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Salicylic acid is an acid used to treat acne, psoriasis, calluses, corns, keratosis pilaris, and warts.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Salicylic acid interact? Information: •Drug A: Abatacept •Drug B: Salicylic acid •Severity: MODERATE •Description: The metabolism of Salicylic acid can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Key additive in many skin-care products for the treatment of acne, psoriasis, callouses, corns, keratosis pilaris and warts. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Salicylic acid treats acne by causing skin cells to slough off more readily, preventing pores from clogging up. This effect on skin cells also makes salicylic acid an active ingredient in several shampoos meant to treat dandruff. Use of straight salicylic solution may cause hyperpigmentation on unpretreated skin for those with darker skin types (Fitzpatrick phototypes IV, V, VI), as well as with the lack of use of a broad spectrum sunblock. Subsalicylate in combination with bismuth form the popular stomach relief aid known commonly as Pepto-Bismol. When combined the two key ingredients help control diarrhea, nausea, heartburn, and even gas. It is also very mildly anti-biotic. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Salicylic acid directly irreversibly inhibits COX-1 and COX-2 to decrease conversion of arachidonic acid to precursors of prostaglandins and thromboxanes. Salicylate's use in rheumatic diseases is due to it's analgesic and anti-inflammatory activity. Salicylic acid is a key ingredient in many skin-care products for the treatment of acne, psoriasis, calluses, corns, keratosis pilaris, and warts. Salicylic acid allows cells of the epidermis to more readily slough off. Because of its effect on skin cells, salicylic acid is used in several shampoos used to treat dandruff. Salicylic acid is also used as an active ingredient in gels which remove verrucas (plantar warts). Salicylic acid competitively inhibits oxidation of uridine-5-diphosphoglucose (UDPG) with nicotinamide adenosine dinucleotide (NAD) and noncompetitively with UDPG. It also competitively inhibits the transferring of the glucuronyl group of uridine-5-phosphoglucuronic acid (UDPGA) to a phenolic acceptor. Inhibition of mucopoly saccharide synthesis is likely responsible for the slowing of wound healing with salicylates. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution is about 170 mL/kg of body weight. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Salicylic acid is about 90% plasma protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Salicylic acid is extensively metabolized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 10% is excreted unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral rat LD50: 891 mg/kg. Inhalation rat LC50: > 900 mg/m3/1hr. Irritation: skin rabbit: 500 mg/24H mild. Eye rabbit: 100 mg severe. Investigated a mutagen and reproductive effector. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Actikerall, Bensal, Bioelements Active Astringent, Cantharone Plus, Clearasil, Diprosalic, Keralyt, Salex, Saliject, Salinocaine, Salvax, Ultrasal, Virasal •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Salicylic acid is an acid used to treat acne, psoriasis, calluses, corns, keratosis pilaris, and warts. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Salmeterol interact?

•Drug A: Abatacept •Drug B: Salmeterol •Severity: MODERATE •Description: The metabolism of Salmeterol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Salmeterol is indicated in the treatment of asthma with an inhaled corticosteroid, prevention of exercise induced bronchospasm, and the maintenance of airflow obstruction and prevention of exacerbations of chronic obstructive pulmonary disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Salmeterol is a long acting beta-2 adrenergic receptor agonist that binds to both the active and exo sites of the beta-2 adrenergic receptor. Salmeterol has a longer duration of action than other beta-2 agonists like salbutamol. Patients should be counselled regarding the risks of long acting beta agonist (LABA) monotherapy, hypokalemia, hypoglycemia, and not to take this drug with another LABA. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Beta-2 adrenoceptor stimulation causes relaxation of bronchial smooth muscle, bronchodilation, and increased airflow. Salmeterol is hypothesized to bind to 2 sites on the beta-2 adrenoceptor. The saligenin moiety binds to the active site of the beta-2 adrenoceptor. The hydrophilic tail of salmeterol binds to leucine residues in the exo-site of the beta-2 adrenoceptor almost irreversibly, allowing salmeterol to persist in the active site, which is responsible for it's long duration of action. Another hypothesis is that the lipophilic drug diffuses into lipid bilayer of smooth muscle cells and provides a depot of drug to the cells over a longer period of time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In asthmatic patients, a 50µg dose of inhaled salmeterol powder reaches a C max of 47.897pg/mL, with a T max of 0.240h, and an AUC of 156.041pg/mL/h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In asthmatic patients, the volume of distribution of the central compartment is 177L and the volume of distribution of the peripheral compartment is 3160L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Salmeterol is 96% protein bound in plasma to albumin and alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Salmeterol is predominantly metabolized by CYP3A4 to alpha-hydroxysalmeterol, and minorly by an unknown mechanism to an O-dealkylated metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Salmeterol is 57.4% eliminated in the feces and 23% in the urine. Less than 5% of a dose is eliminated in the urine as unchanged salmeterol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of salmeterol is 5.5h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The average clearance of salmeterol in a group of asthmatic patients was 392L/h. Further data regarding the clearance of salmeterol is not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose have presented with metabolic acidosis, hyperlactatemia, anxiety, palpitations, chest pain, sinus tachycardia, ST depression, hypokalemia, hypophosphatemia. Though patients may also present with seizures, angina, hypertension or hypotension, arrhythmia, headache, tremor, muscle cramps, dry mouth, nausea, dizziness, fatigue, malaise, insomnia, and hyperglycemia. Patients should be given symptomatic and supportive treatment which may include intravenous fluids, potassium supplementation, a cardioselective beta-blocker, and cardiac monitoring. Data regarding the LD 50 of salmeterol is not readily available. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Advair, Airduo, Airduo Respiclick, Serevent, Serevent Diskus, Wixela •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Salmeterol is a long-acting beta-2 adrenergic receptor agonist used to treat asthma and COPD.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Salmeterol interact? Information: •Drug A: Abatacept •Drug B: Salmeterol •Severity: MODERATE •Description: The metabolism of Salmeterol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Salmeterol is indicated in the treatment of asthma with an inhaled corticosteroid, prevention of exercise induced bronchospasm, and the maintenance of airflow obstruction and prevention of exacerbations of chronic obstructive pulmonary disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Salmeterol is a long acting beta-2 adrenergic receptor agonist that binds to both the active and exo sites of the beta-2 adrenergic receptor. Salmeterol has a longer duration of action than other beta-2 agonists like salbutamol. Patients should be counselled regarding the risks of long acting beta agonist (LABA) monotherapy, hypokalemia, hypoglycemia, and not to take this drug with another LABA. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Beta-2 adrenoceptor stimulation causes relaxation of bronchial smooth muscle, bronchodilation, and increased airflow. Salmeterol is hypothesized to bind to 2 sites on the beta-2 adrenoceptor. The saligenin moiety binds to the active site of the beta-2 adrenoceptor. The hydrophilic tail of salmeterol binds to leucine residues in the exo-site of the beta-2 adrenoceptor almost irreversibly, allowing salmeterol to persist in the active site, which is responsible for it's long duration of action. Another hypothesis is that the lipophilic drug diffuses into lipid bilayer of smooth muscle cells and provides a depot of drug to the cells over a longer period of time. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In asthmatic patients, a 50µg dose of inhaled salmeterol powder reaches a C max of 47.897pg/mL, with a T max of 0.240h, and an AUC of 156.041pg/mL/h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In asthmatic patients, the volume of distribution of the central compartment is 177L and the volume of distribution of the peripheral compartment is 3160L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Salmeterol is 96% protein bound in plasma to albumin and alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Salmeterol is predominantly metabolized by CYP3A4 to alpha-hydroxysalmeterol, and minorly by an unknown mechanism to an O-dealkylated metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Salmeterol is 57.4% eliminated in the feces and 23% in the urine. Less than 5% of a dose is eliminated in the urine as unchanged salmeterol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of salmeterol is 5.5h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The average clearance of salmeterol in a group of asthmatic patients was 392L/h. Further data regarding the clearance of salmeterol is not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose have presented with metabolic acidosis, hyperlactatemia, anxiety, palpitations, chest pain, sinus tachycardia, ST depression, hypokalemia, hypophosphatemia. Though patients may also present with seizures, angina, hypertension or hypotension, arrhythmia, headache, tremor, muscle cramps, dry mouth, nausea, dizziness, fatigue, malaise, insomnia, and hyperglycemia. Patients should be given symptomatic and supportive treatment which may include intravenous fluids, potassium supplementation, a cardioselective beta-blocker, and cardiac monitoring. Data regarding the LD 50 of salmeterol is not readily available. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Advair, Airduo, Airduo Respiclick, Serevent, Serevent Diskus, Wixela •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Salmeterol is a long-acting beta-2 adrenergic receptor agonist used to treat asthma and COPD. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Saquinavir interact?

•Drug A: Abatacept •Drug B: Saquinavir •Severity: MODERATE •Description: The metabolism of Saquinavir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Saquinavir is indicated, in combination with ritonavir and other antiretroviral agents, for the treatment of HIV-1 infection in patients 16 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Saquinavir exerts its antiviral activity by inhibiting an enzyme critical for the HIV-1 viral lifecycle. Like other protease inhibitors, saquinavir has a propensity for participating in drug interactions - use caution when administering saquinavir to patients maintained on other pharmaceutical agents as pharmacodynamic and pharmacokinetic interactions are common. Saquinavir is known to increase the QTc-interval in otherwise healthy individuals, and should therefore be used with caution in patients maintained on other QTc-prolonging medications or for whom prolongation of the QTc-interval may be of particular consequence (e.g. patients with pre-existing heart disease). Careful and regular monitoring of patient bloodwork is recommended, as saquinavir has been associated with the development of metabolic complications (e.g. diabetes mellitus, hyperlipidemia) and worsening of pre-existing liver disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The HIV lifecycle is comprised of 3 distinct stages: assembly, involving creation and packaging of essential viral components; budding, wherein the viral particle crosses the host cell plasma membrane and forms a lipid envelope; and maturation, wherein the viral particle alters its structure and becomes infectious. At the center of this lifecycle is the Gag polyprotein which, along with the products of its proteolysis, coordinate these stages and function as the major structural proteins of the virus. The HIV-1 protease enzyme, a dimeric aspartic protease, is the enzyme responsible for cleaving the Gag polyprotein and thus plays a critical role in many aspects of the HIV viral lifecycle. Saquinavir is an inhibitor of the HIV-1 protease enzyme. Its design is based on the "peptidomimetic" principle, wherein the molecule contains a hydroxyethylene scaffold that mimics the normal peptide linkage (cleaved by HIV protease) but which itself cannot be cleaved. By preventing HIV-1 protease activity, and thus the proteolysis of the Gag polyprotein, saquinavir results in the production of immature, non-infectious viral particles. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of orally administered saquinavir is only ~4%, thought to be a consequence of incomplete absorption and extensive first-pass metabolism. It is co-administered with ritonavir, another protease inhibitor and a potent inhibitor of the enzymes responsible for saquinavir's first-pass metabolism, in order to dramatically boost its serum concentrations and, by extension, its therapeutic efficacy. Following administration of saquinavir 1000mg twice daily with ritonavir 100mg twice daily the AUC 24h at steady-state was 39026 ng.h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady-state volume of distribution of saquinavir is approximately 700 L, suggesting extensive distribution into tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Saquinavir is approximately 98% plasma protein-bound independent of serum concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Saquinavir is extensively metabolized in the liver following oral administration, and in vitro studies have shown that >90% of its biotransformation is mediated by the CYP3A4 isoenzyme. Saquinavir is rapidly metabolized to a number of inactive mono- and di-hydroxylated compounds. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The primary means of elimination of saquinavir appears to be extensive hepatic metabolism followed by fecal excretion of both the parent drug and metabolic products. Following the administration of radiolabeled saquinavir (both orally and intravenously), approximately 81-88% of radioactivity is recovered in the feces within 5 days of dosing while only 1-3% is recovered in the urine. Mass balance studies indicate that only 13% of orally-administered plasma radioactivity is attributed to unchanged parent drug, with the remainder comprising metabolic products of saquinavir's hepatic metabolism. In contrast, intravenous administration resulted in approximately 66% of the circulating plasma radioactivity being attributed to unchanged parent drug, suggesting a high degree of first-pass metabolism with oral administration. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The systemic clearance of saquinavir is approximately 1.14 L/h/kg following intravenous administration. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 of saquinavir in both rats and mice is >5 g/kg. Data regarding overdose with saquinavir are limited. No acute toxicities or sequelae were noted in a patient ingesting 8 grams of saquinavir as a single dose, and a second subject ingesting 2.4 grams as a single dose experienced throat pain that lasted for 6 hours and subsequently resolved. Treatment of overdose should consist of symptomatic and supportive measures. Dialysis is unlikely to be of benefit given saquinavir's extensive protein-binding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Invirase •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Saquinavir is an HIV protease inhibitor used in combination with other antiretroviral agents for the treatment of HIV-1 with advanced immunodeficiency.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Saquinavir interact? Information: •Drug A: Abatacept •Drug B: Saquinavir •Severity: MODERATE •Description: The metabolism of Saquinavir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Saquinavir is indicated, in combination with ritonavir and other antiretroviral agents, for the treatment of HIV-1 infection in patients 16 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Saquinavir exerts its antiviral activity by inhibiting an enzyme critical for the HIV-1 viral lifecycle. Like other protease inhibitors, saquinavir has a propensity for participating in drug interactions - use caution when administering saquinavir to patients maintained on other pharmaceutical agents as pharmacodynamic and pharmacokinetic interactions are common. Saquinavir is known to increase the QTc-interval in otherwise healthy individuals, and should therefore be used with caution in patients maintained on other QTc-prolonging medications or for whom prolongation of the QTc-interval may be of particular consequence (e.g. patients with pre-existing heart disease). Careful and regular monitoring of patient bloodwork is recommended, as saquinavir has been associated with the development of metabolic complications (e.g. diabetes mellitus, hyperlipidemia) and worsening of pre-existing liver disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The HIV lifecycle is comprised of 3 distinct stages: assembly, involving creation and packaging of essential viral components; budding, wherein the viral particle crosses the host cell plasma membrane and forms a lipid envelope; and maturation, wherein the viral particle alters its structure and becomes infectious. At the center of this lifecycle is the Gag polyprotein which, along with the products of its proteolysis, coordinate these stages and function as the major structural proteins of the virus. The HIV-1 protease enzyme, a dimeric aspartic protease, is the enzyme responsible for cleaving the Gag polyprotein and thus plays a critical role in many aspects of the HIV viral lifecycle. Saquinavir is an inhibitor of the HIV-1 protease enzyme. Its design is based on the "peptidomimetic" principle, wherein the molecule contains a hydroxyethylene scaffold that mimics the normal peptide linkage (cleaved by HIV protease) but which itself cannot be cleaved. By preventing HIV-1 protease activity, and thus the proteolysis of the Gag polyprotein, saquinavir results in the production of immature, non-infectious viral particles. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of orally administered saquinavir is only ~4%, thought to be a consequence of incomplete absorption and extensive first-pass metabolism. It is co-administered with ritonavir, another protease inhibitor and a potent inhibitor of the enzymes responsible for saquinavir's first-pass metabolism, in order to dramatically boost its serum concentrations and, by extension, its therapeutic efficacy. Following administration of saquinavir 1000mg twice daily with ritonavir 100mg twice daily the AUC 24h at steady-state was 39026 ng.h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady-state volume of distribution of saquinavir is approximately 700 L, suggesting extensive distribution into tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Saquinavir is approximately 98% plasma protein-bound independent of serum concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Saquinavir is extensively metabolized in the liver following oral administration, and in vitro studies have shown that >90% of its biotransformation is mediated by the CYP3A4 isoenzyme. Saquinavir is rapidly metabolized to a number of inactive mono- and di-hydroxylated compounds. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The primary means of elimination of saquinavir appears to be extensive hepatic metabolism followed by fecal excretion of both the parent drug and metabolic products. Following the administration of radiolabeled saquinavir (both orally and intravenously), approximately 81-88% of radioactivity is recovered in the feces within 5 days of dosing while only 1-3% is recovered in the urine. Mass balance studies indicate that only 13% of orally-administered plasma radioactivity is attributed to unchanged parent drug, with the remainder comprising metabolic products of saquinavir's hepatic metabolism. In contrast, intravenous administration resulted in approximately 66% of the circulating plasma radioactivity being attributed to unchanged parent drug, suggesting a high degree of first-pass metabolism with oral administration. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The systemic clearance of saquinavir is approximately 1.14 L/h/kg following intravenous administration. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 of saquinavir in both rats and mice is >5 g/kg. Data regarding overdose with saquinavir are limited. No acute toxicities or sequelae were noted in a patient ingesting 8 grams of saquinavir as a single dose, and a second subject ingesting 2.4 grams as a single dose experienced throat pain that lasted for 6 hours and subsequently resolved. Treatment of overdose should consist of symptomatic and supportive measures. Dialysis is unlikely to be of benefit given saquinavir's extensive protein-binding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Invirase •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Saquinavir is an HIV protease inhibitor used in combination with other antiretroviral agents for the treatment of HIV-1 with advanced immunodeficiency. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Sarilumab interact?

•Drug A: Abatacept •Drug B: Sarilumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Sarilumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sarilumab is indicated for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response or intolerance to one or more disease-modifying antirheumatic drugs (DMARDs); and adult patients with polymyalgia rheumatica (PMR) who have had an inadequate response to corticosteroids or who cannot tolerate corticosteroid taper. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Single-dose subcutaneous administration of sarilumab produced a rapid reduction of CRP levels, leading to normal levels after two weeks of treatment. Peak reduction in the absolute neutrophile count was observed after 3 to 4 days of treatment, followed by a recovery to baseline levels. A decrease in fibrinogen and serum amyloid A and an increase in hemoglobin and serum albumin were also detected. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sarilumab is a human recombinant IgG1 antibody that binds to both forms of interleukin 6 receptors (IL-6R), thus inhibiting IL-6-mediated signaling. IL-6 is a pleiotropic cytokine that activates immune cells (T and B cells) and hepatocytes for the release of acute phase proteins like CRP, serum amyloid A and fibrinogen, which are biomarkers of rheumatoid arthritis (RA) activity. IL-6 is also found in synovial fluid and plays a major role in the pathological inflammation and joint destruction features of RA. Thus, it is used for the treatment of RA due to its ability to inhibit intra-articular and systemic IL-6 signaling. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sarilumab is shown to be well absorbed in patients with rheumatoid arthritis after single subcutaneous administration, with a maximum serum concentration presented after 2 to 4 days. For the 150 mg every two weeks dose regimen, the AUC, C min and C max of sarilumab were 202 ± 120 mg.day/L, 6.35 ± 7.54 mg/L, and 20.0 ± 9.20 mg/L, respectively. For the 200 mg every two weeks dose regimen, the AUC, C min and C max of sarilumab were 395 ± 207 mg.day/L, 16.5 ± 14.1 mg/L, and 35.6 ± 15.2 mg/L, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In patients with rheumatoid arthritis, the apparent volume of distribution at steady state was 7.3 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sarilumab is a covalent heterotetramer composed of two disulfide-linked heavy chains covalently linked to a kappa light chain. The heavy chain has an IgG1 constant region with a single N-linked glycosylation site in the Fc portion of the molecule. The complementarity-determining regions (CDRs) within variable domains of both light and heavy chains combine to form the binding site for IL-6R. As an IgG1 molecule, sarilumab may mediate Fc-effector function upon binding to IL-6Ra, and it is prompt to bind to FcγRI, FcγRIIa, FCγRIIb, FcγRIIIa and FcγRIIIB. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of sarilumab has not been characterized. As a monoclonal antibody, it is thought to be degraded into small peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): At high concentrations, sarilumab is thought to be eliminated predominantly through a non-saturated proteolytic pathway, while at lower concentrations, the elimination will be done by saturable target-mediated elimination. As a monoclonal antibody, sarilumab is not eliminated through renal or hepatic pathways. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life will depend on the administered concentration. At 200 mg every 2 weeks, half-life is up to 10 days in patients with rheumatoid arthritis (RA) at steady state. At 150 mg every 2 weeks, half-life is up to 8 days in patients with RA at steady state. After the last steady state dose of 150 and 200 mg, the time to reach nondetectable concentration is 28 and 43 days, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Sarilumab is not eliminated via renal or hepatic pathways. Patients with rheumatoid arthritis have shown a trend toward higher clearance in the presence of anti-sarilumab antibodies. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Repeat dose exposure has been shown to produce a partially reversible decrease in neutrophil count and a reversible decrease in fibrinogen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kevzara •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sarilumab is a monoclonal antibody used to treat moderate to severe rheumatoid arthritis who have responded poorly or are intolerant of other DMARDs.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Sarilumab interact? Information: •Drug A: Abatacept •Drug B: Sarilumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Sarilumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sarilumab is indicated for the treatment of adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response or intolerance to one or more disease-modifying antirheumatic drugs (DMARDs); and adult patients with polymyalgia rheumatica (PMR) who have had an inadequate response to corticosteroids or who cannot tolerate corticosteroid taper. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Single-dose subcutaneous administration of sarilumab produced a rapid reduction of CRP levels, leading to normal levels after two weeks of treatment. Peak reduction in the absolute neutrophile count was observed after 3 to 4 days of treatment, followed by a recovery to baseline levels. A decrease in fibrinogen and serum amyloid A and an increase in hemoglobin and serum albumin were also detected. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sarilumab is a human recombinant IgG1 antibody that binds to both forms of interleukin 6 receptors (IL-6R), thus inhibiting IL-6-mediated signaling. IL-6 is a pleiotropic cytokine that activates immune cells (T and B cells) and hepatocytes for the release of acute phase proteins like CRP, serum amyloid A and fibrinogen, which are biomarkers of rheumatoid arthritis (RA) activity. IL-6 is also found in synovial fluid and plays a major role in the pathological inflammation and joint destruction features of RA. Thus, it is used for the treatment of RA due to its ability to inhibit intra-articular and systemic IL-6 signaling. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sarilumab is shown to be well absorbed in patients with rheumatoid arthritis after single subcutaneous administration, with a maximum serum concentration presented after 2 to 4 days. For the 150 mg every two weeks dose regimen, the AUC, C min and C max of sarilumab were 202 ± 120 mg.day/L, 6.35 ± 7.54 mg/L, and 20.0 ± 9.20 mg/L, respectively. For the 200 mg every two weeks dose regimen, the AUC, C min and C max of sarilumab were 395 ± 207 mg.day/L, 16.5 ± 14.1 mg/L, and 35.6 ± 15.2 mg/L, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In patients with rheumatoid arthritis, the apparent volume of distribution at steady state was 7.3 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sarilumab is a covalent heterotetramer composed of two disulfide-linked heavy chains covalently linked to a kappa light chain. The heavy chain has an IgG1 constant region with a single N-linked glycosylation site in the Fc portion of the molecule. The complementarity-determining regions (CDRs) within variable domains of both light and heavy chains combine to form the binding site for IL-6R. As an IgG1 molecule, sarilumab may mediate Fc-effector function upon binding to IL-6Ra, and it is prompt to bind to FcγRI, FcγRIIa, FCγRIIb, FcγRIIIa and FcγRIIIB. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of sarilumab has not been characterized. As a monoclonal antibody, it is thought to be degraded into small peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): At high concentrations, sarilumab is thought to be eliminated predominantly through a non-saturated proteolytic pathway, while at lower concentrations, the elimination will be done by saturable target-mediated elimination. As a monoclonal antibody, sarilumab is not eliminated through renal or hepatic pathways. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life will depend on the administered concentration. At 200 mg every 2 weeks, half-life is up to 10 days in patients with rheumatoid arthritis (RA) at steady state. At 150 mg every 2 weeks, half-life is up to 8 days in patients with RA at steady state. After the last steady state dose of 150 and 200 mg, the time to reach nondetectable concentration is 28 and 43 days, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Sarilumab is not eliminated via renal or hepatic pathways. Patients with rheumatoid arthritis have shown a trend toward higher clearance in the presence of anti-sarilumab antibodies. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Repeat dose exposure has been shown to produce a partially reversible decrease in neutrophil count and a reversible decrease in fibrinogen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kevzara •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sarilumab is a monoclonal antibody used to treat moderate to severe rheumatoid arthritis who have responded poorly or are intolerant of other DMARDs. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Satralizumab interact?

•Drug A: Abatacept •Drug B: Satralizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Satralizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Satralizumab is indicated for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. In Canada, it is also used in adolescent patients for the same indication. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Enspryng®, a satralizumab formulation developed by Chugai Pharmaceutical and Roche, utilizes a novel "recycling antibody technology" whereby the association of satralizumab to IL-6 receptors occurs in a pH-dependent manner. Satralizumab-bound IL-6 receptors are taken up into cells and transported into endosomes, a relatively acidic environment in comparison to plasma (pH 5.5-6.0 vs. pH 7.4) - this decrease in pH allows satralizumab to dissociate from the IL-6 receptor and be recycled back into the plasma, where it can bind to another IL-6 receptor and repeat the process. Satralizumab has been associated with an increased risk of infection, including serious and potentially fatal infections. It should not be administered to patients with active infections, including localized infections, until the infection resolves, and is contraindicated for use in patients with active hepatitis B or tuberculosis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin-6 (IL-6) is a pro-inflammatory cytokine which has been implicated in the pathogenesis of NMOSD. The inflammatory cascade triggered by IL-6 signaling is thought to result in the differentiation of T-cells into pro-inflammatory TH17 cells and the differentiation of B-cells into plasmablasts producing AQP4 autoantibodies. IL-6 may also play a role in increasing the permeability of the blood-brain barrier, thereby allowing penetration of autoantibodies and pro-inflammatory mediators into the central nervous system. Satralizumab is a humanized monoclonal antibody targeted against human IL-6 receptors. It binds to soluble and membrane-bound IL-6 receptors and prevents the signaling cascade, and subsequent pro-inflammatory effects, associated with its binding to endogenous IL-6. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC at steady-state, achieved after an 8-week loading period, were approximately 31.5 mcg/mL and 737 mcg.mL/day, respectively. Average C trough concentrations were approximately 19 mcg/mL. The bioavailability of satralizumab following subcutaneous injection has been reported to be between 78.5% and 85%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Satralizumab is subject to biphasic distribution - the estimated volume of distribution for the central and peripheral compartments are 3.46 L and 2.07 L, respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): While the metabolism of satralizumab has not been studied directly, monoclonal antibodies as a class are principally cleared by catabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monoclonal antibodies are typically eliminated via uptake into cells and subsequent catabolism via lysosomal degradation. Due to their large size, they are only eliminated renally under pathologic conditions. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of satralizumab is approximately 30 days (range 22-37 days). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total clearance of satralizumab is concentration-dependent and is estimated to be 0.0601-0.0679 L/day. The inter-compartmental clearance was 0.336 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no data regarding overdose of satralizumab. No serious adverse effects were noted in healthy adults receiving a single dose of 240mg subcutaneously in clinical trials. Patients experiencing a suspected overdose should be treated with symptomatic and supportive measures as clinically indicated. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enspryng •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sapelizumab Satralizumab satralizumab-mwge •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Satralizumab is a subcutaneously injected anti-IL-6 receptor monoclonal antibody for the treatment of neuromyelitis optica spectrum disorder (NMOSD).

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Satralizumab interact? Information: •Drug A: Abatacept •Drug B: Satralizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Satralizumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Satralizumab is indicated for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. In Canada, it is also used in adolescent patients for the same indication. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Enspryng®, a satralizumab formulation developed by Chugai Pharmaceutical and Roche, utilizes a novel "recycling antibody technology" whereby the association of satralizumab to IL-6 receptors occurs in a pH-dependent manner. Satralizumab-bound IL-6 receptors are taken up into cells and transported into endosomes, a relatively acidic environment in comparison to plasma (pH 5.5-6.0 vs. pH 7.4) - this decrease in pH allows satralizumab to dissociate from the IL-6 receptor and be recycled back into the plasma, where it can bind to another IL-6 receptor and repeat the process. Satralizumab has been associated with an increased risk of infection, including serious and potentially fatal infections. It should not be administered to patients with active infections, including localized infections, until the infection resolves, and is contraindicated for use in patients with active hepatitis B or tuberculosis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin-6 (IL-6) is a pro-inflammatory cytokine which has been implicated in the pathogenesis of NMOSD. The inflammatory cascade triggered by IL-6 signaling is thought to result in the differentiation of T-cells into pro-inflammatory TH17 cells and the differentiation of B-cells into plasmablasts producing AQP4 autoantibodies. IL-6 may also play a role in increasing the permeability of the blood-brain barrier, thereby allowing penetration of autoantibodies and pro-inflammatory mediators into the central nervous system. Satralizumab is a humanized monoclonal antibody targeted against human IL-6 receptors. It binds to soluble and membrane-bound IL-6 receptors and prevents the signaling cascade, and subsequent pro-inflammatory effects, associated with its binding to endogenous IL-6. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC at steady-state, achieved after an 8-week loading period, were approximately 31.5 mcg/mL and 737 mcg.mL/day, respectively. Average C trough concentrations were approximately 19 mcg/mL. The bioavailability of satralizumab following subcutaneous injection has been reported to be between 78.5% and 85%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Satralizumab is subject to biphasic distribution - the estimated volume of distribution for the central and peripheral compartments are 3.46 L and 2.07 L, respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): While the metabolism of satralizumab has not been studied directly, monoclonal antibodies as a class are principally cleared by catabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monoclonal antibodies are typically eliminated via uptake into cells and subsequent catabolism via lysosomal degradation. Due to their large size, they are only eliminated renally under pathologic conditions. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of satralizumab is approximately 30 days (range 22-37 days). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total clearance of satralizumab is concentration-dependent and is estimated to be 0.0601-0.0679 L/day. The inter-compartmental clearance was 0.336 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no data regarding overdose of satralizumab. No serious adverse effects were noted in healthy adults receiving a single dose of 240mg subcutaneously in clinical trials. Patients experiencing a suspected overdose should be treated with symptomatic and supportive measures as clinically indicated. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enspryng •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sapelizumab Satralizumab satralizumab-mwge •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Satralizumab is a subcutaneously injected anti-IL-6 receptor monoclonal antibody for the treatment of neuromyelitis optica spectrum disorder (NMOSD). Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Saxagliptin interact?

•Drug A: Abatacept •Drug B: Saxagliptin •Severity: MODERATE •Description: The metabolism of Saxagliptin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Treatment of type 2 diabetes mellitus to improve glycemic control in combination with other agents or as monotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Post-administration of saxagliptin, GLP-1 and GIP levels rise up to 2- to 3- fold. Because it is very selective of DPP-4 inhibition, there are fewer systemic side effects. Saxagliptin inhibits DPP-4 enzyme activity for a 24-hour period. It also decreased glucagon concentrations and increased glucose-dependent insulin secretion from pancreatic beta cells. The half maximal inhibitory concentration (IC50) is 0.5 nmol/L. Saxagliptin did not prolong the QTc interval to a clinically significant degree. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Saxagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor antidiabetic for the treatment of type 2 diabetes. DPP-4 inhibitors are a class of compounds that work by affecting the action of natural hormones in the body called incretins. Incretins decrease blood sugar by increasing consumption of sugar by the body, mainly through increasing insulin production in the pancreas, and by reducing production of sugar by the liver. [Bristol-Myers Squibb Press Release] DPP-4 is a membrane associated peptidase which is found in many tissues, lymphocytes and plasma. DPP-4 has two main mechanisms of action, an enzymatic function and another mechanism where DPP-4 binds adenosine deaminase, which conveys intracellular signals via dimerization when activated. Saxagliptin forms a reversible, histidine-assisted covalent bond between its nitrile group and the S630 hydroxyl oxygen on DPP-4. The inhibition of DPP-4 increases levels active of glucagon like peptide 1 (GLP-1), which inhibits glucagon production from pancreatic alpha cells and increases production of insulin from pancreatic beta cells. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a 5 mg single oral dose of saxagliptin to healthy subjects, the mean plasma AUC values for saxagliptin and its active metabolite were 78 ng•h/mL and 214 ng•h/mL, respectively. The corresponding plasma Cmax values were 24 ng/mL and 47 ng/mL, respectively. Saxagliptin did not accumulate following repeated doses. The median time to maximum concentration (Tmax) following the 5 mg once daily dose was 2 hours for saxagliptin and 4 hours for its active metabolite. Bioavailability, 2.5 - 50 mg dose = 67% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 151 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The in vitro protein binding of saxagliptin and its active metabolite in human serum is negligible (<10%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of saxagliptin is primarily mediated by cytochrome P450 3A4/5 (CYP3A4/5). 50% of the absorbed dose will undergo hepatic metabolism. The major metabolite of saxagliptin, 5-hydroxy saxagliptin, is also a DPP4 inhibitor, which is one-half as potent as saxagliptin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Saxagliptin is eliminated by both renal and hepatic pathways. Following a single 50 mg dose of 14C-saxagliptin, 24%, 36%, and 75% of the dose was excreted in the urine as saxagliptin, its active metabolite, and total radioactivity, respectively. A total of 22% of the administered radioactivity was recovered in feces representing the fraction of the saxagliptin dose excreted in bile and/or unabsorbed drug from the gastrointestinal tract. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Saxagliptin = 2.5 hours; 5-hydroxy saxagliptin = 3.1 hours; •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance, single 50 mg dose = 14 L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions reported in ≥5% of patients treated with saxagliptin and more commonly than in patients treated with placebo are: upper respiratory tract infection, urinary tract infection, and headache. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kombiglyze, Komboglyze, Onglyza, Qtern, Qternmet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Saxagliptin Saxagliptina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Saxagliptin is an DPP-4 inhibitor used for the management of type 2 diabetes mellitus.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Saxagliptin interact? Information: •Drug A: Abatacept •Drug B: Saxagliptin •Severity: MODERATE •Description: The metabolism of Saxagliptin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Treatment of type 2 diabetes mellitus to improve glycemic control in combination with other agents or as monotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Post-administration of saxagliptin, GLP-1 and GIP levels rise up to 2- to 3- fold. Because it is very selective of DPP-4 inhibition, there are fewer systemic side effects. Saxagliptin inhibits DPP-4 enzyme activity for a 24-hour period. It also decreased glucagon concentrations and increased glucose-dependent insulin secretion from pancreatic beta cells. The half maximal inhibitory concentration (IC50) is 0.5 nmol/L. Saxagliptin did not prolong the QTc interval to a clinically significant degree. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Saxagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor antidiabetic for the treatment of type 2 diabetes. DPP-4 inhibitors are a class of compounds that work by affecting the action of natural hormones in the body called incretins. Incretins decrease blood sugar by increasing consumption of sugar by the body, mainly through increasing insulin production in the pancreas, and by reducing production of sugar by the liver. [Bristol-Myers Squibb Press Release] DPP-4 is a membrane associated peptidase which is found in many tissues, lymphocytes and plasma. DPP-4 has two main mechanisms of action, an enzymatic function and another mechanism where DPP-4 binds adenosine deaminase, which conveys intracellular signals via dimerization when activated. Saxagliptin forms a reversible, histidine-assisted covalent bond between its nitrile group and the S630 hydroxyl oxygen on DPP-4. The inhibition of DPP-4 increases levels active of glucagon like peptide 1 (GLP-1), which inhibits glucagon production from pancreatic alpha cells and increases production of insulin from pancreatic beta cells. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a 5 mg single oral dose of saxagliptin to healthy subjects, the mean plasma AUC values for saxagliptin and its active metabolite were 78 ng•h/mL and 214 ng•h/mL, respectively. The corresponding plasma Cmax values were 24 ng/mL and 47 ng/mL, respectively. Saxagliptin did not accumulate following repeated doses. The median time to maximum concentration (Tmax) following the 5 mg once daily dose was 2 hours for saxagliptin and 4 hours for its active metabolite. Bioavailability, 2.5 - 50 mg dose = 67% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 151 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The in vitro protein binding of saxagliptin and its active metabolite in human serum is negligible (<10%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of saxagliptin is primarily mediated by cytochrome P450 3A4/5 (CYP3A4/5). 50% of the absorbed dose will undergo hepatic metabolism. The major metabolite of saxagliptin, 5-hydroxy saxagliptin, is also a DPP4 inhibitor, which is one-half as potent as saxagliptin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Saxagliptin is eliminated by both renal and hepatic pathways. Following a single 50 mg dose of 14C-saxagliptin, 24%, 36%, and 75% of the dose was excreted in the urine as saxagliptin, its active metabolite, and total radioactivity, respectively. A total of 22% of the administered radioactivity was recovered in feces representing the fraction of the saxagliptin dose excreted in bile and/or unabsorbed drug from the gastrointestinal tract. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Saxagliptin = 2.5 hours; 5-hydroxy saxagliptin = 3.1 hours; •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance, single 50 mg dose = 14 L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions reported in ≥5% of patients treated with saxagliptin and more commonly than in patients treated with placebo are: upper respiratory tract infection, urinary tract infection, and headache. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kombiglyze, Komboglyze, Onglyza, Qtern, Qternmet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Saxagliptin Saxagliptina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Saxagliptin is an DPP-4 inhibitor used for the management of type 2 diabetes mellitus. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Secukinumab interact?

•Drug A: Abatacept •Drug B: Secukinumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Secukinumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Secukinumab is indicated the treatment of moderate to severe plaque psoriasis in patients six years and older who are candidates for systemic therapy or phototherapy. In Europe, the drug is used in children and adolescents six to 18 years of age for this indication. It is also indicated for the treatment of active psoriatic arthritis (PsA). In the US, it is approved for patients two years of age and older while in Europe, it is used alone or in combination with methotrexate in patients six years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy. Secukinumab is also indicated in the treatment of active enthesitis-related arthritis (ERA). In the US, it is approved for patients four year of age and older. In Europe, it is used alone or in combination with methotrexate in patients six years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy. In the US, secukinumab is indicated for the treatment of adults with active ankylosing spondylitis, non-radiographic axial spondyloarthritis with objective signs of inflammation, moderate to severe hidradenitis suppurativa. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Secukinumab works to ameliorate inflammation in chronic inflammatory disorders by attenuating the release of proinflammatory cytokines and chemokines. Total serum IL-17A levels, representing free IL-17A and secukinumab-IL-17A complex, were increased to a plateau during drug treatment, then gradually decreased at the end of the treatment as the secukinumab-IL-17A complex was cleared from the body. In patients with plaque psoriasis, secukinumab reduced erythema, induration, and desquamation in plaque psoriasis lesions. Secukinumab also reduced acanthosis, parakeratosis, keratinocyte proliferation, and decrease in keratinocyte markers - all clinical manifestations of psoriasis. As the formation of CYP450 enzymes can be altered by increased levels of certain cytokines (e.g., IL-1, IL-6, IL-10, TNFα, IFN) during chronic inflammation, secukinumab can potentially alter the concentrations of CYP substrate drugs with a narrow therapeutic index. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin-17 (IL-17) is a family of proinflammatory cytokines that mediate normal inflammatory and immune responses. The production of IL-17 is mostly promoted by T cells, such as T-helper-17 (Th17) cells, but can also be caused by mast cells and neutrophils. IL-17 binds to IL-17 receptors, which are expressed on various cell types, including keratinocytes. IL-17 signalling pathway promotes angiogenesis and the release of proinflammatory cytokines, chemokines, and mediators of tissue damage. IL-17A is a member of IL-17 with the most prominent role in host defence and autoimmunity. IL-17A is often upregulated in several autoimmune disorders, such as psoriatic arthritis, rheumatoid arthritis, and ankylosing spondylitis, making it an important therapeutic target. IL-17A is also more potent than IL-17F, another member of IL-17, with a much greater affinity to the IL-17 receptor. Secukinumab selectively binds to and inhibits IL-17A, preventing its interaction with the IL-17 receptor and activation of the IL-17 receptor signalling pathway associated with inflammatory processes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a single subcutaneous dose of either 150 mg - which is one-half the recommended dose - in patients with plaque psoriasis, the mean C max and serum trough concentrations were 13.7 ± 4.8 mcg/mL and 22.8 ± 10.2 mcg/mL, respectively. Following administration of 300 mg, the mean C max and serum trough concentrations were 27.3 ± 9.5 mcg/mL and 45.4 ± 21.2 mcg/mL, respectively. Following subcutaneous injection, the C max is reached in five to six days. Steady-state concentrations were achieved by week 24 following the every 4-week dosing regimens. In healthy subjects and subjects with plaque psoriasis, bioavailability ranged from 55% to 77% following subcutaneous administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution during the terminal phase (V z ) ranged from 7.10 to 8.60 L in plaque psoriasis subjects who received secukinumab intravenously. These values suggest that secukinumab undergoes limited distribution to peripheral compartments. The volume of distribution increases with body weight. Following subcutaneous administration of a single 300 mg dose, drug concentrations in interstitial fluid in lesional and non-lesional skin of plaque psoriasis subjects ranged from 27% to 40% of those in serum at one and two weeks. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Secukinumab is expected to be degraded into small peptides and amino acids via catabolic pathways in the same manner as endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life ranged from 22 to 31 days in plaque psoriasis subjects following intravenous and subcutaneous administration across all psoriasis trials. The mean elimination half-life was 27 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean systemic clearance (CL) ranged from 0.14 L/day to 0.22 L/day. Clearance of secukinumab is dose- and time-independent, and is expected to increase with body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information available regarding the LD50 of secukinumab. In clinical trials, doses up to 30 mg/kg intravenously have been administered without dose-limiting toxicity. In the event of overdosage, it is recommended that the patient be monitored for any signs or symptoms of adverse reactions and appropriate symptomatic treatment be instituted immediately. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cosentyx •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Secukinumab is an immunomodulating agent and interleukin antagonist used to manage plaque psoriasis, psoriatic arthritis, ankylosing spondylitis, along with other joint inflammatory disorders.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Secukinumab interact? Information: •Drug A: Abatacept •Drug B: Secukinumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Secukinumab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Secukinumab is indicated the treatment of moderate to severe plaque psoriasis in patients six years and older who are candidates for systemic therapy or phototherapy. In Europe, the drug is used in children and adolescents six to 18 years of age for this indication. It is also indicated for the treatment of active psoriatic arthritis (PsA). In the US, it is approved for patients two years of age and older while in Europe, it is used alone or in combination with methotrexate in patients six years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy. Secukinumab is also indicated in the treatment of active enthesitis-related arthritis (ERA). In the US, it is approved for patients four year of age and older. In Europe, it is used alone or in combination with methotrexate in patients six years and older whose disease has responded inadequately to, or who cannot tolerate, conventional therapy. In the US, secukinumab is indicated for the treatment of adults with active ankylosing spondylitis, non-radiographic axial spondyloarthritis with objective signs of inflammation, moderate to severe hidradenitis suppurativa. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Secukinumab works to ameliorate inflammation in chronic inflammatory disorders by attenuating the release of proinflammatory cytokines and chemokines. Total serum IL-17A levels, representing free IL-17A and secukinumab-IL-17A complex, were increased to a plateau during drug treatment, then gradually decreased at the end of the treatment as the secukinumab-IL-17A complex was cleared from the body. In patients with plaque psoriasis, secukinumab reduced erythema, induration, and desquamation in plaque psoriasis lesions. Secukinumab also reduced acanthosis, parakeratosis, keratinocyte proliferation, and decrease in keratinocyte markers - all clinical manifestations of psoriasis. As the formation of CYP450 enzymes can be altered by increased levels of certain cytokines (e.g., IL-1, IL-6, IL-10, TNFα, IFN) during chronic inflammation, secukinumab can potentially alter the concentrations of CYP substrate drugs with a narrow therapeutic index. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Interleukin-17 (IL-17) is a family of proinflammatory cytokines that mediate normal inflammatory and immune responses. The production of IL-17 is mostly promoted by T cells, such as T-helper-17 (Th17) cells, but can also be caused by mast cells and neutrophils. IL-17 binds to IL-17 receptors, which are expressed on various cell types, including keratinocytes. IL-17 signalling pathway promotes angiogenesis and the release of proinflammatory cytokines, chemokines, and mediators of tissue damage. IL-17A is a member of IL-17 with the most prominent role in host defence and autoimmunity. IL-17A is often upregulated in several autoimmune disorders, such as psoriatic arthritis, rheumatoid arthritis, and ankylosing spondylitis, making it an important therapeutic target. IL-17A is also more potent than IL-17F, another member of IL-17, with a much greater affinity to the IL-17 receptor. Secukinumab selectively binds to and inhibits IL-17A, preventing its interaction with the IL-17 receptor and activation of the IL-17 receptor signalling pathway associated with inflammatory processes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a single subcutaneous dose of either 150 mg - which is one-half the recommended dose - in patients with plaque psoriasis, the mean C max and serum trough concentrations were 13.7 ± 4.8 mcg/mL and 22.8 ± 10.2 mcg/mL, respectively. Following administration of 300 mg, the mean C max and serum trough concentrations were 27.3 ± 9.5 mcg/mL and 45.4 ± 21.2 mcg/mL, respectively. Following subcutaneous injection, the C max is reached in five to six days. Steady-state concentrations were achieved by week 24 following the every 4-week dosing regimens. In healthy subjects and subjects with plaque psoriasis, bioavailability ranged from 55% to 77% following subcutaneous administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution during the terminal phase (V z ) ranged from 7.10 to 8.60 L in plaque psoriasis subjects who received secukinumab intravenously. These values suggest that secukinumab undergoes limited distribution to peripheral compartments. The volume of distribution increases with body weight. Following subcutaneous administration of a single 300 mg dose, drug concentrations in interstitial fluid in lesional and non-lesional skin of plaque psoriasis subjects ranged from 27% to 40% of those in serum at one and two weeks. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Secukinumab is expected to be degraded into small peptides and amino acids via catabolic pathways in the same manner as endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life ranged from 22 to 31 days in plaque psoriasis subjects following intravenous and subcutaneous administration across all psoriasis trials. The mean elimination half-life was 27 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean systemic clearance (CL) ranged from 0.14 L/day to 0.22 L/day. Clearance of secukinumab is dose- and time-independent, and is expected to increase with body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information available regarding the LD50 of secukinumab. In clinical trials, doses up to 30 mg/kg intravenously have been administered without dose-limiting toxicity. In the event of overdosage, it is recommended that the patient be monitored for any signs or symptoms of adverse reactions and appropriate symptomatic treatment be instituted immediately. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cosentyx •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Secukinumab is an immunomodulating agent and interleukin antagonist used to manage plaque psoriasis, psoriatic arthritis, ankylosing spondylitis, along with other joint inflammatory disorders. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Selegiline interact?

•Drug A: Abatacept •Drug B: Selegiline •Severity: MODERATE •Description: The metabolism of Selegiline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Monotherapy for initial treatment of Parkinson's disease, as well as an adjunct therapy in patients with a decreased response to levodopa/carbadopa. Also used for the palliative treatment of mild to moderate Alzheimer's disease and at higher doses, for the treatment of depression. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dopamine is an essential chemical that occurs in many parts of the body. It is the premature degradation of dopamine that results in the symptoms of Parkinson's disease. Monoamine oxidase (MAO) is an enzyme which accelerates the breakdown of dopamine. Selegiline can prolong the effects of dopamine in the brain by preventing its breakdown through seletively blocking MAO-B. It also may prevent the removal of dopamine between nerve endings and enhance release of dopamine from nerve cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the mechanisms for selegiline's beneficial action in the treatment of Parkinson's disease are not fully understood, the selective, irreversible inhibition of monoamine oxidase type B (MAO-B) is thought to be of primary importance. MAO-B is involved in the oxidative deamination of dopamine in the brain. Selegiline binds to MAO-B within the nigrostriatal pathways in the central nervous system, thus blocking microsomal metabolism of dopamine and enhancing the dopaminergic activity in the substantial nigra. Selegiline may also increase dopaminergic activity through mechanisms other than inhibition of MAO-B. At higher doses, selegiline can also inhibit monozmine oxidase type A (MAO-A), allowing it to be used for the treatment of depression. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed from the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): > 99.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1.2-2 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =63 mg/kg (rats, IV) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emsam, Zelapar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): L-Deprenalin Selegilina Selegiline Selegilinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selegiline is a monoamine oxidase inhibitor used to treat major depressive disorder and Parkinson's.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Selegiline interact? Information: •Drug A: Abatacept •Drug B: Selegiline •Severity: MODERATE •Description: The metabolism of Selegiline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Monotherapy for initial treatment of Parkinson's disease, as well as an adjunct therapy in patients with a decreased response to levodopa/carbadopa. Also used for the palliative treatment of mild to moderate Alzheimer's disease and at higher doses, for the treatment of depression. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dopamine is an essential chemical that occurs in many parts of the body. It is the premature degradation of dopamine that results in the symptoms of Parkinson's disease. Monoamine oxidase (MAO) is an enzyme which accelerates the breakdown of dopamine. Selegiline can prolong the effects of dopamine in the brain by preventing its breakdown through seletively blocking MAO-B. It also may prevent the removal of dopamine between nerve endings and enhance release of dopamine from nerve cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the mechanisms for selegiline's beneficial action in the treatment of Parkinson's disease are not fully understood, the selective, irreversible inhibition of monoamine oxidase type B (MAO-B) is thought to be of primary importance. MAO-B is involved in the oxidative deamination of dopamine in the brain. Selegiline binds to MAO-B within the nigrostriatal pathways in the central nervous system, thus blocking microsomal metabolism of dopamine and enhancing the dopaminergic activity in the substantial nigra. Selegiline may also increase dopaminergic activity through mechanisms other than inhibition of MAO-B. At higher doses, selegiline can also inhibit monozmine oxidase type A (MAO-A), allowing it to be used for the treatment of depression. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed from the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): > 99.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1.2-2 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =63 mg/kg (rats, IV) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emsam, Zelapar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): L-Deprenalin Selegilina Selegiline Selegilinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selegiline is a monoamine oxidase inhibitor used to treat major depressive disorder and Parkinson's. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Selexipag interact?

•Drug A: Abatacept •Drug B: Selexipag •Severity: MODERATE •Description: The metabolism of Selexipag can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Selexipag is indicated for the treatment of pulmonary arterial hypertension (PAH) to delay disease progression and reduce risk of hospitalization. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): At the maximum tolerated dose of 1600 mcg twice per day, selexipag was not found to prolong the QT interval to a clinically relevant extent. Both selexipag and its metabolite caused concentration-dependent inhibition of platelet aggregation in vitro with IC50 of 5.5 µM and 0.21 µM, respectively. However, at clinically relevant concentrations, there was no effect on platelet aggregation test parameters following multiple dose administration of selexipag in healthy patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Selexipag is a selective prostacyclin (IP, also called PGI2) receptor agonist. The key features of pulmonary arterial hypertension include a decrease in prostacyclin and prostacyclin synthase (enzyme that helps produce prostacyclin) in the lung. Prostacyclin is a potent vasodilator with anti-proliferative, anti-inflammatory, and anti-thrombotic effects; therefore, there is strong rationale for treatment with IP receptor agonists. Selexipag is chemically distinct as it is not PGI2 or a PGI2 analogue and has high selectivity for the IP receptor. It is metabolized by carboxylesterase 1 to yield an active metabolite (ACT-333679) that is approximately 37 times more potent than selexipag. Both selexipag and its metabolite are selective for the IP receptor over other prostanoid receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, maximum concentrations of selexipag and its metabolite were observed to be reached at 1-3 and 3-4 hours, respectively. Absorption was impaired in the presence of food, resulting in delayed time to maximum concentration as well as ~30% lower peak plasma concentration. However, exposure was not found to be significantly affected by food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both selexipag and its active metabolite are highly protein bound, approximately 99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Selexipag yields its active metabolite by hydrolysis of the acylsulfonamide by the enzyme hepatic carboxylesterase 1. Oxidative metabolism catalyzed by CYP3A4 and CYP2C8 results in hydroxylated and dealkylated products. UGT1A3 and UGT2B7 are involved in the glucuronidation of the active metabolite. Other than active metabolite, other metabolites in circulation do not exceed 3% of the total drug-related material. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 93% in feces, 12% in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Selexipag's terminal half life is 0.8-2.5 hours. The active metabolite's terminal half life is 6.2-13.5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): On average, 35 L/hour. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A 40-70% increase in exposure was observed in subjects with severe renal impairment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Uptravi, Uptravi Titration Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selexipag is a non prostanoid IP prostacyclin receptor agonist used to treat pulmonary arterial hypertension.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Selexipag interact? Information: •Drug A: Abatacept •Drug B: Selexipag •Severity: MODERATE •Description: The metabolism of Selexipag can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Selexipag is indicated for the treatment of pulmonary arterial hypertension (PAH) to delay disease progression and reduce risk of hospitalization. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): At the maximum tolerated dose of 1600 mcg twice per day, selexipag was not found to prolong the QT interval to a clinically relevant extent. Both selexipag and its metabolite caused concentration-dependent inhibition of platelet aggregation in vitro with IC50 of 5.5 µM and 0.21 µM, respectively. However, at clinically relevant concentrations, there was no effect on platelet aggregation test parameters following multiple dose administration of selexipag in healthy patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Selexipag is a selective prostacyclin (IP, also called PGI2) receptor agonist. The key features of pulmonary arterial hypertension include a decrease in prostacyclin and prostacyclin synthase (enzyme that helps produce prostacyclin) in the lung. Prostacyclin is a potent vasodilator with anti-proliferative, anti-inflammatory, and anti-thrombotic effects; therefore, there is strong rationale for treatment with IP receptor agonists. Selexipag is chemically distinct as it is not PGI2 or a PGI2 analogue and has high selectivity for the IP receptor. It is metabolized by carboxylesterase 1 to yield an active metabolite (ACT-333679) that is approximately 37 times more potent than selexipag. Both selexipag and its metabolite are selective for the IP receptor over other prostanoid receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, maximum concentrations of selexipag and its metabolite were observed to be reached at 1-3 and 3-4 hours, respectively. Absorption was impaired in the presence of food, resulting in delayed time to maximum concentration as well as ~30% lower peak plasma concentration. However, exposure was not found to be significantly affected by food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both selexipag and its active metabolite are highly protein bound, approximately 99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Selexipag yields its active metabolite by hydrolysis of the acylsulfonamide by the enzyme hepatic carboxylesterase 1. Oxidative metabolism catalyzed by CYP3A4 and CYP2C8 results in hydroxylated and dealkylated products. UGT1A3 and UGT2B7 are involved in the glucuronidation of the active metabolite. Other than active metabolite, other metabolites in circulation do not exceed 3% of the total drug-related material. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 93% in feces, 12% in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Selexipag's terminal half life is 0.8-2.5 hours. The active metabolite's terminal half life is 6.2-13.5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): On average, 35 L/hour. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A 40-70% increase in exposure was observed in subjects with severe renal impairment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Uptravi, Uptravi Titration Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selexipag is a non prostanoid IP prostacyclin receptor agonist used to treat pulmonary arterial hypertension. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Selumetinib interact?

•Drug A: Abatacept •Drug B: Selumetinib •Severity: MODERATE •Description: The metabolism of Selumetinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Selumetinib is indicated for the treatment of neurofibromatosis type 1 (NF1) in patients two years and older who have symptomatic, inoperable plexiform neurofibromas (PN). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Selumetinib is a non-ATP-competitive mitogen-activated protein kinase kinase 1 and 2 (MEK1 and MEK2) inhibitor. By selectively targeting MEK1 and MEK2, selumetinib is able to inhibit oncogenic downstream effects of the Raf-MEK-ERK signaling pathway, which is often overactive in certain types of cancer. Indeed, a study investigating the effects of selumetinib in children with NF-1 found that treatment with the anti-neoplastic resulted in reduced tumor size. Decreases in tumor-associated pain and improvements in overall function were also subjectively reported. Selumetinib has minimal off-target activity, contributing to its impressive safety profile. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The Ras-Raf-MEK-ERK signaling cascade is known to be activated in several types of cancer, and regulates the transcription of proteins involved in apoptosis. In addition, studies have shown that mutations of the Raf component of the pathway can contribute to chemotherapy drug resistance. Ras as well as several kinases and phosphatases are responsible for regulating the Raf-MEK-ERK pathway. Often in cancers, Ras (a G-protein coupled receptor) is deregulated, allowing downstream signalling to proceed unchecked. Through several complex steps, Raf phosphorylates and activates MEK, which then phosphorylates and activates ERK. ERK is then able to exert its effects on several downstream targets. As such, therapies inhibiting upstream components of this pathway have become attractive targets for cancer treatment. Selumetinib exerts its effects by selectively inhibiting MEK1 and MEK2 which can effectively blunt the pleiotropic effects of the Ras-Raf-MEK-ERK cascade. By inhibiting this oncogenic pathway, selumetinib reduces cell proliferation, and promotes pro-apoptotic signal transduction. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Based on several studies investigating selumetinib at various doses in both pediatric and adult populations, the Tmax generally ranges between 1- 1.5 hours. In healthy adults, the mean absolute oral bioavailability was reported to be 62%. Selumetinib should be administered on an empty stomach since food significantly decreases serum concentrations of the drug. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean apparent volume of distribution of selumetinib at steady state in pediatric patients ranged from 78 L to 171 L. A study in healthy adult males found a mean apparent volume of distribution of 146 L. Another study observing the pharmacokinetic effects of various selumetinib doses and regimens in select Japanese patients found that the apparent volume of distribution values at steady-state ranged from 73.2 - 148.1 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Separate studies investigating selumetinib protein binding found that 96% of selumetinib was bound to serum albumin, while <35% was bound to ɑ-1 acid glycoprotein. Overall, approximately 98.4% of selumetinib is plasma protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Selumetinib is heavily metabolized in the liver and the proposed metabolic pathway is as follows: Hydrolysis of selumetinib’s amide functional group produces M15 (AZ13326637), which contains a carboxylic acid. Elimination of the ethanediol moiety from the parent compound results in the formation of the primary amide M14 (AZ12791138) metabolite. Amide hydrolysis transforms M14 into M15, glucuronidation and further oxidation of M14 leads to M2, M6 and M1, and N-demethylation of M14 produces M12. The amide glucuronide (M2) is thought to be the major circulating metabolite. Demethylation of selumetinib produces the pharmacologically active M8 (AZ12442942), and further oxidation of M8 leads to M11. Glucuronidation of M8 produces M3 or M5, and elimination of the ethanediol moiety from M8 results in a primary amide, producing M12. Although the N-demethylated metabolite (M8) accounts for <10% of the circulating metabolites, it is responsible for approximately 21-35% of any observed pharmacological activity. Ribose conjugation transforms M12 into M9, while oxidation of M12 leads to M10 and M13 metabolites. Glucuronidation of M10 produces M1. Direct glucuronidation of selumetinib produces M4 or M7, which can both eventually transform into M3 and M5 metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 59% of selumetinib is eliminated in the feces, while 33% is eliminated in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Selumetinib is characterized by a short half-life. The elimination half-life associated with a dose of 25 mg/m in pediatric patients is 6.2 hours. In a study observing the pharmacokinetic effects of various selumetinib regimens in select Japanese patients, the half-life ranged from 9.2- 10.6 hours. In other studies where selumetinib 75 mg is administered twice daily, the half-life is reported to be approximately 13 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of selumetinib in pediatric patients is 8.8 L/hr. A study in healthy adult males found a clearance value of 15.7 L/hr. Another study observing the pharmacokinetic effects of various selumetinib doses and regimens in select Japanese patients found clearance values that ranged from 9.2 - 15.9 L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information regarding selumetinib is not readily available. Patients experiencing an overdose are at an increased risk of adverse effects such as cardiomyopathy, ocular toxicity, and diarrhea. It is generally thought that since selumetinib is extensively protein-bound, dialysis is unlikely to be helpful in situations of overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Koselugo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selumetinib is a MEK 1/2 inhibitor used in pediatric patients to treat neurofibromatosis type 1 (NF1) accompanied by symptomatic, inoperable plexiform neurofibromas (PN).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Selumetinib interact? Information: •Drug A: Abatacept •Drug B: Selumetinib •Severity: MODERATE •Description: The metabolism of Selumetinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Selumetinib is indicated for the treatment of neurofibromatosis type 1 (NF1) in patients two years and older who have symptomatic, inoperable plexiform neurofibromas (PN). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Selumetinib is a non-ATP-competitive mitogen-activated protein kinase kinase 1 and 2 (MEK1 and MEK2) inhibitor. By selectively targeting MEK1 and MEK2, selumetinib is able to inhibit oncogenic downstream effects of the Raf-MEK-ERK signaling pathway, which is often overactive in certain types of cancer. Indeed, a study investigating the effects of selumetinib in children with NF-1 found that treatment with the anti-neoplastic resulted in reduced tumor size. Decreases in tumor-associated pain and improvements in overall function were also subjectively reported. Selumetinib has minimal off-target activity, contributing to its impressive safety profile. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The Ras-Raf-MEK-ERK signaling cascade is known to be activated in several types of cancer, and regulates the transcription of proteins involved in apoptosis. In addition, studies have shown that mutations of the Raf component of the pathway can contribute to chemotherapy drug resistance. Ras as well as several kinases and phosphatases are responsible for regulating the Raf-MEK-ERK pathway. Often in cancers, Ras (a G-protein coupled receptor) is deregulated, allowing downstream signalling to proceed unchecked. Through several complex steps, Raf phosphorylates and activates MEK, which then phosphorylates and activates ERK. ERK is then able to exert its effects on several downstream targets. As such, therapies inhibiting upstream components of this pathway have become attractive targets for cancer treatment. Selumetinib exerts its effects by selectively inhibiting MEK1 and MEK2 which can effectively blunt the pleiotropic effects of the Ras-Raf-MEK-ERK cascade. By inhibiting this oncogenic pathway, selumetinib reduces cell proliferation, and promotes pro-apoptotic signal transduction. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Based on several studies investigating selumetinib at various doses in both pediatric and adult populations, the Tmax generally ranges between 1- 1.5 hours. In healthy adults, the mean absolute oral bioavailability was reported to be 62%. Selumetinib should be administered on an empty stomach since food significantly decreases serum concentrations of the drug. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean apparent volume of distribution of selumetinib at steady state in pediatric patients ranged from 78 L to 171 L. A study in healthy adult males found a mean apparent volume of distribution of 146 L. Another study observing the pharmacokinetic effects of various selumetinib doses and regimens in select Japanese patients found that the apparent volume of distribution values at steady-state ranged from 73.2 - 148.1 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Separate studies investigating selumetinib protein binding found that 96% of selumetinib was bound to serum albumin, while <35% was bound to ɑ-1 acid glycoprotein. Overall, approximately 98.4% of selumetinib is plasma protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Selumetinib is heavily metabolized in the liver and the proposed metabolic pathway is as follows: Hydrolysis of selumetinib’s amide functional group produces M15 (AZ13326637), which contains a carboxylic acid. Elimination of the ethanediol moiety from the parent compound results in the formation of the primary amide M14 (AZ12791138) metabolite. Amide hydrolysis transforms M14 into M15, glucuronidation and further oxidation of M14 leads to M2, M6 and M1, and N-demethylation of M14 produces M12. The amide glucuronide (M2) is thought to be the major circulating metabolite. Demethylation of selumetinib produces the pharmacologically active M8 (AZ12442942), and further oxidation of M8 leads to M11. Glucuronidation of M8 produces M3 or M5, and elimination of the ethanediol moiety from M8 results in a primary amide, producing M12. Although the N-demethylated metabolite (M8) accounts for <10% of the circulating metabolites, it is responsible for approximately 21-35% of any observed pharmacological activity. Ribose conjugation transforms M12 into M9, while oxidation of M12 leads to M10 and M13 metabolites. Glucuronidation of M10 produces M1. Direct glucuronidation of selumetinib produces M4 or M7, which can both eventually transform into M3 and M5 metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 59% of selumetinib is eliminated in the feces, while 33% is eliminated in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Selumetinib is characterized by a short half-life. The elimination half-life associated with a dose of 25 mg/m in pediatric patients is 6.2 hours. In a study observing the pharmacokinetic effects of various selumetinib regimens in select Japanese patients, the half-life ranged from 9.2- 10.6 hours. In other studies where selumetinib 75 mg is administered twice daily, the half-life is reported to be approximately 13 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of selumetinib in pediatric patients is 8.8 L/hr. A study in healthy adult males found a clearance value of 15.7 L/hr. Another study observing the pharmacokinetic effects of various selumetinib doses and regimens in select Japanese patients found clearance values that ranged from 9.2 - 15.9 L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information regarding selumetinib is not readily available. Patients experiencing an overdose are at an increased risk of adverse effects such as cardiomyopathy, ocular toxicity, and diarrhea. It is generally thought that since selumetinib is extensively protein-bound, dialysis is unlikely to be helpful in situations of overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Koselugo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Selumetinib is a MEK 1/2 inhibitor used in pediatric patients to treat neurofibromatosis type 1 (NF1) accompanied by symptomatic, inoperable plexiform neurofibromas (PN). Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Sertindole interact?

•Drug A: Abatacept •Drug B: Sertindole •Severity: MODERATE •Description: The metabolism of Sertindole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used in the treatment of schizophrenia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sertindole is an atypical antipsychotic at least as effective as haloperidol and risperidone in the treatment of neuroleptic-responsive schizophrenia. Sertindole improves negative symptoms, and is also effective for the treatment of neuroleptic-resistant schizophrenia. Sertindole is generally well tolerated and is associated with a low rate of extrapyramidal symptoms (EPS). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sertindole is an antipsychotic drug with affinity for dopamine D2, serotonin 5-HT2A and 5-HT2C, and alpha1-adrenoreceptors. Preclinical studies suggest that sertindole acts preferentially on limbic and cortical dopaminergic neurons and clinical trials have confirmed that sertindole is effective at a low dopamine D2 occupancy level. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Orally available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Sertindole is metabolized by cytochrome P450 isoenzymes CYP 2D6 and CYP 3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sertindol Sertindole Sertindolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sertindole is an atypical antipsychotic indicated in the treatment of schizophrenia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sertindole interact? Information: •Drug A: Abatacept •Drug B: Sertindole •Severity: MODERATE •Description: The metabolism of Sertindole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used in the treatment of schizophrenia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sertindole is an atypical antipsychotic at least as effective as haloperidol and risperidone in the treatment of neuroleptic-responsive schizophrenia. Sertindole improves negative symptoms, and is also effective for the treatment of neuroleptic-resistant schizophrenia. Sertindole is generally well tolerated and is associated with a low rate of extrapyramidal symptoms (EPS). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sertindole is an antipsychotic drug with affinity for dopamine D2, serotonin 5-HT2A and 5-HT2C, and alpha1-adrenoreceptors. Preclinical studies suggest that sertindole acts preferentially on limbic and cortical dopaminergic neurons and clinical trials have confirmed that sertindole is effective at a low dopamine D2 occupancy level. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Orally available. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Sertindole is metabolized by cytochrome P450 isoenzymes CYP 2D6 and CYP 3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sertindol Sertindole Sertindolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sertindole is an atypical antipsychotic indicated in the treatment of schizophrenia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Sertraline interact?

•Drug A: Abatacept •Drug B: Sertraline •Severity: MODERATE •Description: The metabolism of Sertraline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sertraline is indicated for the management of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), panic disorder (PD), premenstrual dysphoric disorder (PMDD), and social anxiety disorder (SAD). Common off-label uses for sertraline include the prevention of post stroke depression, generalized anxiety disorder (GAD), fibromyalgia, premature ejaculation, migraine prophylaxis, diabetic neuropathy, and neurocardiogenic syncope. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sertraline improves or relieves the symptoms of depression, OCD, post-traumatic stress disorder, obsessive-compulsive disorder, panic disorder, and premenstrual dysphoric disorder via the inhibition of serotonin reuptake. Clinical studies have shown that it improves cognition in depressed patients. It has less sedative, anticholinergic, and cardiovascular effects than the tricyclic antidepressant drugs because it does not exert significant anticholinergic, antihistamine, or adrenergic (alpha1, alpha2, beta) blocking activity. The onset of action and beneficial effects are usually noticed after 4-6 weeks, for reasons that are not fully understood and currently under investigation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sertraline selectively inhibits the reuptake of serotonin (5-HT) at the presynaptic neuronal membrane, thereby increasing serotonergic activity. This results in an increased synaptic concentration of serotonin in the CNS, which leads to numerous functional changes associated with enhanced serotonergic neurotransmission. These changes are believed to be responsible for the antidepressant action and beneficial effects in obsessive-compulsive (and other anxiety related disorders). It has been hypothesized that obsessive-compulsive disorder, like depression, is also caused by the disregulation of serotonin. In animal studies, chronic administration of sertraline results in down-regulation of brain norepinephrine receptors. Sertraline displays affinity for sigma-1 and 2 receptor binding sites, but binds with stronger affinity to sigma-1 binding sites. In vitro, sertraline shows little to no affinity for GABA, dopaminergic, serotonergic (5HT1A, 5HT1B, 5HT2), or benzodiazepine receptors. It exerts weak inhibitory actions on the neuronal uptake of norepinephrine and dopamine and exhibits no inhibitory effects on the monoamine oxidase enzyme. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following once-daily administration of 50 to 200 mg for two weeks, the mean peak plasma concentrations (Cmax) of sertraline occurred between 4.5 to 8.4 hours after administration, and measured at 20 to 55 μg/L. Steady-state concentrations are reached after 1 week following once-daily administration, and vary greatly depending on the patient. Bioavailability has been estimated to be above 44%. The area under the curve in healthy volunteers after a 100mg dose of sertraline was 456 μg × h/mL in one study. Effects of food on absorption The effects of food on the bioavailability of the sertraline tablet and oral concentrate were studied in subjects given a single dose with and without food. For the tablet, AUC was slightly increased when sertraline was administered with food, the Cmax was 25% greater, and the time to peak plasma concentration was shortened by about 2.5 hours. For the oral concentrate preparation of sertraline, peak concentration was prolonged by approximately 1 hour with the ingestion of food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Sertraline is widely distributed, and its volume of distribution is estimated to be more than 20L/kg. Post-mortem studies in humans have measured liver tissue concentrations of 3.9–20 mg/kg for sertraline and between 1.4 to 11 mg/kg for its active metabolite, N-desmethyl-sertraline (DMS). Studies have also determined sertraline distributes into the brain, plasma, and serum. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sertraline is highly bound to serum proteins, at about 98%-99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sertraline is heavily metabolized in the liver and has one major active metabolite. It undergoes N-demethylation to form N-desmethylsertraline, which is much less potent in its pharmacological activity than sertraline. In addition to N-demethylation, sertraline metabolism involves N-hydroxylation, oxidative deamination, and finally, glucuronidation. The metabolism of sertraline is mainly catalyzed by CYP3A4 and CYP2B6, with some activity accounted for by CYP2C19 and CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Since sertraline is extensively metabolized, excretion of unchanged drug in the urine is a minor route of elimination, with 12-14% of unchanged sertraline excreted in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of sertraline is approximately 26 hours. One reference mentions an elimination half-life ranging from 22-36 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In pharmacokinetic studies, the clearance of a 200mg dose of sertraline in studies of both young and elderly patients ranged between 1.09 ± 0.38 L/h/kg - 1.35 ± 0.67 L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD50 of sertraline is >2000 mg/kg in rats according to the FDA label. One other references indicates an oral LD50 of in mice and rats of 419 - 548 mg/kg and 1327 - 1591mg/kg, respectively. The most common signs and symptoms associated with a non-fatal sertraline overdose are somnolence, vomiting, tachycardia, nausea, dizziness, agitation, and tremor. No cases of fatal overdose with only sertraline have been reported. Most fatal cases are associated with the ingestion of sertraline with other drugs. Consequences of a sertraline overdose may include serotonin syndrome, hypertension, hypotension, syncope, stupor, coma, bradycardia, bundle branch block, QT-prolongation, torsade de pointes, delirium, hallucinations, and pancreatitis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zoloft •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sertralina Sertraline Sertralinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sertraline is a selective serotonin reuptake inhibitor (SSRI) indicated to treat major depressive disorder, social anxiety disorder and many other psychiatric conditions.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sertraline interact? Information: •Drug A: Abatacept •Drug B: Sertraline •Severity: MODERATE •Description: The metabolism of Sertraline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sertraline is indicated for the management of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), panic disorder (PD), premenstrual dysphoric disorder (PMDD), and social anxiety disorder (SAD). Common off-label uses for sertraline include the prevention of post stroke depression, generalized anxiety disorder (GAD), fibromyalgia, premature ejaculation, migraine prophylaxis, diabetic neuropathy, and neurocardiogenic syncope. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sertraline improves or relieves the symptoms of depression, OCD, post-traumatic stress disorder, obsessive-compulsive disorder, panic disorder, and premenstrual dysphoric disorder via the inhibition of serotonin reuptake. Clinical studies have shown that it improves cognition in depressed patients. It has less sedative, anticholinergic, and cardiovascular effects than the tricyclic antidepressant drugs because it does not exert significant anticholinergic, antihistamine, or adrenergic (alpha1, alpha2, beta) blocking activity. The onset of action and beneficial effects are usually noticed after 4-6 weeks, for reasons that are not fully understood and currently under investigation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sertraline selectively inhibits the reuptake of serotonin (5-HT) at the presynaptic neuronal membrane, thereby increasing serotonergic activity. This results in an increased synaptic concentration of serotonin in the CNS, which leads to numerous functional changes associated with enhanced serotonergic neurotransmission. These changes are believed to be responsible for the antidepressant action and beneficial effects in obsessive-compulsive (and other anxiety related disorders). It has been hypothesized that obsessive-compulsive disorder, like depression, is also caused by the disregulation of serotonin. In animal studies, chronic administration of sertraline results in down-regulation of brain norepinephrine receptors. Sertraline displays affinity for sigma-1 and 2 receptor binding sites, but binds with stronger affinity to sigma-1 binding sites. In vitro, sertraline shows little to no affinity for GABA, dopaminergic, serotonergic (5HT1A, 5HT1B, 5HT2), or benzodiazepine receptors. It exerts weak inhibitory actions on the neuronal uptake of norepinephrine and dopamine and exhibits no inhibitory effects on the monoamine oxidase enzyme. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following once-daily administration of 50 to 200 mg for two weeks, the mean peak plasma concentrations (Cmax) of sertraline occurred between 4.5 to 8.4 hours after administration, and measured at 20 to 55 μg/L. Steady-state concentrations are reached after 1 week following once-daily administration, and vary greatly depending on the patient. Bioavailability has been estimated to be above 44%. The area under the curve in healthy volunteers after a 100mg dose of sertraline was 456 μg × h/mL in one study. Effects of food on absorption The effects of food on the bioavailability of the sertraline tablet and oral concentrate were studied in subjects given a single dose with and without food. For the tablet, AUC was slightly increased when sertraline was administered with food, the Cmax was 25% greater, and the time to peak plasma concentration was shortened by about 2.5 hours. For the oral concentrate preparation of sertraline, peak concentration was prolonged by approximately 1 hour with the ingestion of food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Sertraline is widely distributed, and its volume of distribution is estimated to be more than 20L/kg. Post-mortem studies in humans have measured liver tissue concentrations of 3.9–20 mg/kg for sertraline and between 1.4 to 11 mg/kg for its active metabolite, N-desmethyl-sertraline (DMS). Studies have also determined sertraline distributes into the brain, plasma, and serum. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sertraline is highly bound to serum proteins, at about 98%-99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sertraline is heavily metabolized in the liver and has one major active metabolite. It undergoes N-demethylation to form N-desmethylsertraline, which is much less potent in its pharmacological activity than sertraline. In addition to N-demethylation, sertraline metabolism involves N-hydroxylation, oxidative deamination, and finally, glucuronidation. The metabolism of sertraline is mainly catalyzed by CYP3A4 and CYP2B6, with some activity accounted for by CYP2C19 and CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Since sertraline is extensively metabolized, excretion of unchanged drug in the urine is a minor route of elimination, with 12-14% of unchanged sertraline excreted in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of sertraline is approximately 26 hours. One reference mentions an elimination half-life ranging from 22-36 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In pharmacokinetic studies, the clearance of a 200mg dose of sertraline in studies of both young and elderly patients ranged between 1.09 ± 0.38 L/h/kg - 1.35 ± 0.67 L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD50 of sertraline is >2000 mg/kg in rats according to the FDA label. One other references indicates an oral LD50 of in mice and rats of 419 - 548 mg/kg and 1327 - 1591mg/kg, respectively. The most common signs and symptoms associated with a non-fatal sertraline overdose are somnolence, vomiting, tachycardia, nausea, dizziness, agitation, and tremor. No cases of fatal overdose with only sertraline have been reported. Most fatal cases are associated with the ingestion of sertraline with other drugs. Consequences of a sertraline overdose may include serotonin syndrome, hypertension, hypotension, syncope, stupor, coma, bradycardia, bundle branch block, QT-prolongation, torsade de pointes, delirium, hallucinations, and pancreatitis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zoloft •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sertralina Sertraline Sertralinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sertraline is a selective serotonin reuptake inhibitor (SSRI) indicated to treat major depressive disorder, social anxiety disorder and many other psychiatric conditions. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Sevoflurane interact?

•Drug A: Abatacept •Drug B: Sevoflurane •Severity: MODERATE •Description: The metabolism of Sevoflurane can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sevoflurane is used for the induction and maintenance of general anesthesia in adult and pediatric patients for inpatient and outpatient surgery. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sevoflurane induces muscle relaxation and reduces sensitivity by altering tissue excitability with a fast onset of action. It does so by decreasing the extent of gap junction-mediated cell-cell coupling and altering the activity of the channels that underlie the action potential. Compared to halothane and isoflurane, sevoflurane has a shorter emergence time, as well as a shorter time to first analgesia. To reach an equilibrium between alveolar and arterial partial pressure, only a minimal amount of sevoflurane needs to be dissolved in blood. The use of sevoflurane can increase the risk of renal injury, respiratory depression, and QT prolongation. Also, it can lead to malignant hyperthermia, perioperative hyperkalemia, and pediatric neurotoxicity. Episodes of severe bradycardia and cardiac arrest have been reported in pediatric patients with Down Syndrome given sevoflurane. Sevoflurane anesthesia may impair the performance of activities requiring mental alertness, such as driving or operating machinery. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of action of sevoflurane has not been fully elucidated. Like other halogenated inhalational anesthetics, sevoflurane induces anesthesia by binding to ligand-gated ion channels and blocking CNS neurotransmission. It has been suggested that inhaled anesthetics enhance inhibitory postsynaptic channel activity by binding GABA A and glycine receptors, and inhibit excitatory synaptic channel activity by binding nicotinic acetylcholine, serotonin, and glutamate receptors. Sevoflurane has an effect on several ionic currents, including the hyperpolarisation-activated cation current (I f ), the T-type and L-type Ca currents (I Ca, T and I Ca, L ), the slowly activating delayed rectifier K currents (I Ks ), and the Na /Ca exchange current (I NCX ). This ability to modulate ion channel activity can also regulate cardiac excitability and contractility. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sevoflurane is rapidly absorbed into circulation through the lungs; however, solubility in the blood is low (blood/gas partition coefficient at 37°C ranges from 0.63 to 0.69). Therefore, a minimal amount of sevoflurane needs to be dissolved in blood in order to induce anesthesia. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Patients given low-flow sevoflurane anesthesia during maxillofacial surgery (n=16) had a peripheral volume of distribution of 1634 ml vapour /kg bw and a total volume of distribution of 1748 ml vapour /kg bw. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sevoflurane protein binding has not been evaluated. In vitro analyses have shown that other fluorinated volatile anesthetics can displace drugs from serum and tissue proteins; however, it is unclear if this is clinically significant. Clinical studies have shown that the administration of sevoflurane does not have a significant effect in patients taking drugs that are highly bound and have a small volume of distribution. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sevoflurane is metabolized to hexafluoroisopropanol by cytochrome P450 2E1 in a reaction that promotes the release of inorganic fluoride and carbon dioxide. Hexafluoroisopropanol is rapidly conjugated with glucuronic acid and eliminated in urine. In vivo metabolism studies suggest that approximately 5% of the sevoflurane dose may be metabolized. In most cases, inorganic fluoride reaches its highest concentration within 2 hours of the end of sevoflurane anesthesia, and returns to baseline levels within 48 hours. Sevoflurane metabolism may be induced by chronic exposure to isoniazid and ethanol, and it has been shown that barbiturates do not affect it. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The low solubility of sevoflurane facilitates its rapid elimination through the lungs, where 95% to 98% of this anesthetic is eliminated. Up to 3.5% of the sevoflurane dose appears in urine as inorganic fluoride, and as much as 50% of fluoride clearance is nonrenal (fluoride taken up into bone). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of sevoflurane from the peripheral fat compartment is approximately 20 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients given low-flow sevoflurane anaesthesia during maxillofacial surgery (n=16), the transport clearance from the central to the peripheral compartment was 13.0 ml vapour /kg bw ⋅min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of sevoflurane overdosage (or what may appear to be overdosage) discontinue administration, maintain a patent airway, initiate assisted or controlled ventilation with oxygen, and maintain adequate cardiovascular function. Patients experiencing an overdose may be at an increased risk of severe adverse effects such as renal injury, respiratory depression, severe bradycardia and cardiac arrest. Fatalities due to sevoflurane abuse have been reported as well. Symptomatic and supportive measures are recommended. Animal studies have shown that the use of anesthetic agents during periods of rapid brain growth or synaptogenesis results in alterations in synaptic morphology and neurogenesis. In primates, anesthetic regimens of up to 3 hours did not increase neuronal cell loss, but regimens of 5 hours or longer did have a significant effect. The oral LD 50 of sevoflurane is 10.8 g/kg in rats and 18.2 g/kg in mice. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sevorane, Sojourn, Ultane •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sevofluran Sevoflurane Sevoflurano Sevofluranum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sevoflurane is a inhalation anaesthetic agent used for induction and maintenance of general anesthesia during surgical procedures.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sevoflurane interact? Information: •Drug A: Abatacept •Drug B: Sevoflurane •Severity: MODERATE •Description: The metabolism of Sevoflurane can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sevoflurane is used for the induction and maintenance of general anesthesia in adult and pediatric patients for inpatient and outpatient surgery. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sevoflurane induces muscle relaxation and reduces sensitivity by altering tissue excitability with a fast onset of action. It does so by decreasing the extent of gap junction-mediated cell-cell coupling and altering the activity of the channels that underlie the action potential. Compared to halothane and isoflurane, sevoflurane has a shorter emergence time, as well as a shorter time to first analgesia. To reach an equilibrium between alveolar and arterial partial pressure, only a minimal amount of sevoflurane needs to be dissolved in blood. The use of sevoflurane can increase the risk of renal injury, respiratory depression, and QT prolongation. Also, it can lead to malignant hyperthermia, perioperative hyperkalemia, and pediatric neurotoxicity. Episodes of severe bradycardia and cardiac arrest have been reported in pediatric patients with Down Syndrome given sevoflurane. Sevoflurane anesthesia may impair the performance of activities requiring mental alertness, such as driving or operating machinery. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of action of sevoflurane has not been fully elucidated. Like other halogenated inhalational anesthetics, sevoflurane induces anesthesia by binding to ligand-gated ion channels and blocking CNS neurotransmission. It has been suggested that inhaled anesthetics enhance inhibitory postsynaptic channel activity by binding GABA A and glycine receptors, and inhibit excitatory synaptic channel activity by binding nicotinic acetylcholine, serotonin, and glutamate receptors. Sevoflurane has an effect on several ionic currents, including the hyperpolarisation-activated cation current (I f ), the T-type and L-type Ca currents (I Ca, T and I Ca, L ), the slowly activating delayed rectifier K currents (I Ks ), and the Na /Ca exchange current (I NCX ). This ability to modulate ion channel activity can also regulate cardiac excitability and contractility. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sevoflurane is rapidly absorbed into circulation through the lungs; however, solubility in the blood is low (blood/gas partition coefficient at 37°C ranges from 0.63 to 0.69). Therefore, a minimal amount of sevoflurane needs to be dissolved in blood in order to induce anesthesia. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Patients given low-flow sevoflurane anesthesia during maxillofacial surgery (n=16) had a peripheral volume of distribution of 1634 ml vapour /kg bw and a total volume of distribution of 1748 ml vapour /kg bw. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sevoflurane protein binding has not been evaluated. In vitro analyses have shown that other fluorinated volatile anesthetics can displace drugs from serum and tissue proteins; however, it is unclear if this is clinically significant. Clinical studies have shown that the administration of sevoflurane does not have a significant effect in patients taking drugs that are highly bound and have a small volume of distribution. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sevoflurane is metabolized to hexafluoroisopropanol by cytochrome P450 2E1 in a reaction that promotes the release of inorganic fluoride and carbon dioxide. Hexafluoroisopropanol is rapidly conjugated with glucuronic acid and eliminated in urine. In vivo metabolism studies suggest that approximately 5% of the sevoflurane dose may be metabolized. In most cases, inorganic fluoride reaches its highest concentration within 2 hours of the end of sevoflurane anesthesia, and returns to baseline levels within 48 hours. Sevoflurane metabolism may be induced by chronic exposure to isoniazid and ethanol, and it has been shown that barbiturates do not affect it. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The low solubility of sevoflurane facilitates its rapid elimination through the lungs, where 95% to 98% of this anesthetic is eliminated. Up to 3.5% of the sevoflurane dose appears in urine as inorganic fluoride, and as much as 50% of fluoride clearance is nonrenal (fluoride taken up into bone). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of sevoflurane from the peripheral fat compartment is approximately 20 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients given low-flow sevoflurane anaesthesia during maxillofacial surgery (n=16), the transport clearance from the central to the peripheral compartment was 13.0 ml vapour /kg bw ⋅min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of sevoflurane overdosage (or what may appear to be overdosage) discontinue administration, maintain a patent airway, initiate assisted or controlled ventilation with oxygen, and maintain adequate cardiovascular function. Patients experiencing an overdose may be at an increased risk of severe adverse effects such as renal injury, respiratory depression, severe bradycardia and cardiac arrest. Fatalities due to sevoflurane abuse have been reported as well. Symptomatic and supportive measures are recommended. Animal studies have shown that the use of anesthetic agents during periods of rapid brain growth or synaptogenesis results in alterations in synaptic morphology and neurogenesis. In primates, anesthetic regimens of up to 3 hours did not increase neuronal cell loss, but regimens of 5 hours or longer did have a significant effect. The oral LD 50 of sevoflurane is 10.8 g/kg in rats and 18.2 g/kg in mice. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sevorane, Sojourn, Ultane •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sevofluran Sevoflurane Sevoflurano Sevofluranum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sevoflurane is a inhalation anaesthetic agent used for induction and maintenance of general anesthesia during surgical procedures. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Does Abatacept and Sildenafil interact?

•Drug A: Abatacept •Drug B: Sildenafil •Severity: MODERATE •Description: The metabolism of Sildenafil can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor that is predominantly employed for two primary indications: (1) the treatment of erectile dysfunction; and (2) treatment of pulmonary hypertension, where: a) the US FDA specifically indicates sildenafil for the treatment of pulmonary arterial hypertension (PAH) (WHO Group I) in adults to improve exercise ability and delay clinical worsening. The delay in clinical worsening was demonstrated when sildenafil was added to background epoprostenol therapy. Studies establishing effectiveness were short-term (12 to 16 weeks), and included predominately patients with New York Heart Association (NYHA) Functional Class II-III symptoms and idiopathic etiology (71%) or associated with connective tissue disease (CTD) (25%); b) the Canadian product monograph specifically indicates sildenafil for the treatment of primary pulmonary arterial hypertension (PPH) or pulmonary hypertension secondary to connective tissue disease (CTD) in adult patients with WHO functional class II or III who have not responded to conventional therapy. In addition, improvement in exercise ability and delay in clinical worsening was demonstrated in adult patients who were already stabilized on background epoprostenol therapy; and c) the EMA product information specifically indicates sildenafil for the treatment of adult patients with pulmonary arterial hypertension classified as WHO functional class II and III, to improve exercise capacity. Efficacy has been shown in primary pulmonary hypertension and pulmonary hypertension associated with connective tissue disease. The EMA label also indicates sildenafil for the treatment of pediatric patients aged 1 year to 17 years old with pulmonary arterial hypertension. Efficacy in terms of improvement of exercise capacity or pulmonary hemodynamics has been shown in primary pulmonary hypertension and pulmonary hypertension associated with congenital heart disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro studies have shown that sildenafil is selective for phosphodiesterase-5 (PDE5). Its effect is more potent on PDE5 than on other known phosphodiesterases. In particular, there is a 10-times selectivity over PDE6 which is involved in the phototransduction pathway in the retina. There is an 80-times selectivity over PDE1, and over 700-times over PDE 2, 3, 4, 7, 8, 9, 10 and 11. And finally, sildenafil has greater than 4,000-times selectivity for PDE5 over PDE3, the cAMP-specific phosphodiesterase isoform involved in the control of cardiac contractility. In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (via the use of RigiScan®), after sildenafil administration compared with placebo. Most studies assessed the efficacy of sildenafil approximately 60 minutes post-dose. The erectile response, as assessed by RigiScan®, generally increased with increasing sildenafil dose and plasma concentration. The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours. Sildenafil causes mild and transient decreases in systemic blood pressure which, in the majority of cases, do not translate into clinical effects. After chronic dosing of 80 mg, three times a day to patients with systemic hypertension the mean change from baseline in systolic and diastolic blood pressure was a decrease of 9.4 mmHg and 9.1 mmHg respectively. After chronic dosing of 80 mg, three times a day to patients with pulmonary arterial hypertension lesser effects in blood pressure reduction were observed (a reduction in both systolic and diastolic pressure of 2 mmHg). At the recommended dose of 20 mg three times a day no reductions in systolic or diastolic pressure were seen. Single oral doses of sildenafil up to 100 mg in healthy volunteers produced no clinically relevant effects on ECG. After chronic dosing of 80 mg three times a day to patients with pulmonary arterial hypertension no clinically relevant effects on the ECG were reported either. In a study of the hemodynamic effects of a single oral 100 mg dose of sildenafil in 14 patients with severe coronary artery disease (CAD) (> 70 % stenosis of at least one coronary artery), the mean resting systolic and diastolic blood pressures decreased by 7 % and 6 % respectively compared to baseline. Mean pulmonary systolic blood pressure decreased by 9%. Sildenafil showed no effect on cardiac output and did not impair blood flow through the stenosed coronary arteries. Mild and transient differences in color discrimination (blue/green) were detected in some subjects using the Farnsworth-Munsell 100 hue test at 1 hour following a 100 mg dose, with no effects evident after 2 hours post-dose. The postulated mechanism for this change in color discrimination is related to inhibition of PDE6, which is involved in the phototransduction cascade of the retina. Sildenafil has no effect on visual acuity or contrast sensitivity. In a small size placebo-controlled study of patients with documented early age-related macular degeneration (n = 9), sildenafil (single dose, 100 mg) demonstrated no significant changes in visual tests conducted (which included visual acuity, Amsler grid, color discrimination simulated traffic light, and the Humphrey perimeter and photostress test). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sildenafil is an oral therapy for erectile dysfunction. In the natural setting, i.e. with sexual stimulation, it restores impaired erectile function by increasing blood flow to the penis. The physiological mechanism responsible for the erection of the penis involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. Nitric oxide then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) in the corpus cavernosum, where PDE5 is responsible for degradation of cGMP. Sildenafil has a peripheral site of action on erections. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum but potently enhances the relaxant effect of NO on this tissue. When the NO/cGMP pathway is activated, as occurs with sexual stimulation, inhibition of PDE5 by sildenafil results in increased corpus cavernosum levels of cGMP. Therefore sexual stimulation is required in order for sildenafil to produce its intended beneficial pharmacological effects. Moreover, apart from the presence of PDE5 in the corpus cavernosum of the penis, PDE5 is also present in the pulmonary vasculature. Sildenafil, therefore, increases cGMP within pulmonary vascular smooth muscle cells resulting in relaxation. In patients with pulmonary arterial hypertension, this can lead to vasodilation of the pulmonary vascular bed and, to a lesser degree, vasodilatation in the systemic circulation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sildenafil is known to be quickly absorbed, with maximum plasma concentrations being observed within 30-120 minutes (with a median of 60 minutes) of oral administration in a fasting patient. Moreover, the mean absolute bioavailability observed for sildenafil is about 41% (from a range of 25-63%). In particular, after oral three times a day dosing of sildenafil, the AUC and Cmax increase in proportion with dose over the recommended dosage range of 25-100 mg. When used in pulmonary arterial hypertension patients, however, the oral bioavailability of sildenafil after a dosing regimen of 80 mg three times a day, was on average 43% greater than compared to the lower doses. Finally, if sildenafil is administered orally with food, the rate of absorption is observed to be decreased with a mean delay in Tmax of about 60 minutes and a mean decrease in Cmax of approximately 29%. Regardless, the extent of absorption is not observed to be significantly affected as the recorded AUC decreased by only about 11 %. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean steady-state volume of distribution documented for sildenafil is approximately 105 L - a value which suggests the medication undergoes distribution into the tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): It is generally observed that sildenafil and its main circulating N-desmethyl metabolite are both estimated to be about 96% bound to plasma proteins. Nevertheless, it has been determined that protein binding for sildenafil is independent of total drug concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of sildenafil is facilitated primarily by the CYP3A4 hepatic microsomal isoenzymes and to a minor extent, via the CYP2C9 hepatic isoenzymes. The predominant circulating metabolite results from the N-demethylation of sildenafil. This particular resultant metabolite possesses a phosphodiesterase selectivity that is similar to the parent sildenafil molecule and a corresponding in vitro potency for PDE5 that is approximately 50% that of the parent drug. Moreover, plasma concentrations of the metabolite are about 40% of those recorded for sildenafil, a percentage that accounts for about 20% of sildenafil’s pharmacologic effects. This primary N-desmethyl metabolite of sildenafil also undergoes further metabolism, with a terminal half-life of about 4 hours. In patients with pulmonary arterial hypertension, plasma concentrations of the primary N-desmethyl metabolite are about 72% those of the original parent sildenafil molecule after a regimen of 20 mg three times a day - which is consequently responsible for about a 36% contribution to sildenafil’s overall pharmacological effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After either oral or intravenous administration, sildenafil is excreted as metabolites predominantly in the feces (approximately 80% of the administered oral dose) and to a lesser extent in the urine (approximately 13% of the administered oral dose). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal phase half-life observed for sildenafil is approximately 3 to 5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total body clearance documented for sildenafil is 41 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In single-dose volunteer studies of doses up to 800 mg, adverse reactions were similar to those seen at lower doses, but the incidence rates and severities were increased. Doses of 200 mg did not result in increased efficacy but the incidence of adverse reaction (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased. Due to the lack of data on the effect of sildenafil indicated for the treatment of pulmonary arterial hypertension (PAH) in pregnant women, sildenafil is not recommended for women of childbearing potential unless also using appropriate contraceptive measures. The safety and efficacy of sildenafil indicated for treating PAH in a woman during labor and delivery have not been studied. Caution should ultimately be exercised when sildenafil is administered to nursing women as it is not known if sildenafil or its metabolites are excreted in human breast milk. The safety and efficacy of sildenafil for the treatment of PAH in children below 1 year of age has not been established as no data is available. Clinical experience with the elderly population in the use of sildenafil for the treatment of PAH has been varied. Some reports suggest that there are no identified differences in responses between elderly and younger patients while others have documented that clinical efficacy as measured by 6-minute walk distance could be less in elderly patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Conversely, when sildenafil was used to treat erectile dysfunction in healthy elderly volunteers (65 years or over), a reduced clearance of sildenafil was observed. This reduction resulted in about 90% higher plasma concentrations of sildenafil and the active N-desmethyl metabolite compared to those seen in healthy younger volunteers (18-45 years). Due to age-differences in plasma protein binding, the corresponding increase in free sildenafil plasma concentration was approximately 40%. Sildenafil was not carcinogenic when administered to rats for 24 months at a dose resulting in total systemic drug exposure (AUCs) for unbound sildenafil and its major metabolite of 29- and 42- times, for male and female rats, respectively, the exposures observed in human males given the Maximum Recommended Human Dose (MRHD) of 100 mg. Sildenafil was not carcinogenic when administered to mice for 18-21 months at dosages up to the Maximum Tolerated Dose (MTD) of 10 mg/kg/day, approximately 0.6 times the MRHD on a mg/m2 basis. Sildenafil was negative in in vitro bacterial and Chinese hamster ovary cell assays to detect mutagenicity, and in vitro human lymphocytes and in vivo mouse micronucleus assays to detect clastogenicity. There was no impairment of fertility in rats given sildenafil up to 60 mg/kg/day for 36 days to females and 102 days to males, a dose producing an AUC value of more than 25 times the human male AUC. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Liqrev, Revatio, Viagra, Vizarsin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sildenafil Sildenafilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sildenafil is a phosphodiesterase inhibitor used for the treatment of erectile dysfunction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sildenafil interact? Information: •Drug A: Abatacept •Drug B: Sildenafil •Severity: MODERATE •Description: The metabolism of Sildenafil can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor that is predominantly employed for two primary indications: (1) the treatment of erectile dysfunction; and (2) treatment of pulmonary hypertension, where: a) the US FDA specifically indicates sildenafil for the treatment of pulmonary arterial hypertension (PAH) (WHO Group I) in adults to improve exercise ability and delay clinical worsening. The delay in clinical worsening was demonstrated when sildenafil was added to background epoprostenol therapy. Studies establishing effectiveness were short-term (12 to 16 weeks), and included predominately patients with New York Heart Association (NYHA) Functional Class II-III symptoms and idiopathic etiology (71%) or associated with connective tissue disease (CTD) (25%); b) the Canadian product monograph specifically indicates sildenafil for the treatment of primary pulmonary arterial hypertension (PPH) or pulmonary hypertension secondary to connective tissue disease (CTD) in adult patients with WHO functional class II or III who have not responded to conventional therapy. In addition, improvement in exercise ability and delay in clinical worsening was demonstrated in adult patients who were already stabilized on background epoprostenol therapy; and c) the EMA product information specifically indicates sildenafil for the treatment of adult patients with pulmonary arterial hypertension classified as WHO functional class II and III, to improve exercise capacity. Efficacy has been shown in primary pulmonary hypertension and pulmonary hypertension associated with connective tissue disease. The EMA label also indicates sildenafil for the treatment of pediatric patients aged 1 year to 17 years old with pulmonary arterial hypertension. Efficacy in terms of improvement of exercise capacity or pulmonary hemodynamics has been shown in primary pulmonary hypertension and pulmonary hypertension associated with congenital heart disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro studies have shown that sildenafil is selective for phosphodiesterase-5 (PDE5). Its effect is more potent on PDE5 than on other known phosphodiesterases. In particular, there is a 10-times selectivity over PDE6 which is involved in the phototransduction pathway in the retina. There is an 80-times selectivity over PDE1, and over 700-times over PDE 2, 3, 4, 7, 8, 9, 10 and 11. And finally, sildenafil has greater than 4,000-times selectivity for PDE5 over PDE3, the cAMP-specific phosphodiesterase isoform involved in the control of cardiac contractility. In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (via the use of RigiScan®), after sildenafil administration compared with placebo. Most studies assessed the efficacy of sildenafil approximately 60 minutes post-dose. The erectile response, as assessed by RigiScan®, generally increased with increasing sildenafil dose and plasma concentration. The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours. Sildenafil causes mild and transient decreases in systemic blood pressure which, in the majority of cases, do not translate into clinical effects. After chronic dosing of 80 mg, three times a day to patients with systemic hypertension the mean change from baseline in systolic and diastolic blood pressure was a decrease of 9.4 mmHg and 9.1 mmHg respectively. After chronic dosing of 80 mg, three times a day to patients with pulmonary arterial hypertension lesser effects in blood pressure reduction were observed (a reduction in both systolic and diastolic pressure of 2 mmHg). At the recommended dose of 20 mg three times a day no reductions in systolic or diastolic pressure were seen. Single oral doses of sildenafil up to 100 mg in healthy volunteers produced no clinically relevant effects on ECG. After chronic dosing of 80 mg three times a day to patients with pulmonary arterial hypertension no clinically relevant effects on the ECG were reported either. In a study of the hemodynamic effects of a single oral 100 mg dose of sildenafil in 14 patients with severe coronary artery disease (CAD) (> 70 % stenosis of at least one coronary artery), the mean resting systolic and diastolic blood pressures decreased by 7 % and 6 % respectively compared to baseline. Mean pulmonary systolic blood pressure decreased by 9%. Sildenafil showed no effect on cardiac output and did not impair blood flow through the stenosed coronary arteries. Mild and transient differences in color discrimination (blue/green) were detected in some subjects using the Farnsworth-Munsell 100 hue test at 1 hour following a 100 mg dose, with no effects evident after 2 hours post-dose. The postulated mechanism for this change in color discrimination is related to inhibition of PDE6, which is involved in the phototransduction cascade of the retina. Sildenafil has no effect on visual acuity or contrast sensitivity. In a small size placebo-controlled study of patients with documented early age-related macular degeneration (n = 9), sildenafil (single dose, 100 mg) demonstrated no significant changes in visual tests conducted (which included visual acuity, Amsler grid, color discrimination simulated traffic light, and the Humphrey perimeter and photostress test). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sildenafil is an oral therapy for erectile dysfunction. In the natural setting, i.e. with sexual stimulation, it restores impaired erectile function by increasing blood flow to the penis. The physiological mechanism responsible for the erection of the penis involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. Nitric oxide then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) in the corpus cavernosum, where PDE5 is responsible for degradation of cGMP. Sildenafil has a peripheral site of action on erections. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum but potently enhances the relaxant effect of NO on this tissue. When the NO/cGMP pathway is activated, as occurs with sexual stimulation, inhibition of PDE5 by sildenafil results in increased corpus cavernosum levels of cGMP. Therefore sexual stimulation is required in order for sildenafil to produce its intended beneficial pharmacological effects. Moreover, apart from the presence of PDE5 in the corpus cavernosum of the penis, PDE5 is also present in the pulmonary vasculature. Sildenafil, therefore, increases cGMP within pulmonary vascular smooth muscle cells resulting in relaxation. In patients with pulmonary arterial hypertension, this can lead to vasodilation of the pulmonary vascular bed and, to a lesser degree, vasodilatation in the systemic circulation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sildenafil is known to be quickly absorbed, with maximum plasma concentrations being observed within 30-120 minutes (with a median of 60 minutes) of oral administration in a fasting patient. Moreover, the mean absolute bioavailability observed for sildenafil is about 41% (from a range of 25-63%). In particular, after oral three times a day dosing of sildenafil, the AUC and Cmax increase in proportion with dose over the recommended dosage range of 25-100 mg. When used in pulmonary arterial hypertension patients, however, the oral bioavailability of sildenafil after a dosing regimen of 80 mg three times a day, was on average 43% greater than compared to the lower doses. Finally, if sildenafil is administered orally with food, the rate of absorption is observed to be decreased with a mean delay in Tmax of about 60 minutes and a mean decrease in Cmax of approximately 29%. Regardless, the extent of absorption is not observed to be significantly affected as the recorded AUC decreased by only about 11 %. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean steady-state volume of distribution documented for sildenafil is approximately 105 L - a value which suggests the medication undergoes distribution into the tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): It is generally observed that sildenafil and its main circulating N-desmethyl metabolite are both estimated to be about 96% bound to plasma proteins. Nevertheless, it has been determined that protein binding for sildenafil is independent of total drug concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of sildenafil is facilitated primarily by the CYP3A4 hepatic microsomal isoenzymes and to a minor extent, via the CYP2C9 hepatic isoenzymes. The predominant circulating metabolite results from the N-demethylation of sildenafil. This particular resultant metabolite possesses a phosphodiesterase selectivity that is similar to the parent sildenafil molecule and a corresponding in vitro potency for PDE5 that is approximately 50% that of the parent drug. Moreover, plasma concentrations of the metabolite are about 40% of those recorded for sildenafil, a percentage that accounts for about 20% of sildenafil’s pharmacologic effects. This primary N-desmethyl metabolite of sildenafil also undergoes further metabolism, with a terminal half-life of about 4 hours. In patients with pulmonary arterial hypertension, plasma concentrations of the primary N-desmethyl metabolite are about 72% those of the original parent sildenafil molecule after a regimen of 20 mg three times a day - which is consequently responsible for about a 36% contribution to sildenafil’s overall pharmacological effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After either oral or intravenous administration, sildenafil is excreted as metabolites predominantly in the feces (approximately 80% of the administered oral dose) and to a lesser extent in the urine (approximately 13% of the administered oral dose). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal phase half-life observed for sildenafil is approximately 3 to 5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total body clearance documented for sildenafil is 41 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In single-dose volunteer studies of doses up to 800 mg, adverse reactions were similar to those seen at lower doses, but the incidence rates and severities were increased. Doses of 200 mg did not result in increased efficacy but the incidence of adverse reaction (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased. Due to the lack of data on the effect of sildenafil indicated for the treatment of pulmonary arterial hypertension (PAH) in pregnant women, sildenafil is not recommended for women of childbearing potential unless also using appropriate contraceptive measures. The safety and efficacy of sildenafil indicated for treating PAH in a woman during labor and delivery have not been studied. Caution should ultimately be exercised when sildenafil is administered to nursing women as it is not known if sildenafil or its metabolites are excreted in human breast milk. The safety and efficacy of sildenafil for the treatment of PAH in children below 1 year of age has not been established as no data is available. Clinical experience with the elderly population in the use of sildenafil for the treatment of PAH has been varied. Some reports suggest that there are no identified differences in responses between elderly and younger patients while others have documented that clinical efficacy as measured by 6-minute walk distance could be less in elderly patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Conversely, when sildenafil was used to treat erectile dysfunction in healthy elderly volunteers (65 years or over), a reduced clearance of sildenafil was observed. This reduction resulted in about 90% higher plasma concentrations of sildenafil and the active N-desmethyl metabolite compared to those seen in healthy younger volunteers (18-45 years). Due to age-differences in plasma protein binding, the corresponding increase in free sildenafil plasma concentration was approximately 40%. Sildenafil was not carcinogenic when administered to rats for 24 months at a dose resulting in total systemic drug exposure (AUCs) for unbound sildenafil and its major metabolite of 29- and 42- times, for male and female rats, respectively, the exposures observed in human males given the Maximum Recommended Human Dose (MRHD) of 100 mg. Sildenafil was not carcinogenic when administered to mice for 18-21 months at dosages up to the Maximum Tolerated Dose (MTD) of 10 mg/kg/day, approximately 0.6 times the MRHD on a mg/m2 basis. Sildenafil was negative in in vitro bacterial and Chinese hamster ovary cell assays to detect mutagenicity, and in vitro human lymphocytes and in vivo mouse micronucleus assays to detect clastogenicity. There was no impairment of fertility in rats given sildenafil up to 60 mg/kg/day for 36 days to females and 102 days to males, a dose producing an AUC value of more than 25 times the human male AUC. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Liqrev, Revatio, Viagra, Vizarsin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sildenafil Sildenafilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sildenafil is a phosphodiesterase inhibitor used for the treatment of erectile dysfunction. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Siltuximab interact?

•Drug A: Abatacept •Drug B: Siltuximab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Siltuximab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Siltuximab is indicated for the treatment of patients with multicentric Castleman's disease (MCD) who are human immunodeficiency virus (HIV) negative and human herpesvirus-8 (HHV-8) negative. Siltuximab did not bind to virally produced IL-6 in a nonclinical study and was therefore not studied in patients with MCD who are HIV or HHV-8 positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Siltuximab-neutralized antibody-IL-6 complexes interfere with current immunological-based IL-6 quantification methods, therefore measurement of serum or plasma IL-6 concentrations should not be used as a pharmacodynamic marker during treatment. As well, cytochrome P450 enzymes in the liver are down regulated by infection and inflammation stimuli, which includes cytokines such as IL-6. By preventing IL-6 signalling through treatment with siltuximab, CYP450 activity may be increased leading to faster metabolism of drugs that are CYP450 substrates. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Siltuximab complexes with human IL-6 and prevents binding to soluble and membrane-bound IL-6 receptors, thereby inhibiting the proliferation of lymphocytes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on population pharmacokinetic analysis, the central volume of distribution in a male subject with body weight of 70 kg is 4.5 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As siltuximab is an antibody, the expected consequence of metabolism is proteolytic degradation to small peptides and individual amino acids, and receptor-mediated clearance. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half life after the first intravenous infusion of 11 mg/kg is 20.6 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Body weight was identified as the only statistically significant covariate of siltuximab clearance, therefore body weight based dosing is appropriate. Based on population pharmacokinetic analysis, the clearance of situximab in patients is 0.23 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common side effects that occurred during siltuximab treatment were pruritis, increased weight, rash, hyperuricemia, and upper respiratory tract infection. Siltuximab should not be administered to patients with severe infections as it may mask signs and symptoms of acute inflammation including suppression of fever and acute phase reactants such as C-reactive protein (CRP). Gastrointestinal perforation has been reported in clinical trials, therefore use with caution in patients who may be at increased risk for GI perforation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sylvant •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Siltuximab is an interleukin antagonist used to treat multicentric Castleman's disease (MCD) in patients who are HIV and HHV-8 negative.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Siltuximab interact? Information: •Drug A: Abatacept •Drug B: Siltuximab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Siltuximab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Siltuximab is indicated for the treatment of patients with multicentric Castleman's disease (MCD) who are human immunodeficiency virus (HIV) negative and human herpesvirus-8 (HHV-8) negative. Siltuximab did not bind to virally produced IL-6 in a nonclinical study and was therefore not studied in patients with MCD who are HIV or HHV-8 positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Siltuximab-neutralized antibody-IL-6 complexes interfere with current immunological-based IL-6 quantification methods, therefore measurement of serum or plasma IL-6 concentrations should not be used as a pharmacodynamic marker during treatment. As well, cytochrome P450 enzymes in the liver are down regulated by infection and inflammation stimuli, which includes cytokines such as IL-6. By preventing IL-6 signalling through treatment with siltuximab, CYP450 activity may be increased leading to faster metabolism of drugs that are CYP450 substrates. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Siltuximab complexes with human IL-6 and prevents binding to soluble and membrane-bound IL-6 receptors, thereby inhibiting the proliferation of lymphocytes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on population pharmacokinetic analysis, the central volume of distribution in a male subject with body weight of 70 kg is 4.5 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As siltuximab is an antibody, the expected consequence of metabolism is proteolytic degradation to small peptides and individual amino acids, and receptor-mediated clearance. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half life after the first intravenous infusion of 11 mg/kg is 20.6 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Body weight was identified as the only statistically significant covariate of siltuximab clearance, therefore body weight based dosing is appropriate. Based on population pharmacokinetic analysis, the clearance of situximab in patients is 0.23 L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common side effects that occurred during siltuximab treatment were pruritis, increased weight, rash, hyperuricemia, and upper respiratory tract infection. Siltuximab should not be administered to patients with severe infections as it may mask signs and symptoms of acute inflammation including suppression of fever and acute phase reactants such as C-reactive protein (CRP). Gastrointestinal perforation has been reported in clinical trials, therefore use with caution in patients who may be at increased risk for GI perforation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sylvant •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Siltuximab is an interleukin antagonist used to treat multicentric Castleman's disease (MCD) in patients who are HIV and HHV-8 negative. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Simvastatin interact?

•Drug A: Abatacept •Drug B: Simvastatin •Severity: MODERATE •Description: The metabolism of Simvastatin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Simvastatin is indicated for the treatment of hyperlipidemia to reduce elevated total cholesterol (total-C), low-density lipoprotein cholesterol (LDL‑C), apolipoprotein B (Apo B), and triglycerides (TG), and to increase high-density lipoprotein cholesterol (HDL-C). This includes the treatment of primary hyperlipidemia (Fredrickson type IIa, heterozygous familial and nonfamilial), mixed dyslipidemia (Fredrickson type IIb), hypertriglyceridemia (Fredrickson type IV hyperlipidemia), primary dysbetalipoproteinemia (Fredrickson type III hyperlipidemia), homozygous familial hypercholesterolemia (HoFH) as an adjunct to other lipid-lowering treatments, as well as adolescent patients with Heterozygous Familial Hypercholesterolemia (HeFH). Simvastatin is also indicated to reduce the risk of cardiovascular morbidity and mortality including myocardial infarction, stroke, and the need for revascularization procedures. It is primarily used in patients at high risk of coronary events because of existing coronary heart disease, diabetes, peripheral vessel disease, history of stroke or other cerebrovascular disease. Prescribing of statin medications is considered standard practice following any cardiovascular events and for people with a moderate to high risk of development of CVD. Statin-indicated conditions include diabetes mellitus, clinical atherosclerosis (including myocardial infarction, acute coronary syndromes, stable angina, documented coronary artery disease, stroke, trans ischemic attack (TIA), documented carotid disease, peripheral artery disease, and claudication), abdominal aortic aneurysm, chronic kidney disease, and severely elevated LDL-C levels. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Simvastatin is an oral antilipemic agent which inhibits HMG-CoA reductase. It is used to lower total cholesterol, low density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB), non-high density lipoprotein-cholesterol (non-HDL-C), and trigleride (TG) plasma concentrations while increasing HDL-C concentrations. High LDL-C, low HDL-C and high TG concentrations in the plasma are associated with increased risk of atherosclerosis and cardiovascular disease. The total cholesterol to HDL-C ratio is a strong predictor of coronary artery disease and high ratios are associated with higher risk of disease. Increased levels of HDL-C are associated with lower cardiovascular risk. By decreasing LDL-C and TG and increasing HDL-C, rosuvastatin reduces the risk of cardiovascular morbidity and mortality. Elevated cholesterol levels, and in particular, elevated low-density lipoprotein (LDL) levels, are an important risk factor for the development of CVD. Use of statins to target and reduce LDL levels has been shown in a number of landmark studies to significantly reduce the risk of development of CVD and all-cause mortality. Statins are considered a cost-effective treatment option for CVD due to their evidence of reducing all-cause mortality including fatal and non-fatal CVD as well as the need for surgical revascularization or angioplasty following a heart attack. Evidence has shown that even for low-risk individuals (with <10% risk of a major vascular event occurring within 5 years) statins cause a 20%-22% relative reduction in major cardiovascular events (heart attack, stroke, coronary revascularization, and coronary death) for every 1 mmol/L reduction in LDL without any significant side effects or risks. Skeletal Muscle Effects Simvastatin occasionally causes myopathy manifested as muscle pain, tenderness or weakness with creatine kinase (CK) above ten times the upper limit of normal (ULN). Myopathy sometimes takes the form of rhabdomyolysis with or without acute renal failure secondary to myoglobinuria, and rare fatalities have occurred. Predisposing factors for myopathy include advanced age (≥65 years), female gender, uncontrolled hypothyroidism, and renal impairment. Chinese patients may also be at increased risk for myopathy. In most cases, muscle symptoms and CK increases resolved when treatment was promptly discontinued. In a clinical trial database of 41,413 patients, the incidence of myopathy was approximately 0.03% and 0.08% at 20 and 40 mg/day, respectively, while the risk of myopathy with simvastatin 80 mg (0.61%) was disproportionately higher than that observed at the lower doses. It's therefore recommended that the 80mg dose of simvastatin should be used only in patients who have been taking simvastatin 80 mg chronically (e.g., for 12 months or more) without evidence of muscle toxicity. As well, patients already stabilized on simvastatin 80mg should be monitored closely for evidence of muscle toxicity; if they need to be initiated on an interacting drug that is contraindicated or is associated with a dose cap for simvastatin, that patient should be switched to an alternative statin with less potential for the drug-drug interaction. The risk of myopathy during treatment with simvastatin may be increased with concurrent administration of interacting drugs such as fenofibrate, niacin, gemfibrozil, cyclosporine, and strong inhibitors of the CYP3A4 enzyme. Cases of myopathy, including rhabdomyolysis, have been reported with HMG-CoA reductase inhibitors coadministered with colchicine, and caution should therefore be exercised when prescribing these two medications together. Liver Enzyme Abnormalities Persistent increases (to more than 3X the ULN) in serum transaminases have occurred in approximately 1% of patients who received simvastatin in clinical studies. When drug treatment was interrupted or discontinued in these patients, the transaminase levels usually fell slowly to pretreatment levels. The increases were not associated with jaundice or other clinical signs or symptoms. In the Scandinavian Simvastatin Survival Study (4S), the number of patients with more than one transaminase elevation to >3 times the ULN, over the course of the study, was not significantly different between the simvastatin and placebo groups (14 [0.7%] vs. 12 [0.6%]). The frequency of single elevations of ALT to 3 times the ULN was significantly higher in the simvastatin group in the first year of the study (20 vs. 8, p=0.023), but not thereafter. In the HPS (Heart Protection Study), in which 20,536 patients were randomized to receive simvastatin 40 mg/day or placebo, the incidences of elevated transaminases (>3X ULN confirmed by repeat test) were 0.21% (n=21) for patients treated with simvastatin and 0.09% (n=9) for patients treated with placebo. Endocrine Effects Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including simvastatin. Although cholesterol is the precursor of all steroid hormones, studies with simvastatin have suggested that this agent has no clinical effect on steroidogenesis. Simvastatin caused no increase in biliary lithogenicity and, therefore, would not be expected to increase the incidence of gallstones. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Simvastatin is a prodrug in which the 6-membered lactone ring of simvastatin is hydrolyzed in vivo to generate the beta,delta-dihydroxy acid, an active metabolite structurally similar to HMG-CoA (hydroxymethylglutaryl CoA). Once hydrolyzed, simvastatin competes with HMG-CoA for HMG-CoA reductase, a hepatic microsomal enzyme, which catalyzes the conversion of HMG-CoA to mevalonate, an early rate-limiting step in cholesterol biosynthesis. Simvastatin acts primarily in the liver, where decreased hepatic cholesterol concentrations stimulate the upregulation of hepatic low density lipoprotein (LDL) receptors which increases hepatic uptake of LDL. Simvastatin also inhibits hepatic synthesis of very low density lipoprotein (VLDL). The overall effect is a decrease in plasma LDL and VLDL. At therapeutic doses, the HMG-CoA enzyme is not completely blocked by simvastatin activity, thereby allowing biologically necessary amounts of mevalonate to remain available. As mevalonate is an early step in the biosynthetic pathway for cholesterol, therapy with simvastatin would also not be expected to cause any accumulation of potentially toxic sterols. In addition, HMG-CoA is metabolized readily back to acetyl-CoA, which participates in many biosynthetic processes in the body. In vitro and in vivo animal studies also demonstrate that simvastatin exerts vasculoprotective effects independent of its lipid-lowering properties, also known as the pleiotropic effects of statins. This includes improvement in endothelial function, enhanced stability of atherosclerotic plaques, reduced oxidative stress and inflammation, and inhibition of the thrombogenic response. Statins have also been found to bind allosterically to β2 integrin function-associated antigen-1 (LFA-1), which plays an important role in leukocyte trafficking and in T cell activation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Peak plasma concentrations of both active and total inhibitors were attained within 1.3 to 2.4 hours post-dose. While the recommended therapeutic dose range is 10 to 40 mg/day, there was no substantial deviation from linearity of AUC with an increase in dose to as high as 120 mg. Relative to the fasting state, the plasma profile of inhibitors was not affected when simvastatin was administered immediately before a test meal. In a pharmacokinetic study of 17 healthy Chinese volunteers, the major PK parameters were as follows: Tmax 1.44 hours, Cmax 9.83 ug/L, t1/2 4.85 hours, and AUC 40.32ug·h/L. Simvastatin undergoes extensive first-pass extraction in the liver, the target organ for the inhibition of HMG-CoA reductase and the primary site of action. This tissue selectivity (and consequent low systemic exposure) of orally administered simvastatin has been shown to be far greater than that observed when the drug is administered as the enzymatically active form, i.e. as the open hydroxyacid. In animal studies, after oral dosing, simvastatin achieved substantially higher concentrations in the liver than in non-target tissues. However, because simvastatin undergoes extensive first-pass metabolism, the bioavailability of the drug in the systemic system is low. In a single-dose study in nine healthy subjects, it was estimated that less than 5% of an oral dose of simvastatin reached the general circulation in the form of active inhibitors. Genetic differences in the OATP1B1 (Organic-Anion-Transporting Polypeptide 1B1) hepatic transporter encoded by the SCLCO1B1 gene (Solute Carrier Organic Anion Transporter family member 1B1) have been shown to impact simvastatin pharmacokinetics. Evidence from pharmacogenetic studies of the c.521T>C single nucleotide polymorphism (SNP) showed that simvastatin plasma concentrations were increased on average 3.2-fold for individuals homozygous for 521CC compared to homozygous 521TT individuals. The 521CC genotype is also associated with a marked increase in the risk of developing myopathy, likely secondary to increased systemic exposure. Other statin drugs impacted by this polymorphism include rosuvastatin, pitavastatin, atorvastatin, lovastatin, and pravastatin. For patients known to have the above-mentioned c.521CC OATP1B1 genotype, a maximum daily dose of 20mg of simvastatin is recommended to avoid adverse effects from the increased exposure to the drug, such as muscle pain and risk of rhabdomyolysis. Evidence has also been obtained with other statins such as rosuvastatin that concurrent use of statins and inhibitors of Breast Cancer Resistance Protein (BCRP) such as elbasvir and grazoprevir increased the plasma concentration of these statins. Further evidence is needed, however a dose adjustment of simvastatin may be necessary. Other statin drugs impacted by this polymorphism include fluvastatin and atorvastatin. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Rat studies indicate that when radiolabeled simvastatin was administered, simvastatin-derived radioactivity crossed the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both simvastatin and its β-hydroxyacid metabolite are highly bound (approximately 95%) to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Simvastatin is administered as the inactive lactone derivative that is then metabolically activated to its β-hydroxyacid form by a combination of spontaneous chemical conversion and enzyme-mediated hydrolysis by nonspecific carboxyesterases in the intestinal wall, liver, and plasma. Oxidative metabolism in the liver is primarily mediated by CYP3A4 and CYP3A5, with the remaining metabolism occurring through CYP2C8 and CYP2C9. The major active metabolites of simvastatin are β-hydroxyacid metabolite and its 6'-hydroxy, 6'-hydroxymethyl, and 6'-exomethylene derivatives. Polymorphisms in the CYP3A5 gene have been shown to affect the disposition of simvastatin and may provide a plausible explanation for interindividual variability of simvastatin disposition and pharmacokinetics. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following an oral dose of 14C-labeled simvastatin in man, 13% of the dose was excreted in urine and 60% in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4.85 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cholib, FloLipid, Simcor, Vytorin, Zocor •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Simvastatin Simvastatina Simvastatine Simvastatinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Simvastatin is an HMG-CoA reductase inhibitor used to lower lipid levels and reduce the risk of cardiovascular events including myocardial infarction and stroke.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Simvastatin interact? Information: •Drug A: Abatacept •Drug B: Simvastatin •Severity: MODERATE •Description: The metabolism of Simvastatin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Simvastatin is indicated for the treatment of hyperlipidemia to reduce elevated total cholesterol (total-C), low-density lipoprotein cholesterol (LDL‑C), apolipoprotein B (Apo B), and triglycerides (TG), and to increase high-density lipoprotein cholesterol (HDL-C). This includes the treatment of primary hyperlipidemia (Fredrickson type IIa, heterozygous familial and nonfamilial), mixed dyslipidemia (Fredrickson type IIb), hypertriglyceridemia (Fredrickson type IV hyperlipidemia), primary dysbetalipoproteinemia (Fredrickson type III hyperlipidemia), homozygous familial hypercholesterolemia (HoFH) as an adjunct to other lipid-lowering treatments, as well as adolescent patients with Heterozygous Familial Hypercholesterolemia (HeFH). Simvastatin is also indicated to reduce the risk of cardiovascular morbidity and mortality including myocardial infarction, stroke, and the need for revascularization procedures. It is primarily used in patients at high risk of coronary events because of existing coronary heart disease, diabetes, peripheral vessel disease, history of stroke or other cerebrovascular disease. Prescribing of statin medications is considered standard practice following any cardiovascular events and for people with a moderate to high risk of development of CVD. Statin-indicated conditions include diabetes mellitus, clinical atherosclerosis (including myocardial infarction, acute coronary syndromes, stable angina, documented coronary artery disease, stroke, trans ischemic attack (TIA), documented carotid disease, peripheral artery disease, and claudication), abdominal aortic aneurysm, chronic kidney disease, and severely elevated LDL-C levels. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Simvastatin is an oral antilipemic agent which inhibits HMG-CoA reductase. It is used to lower total cholesterol, low density lipoprotein-cholesterol (LDL-C), apolipoprotein B (apoB), non-high density lipoprotein-cholesterol (non-HDL-C), and trigleride (TG) plasma concentrations while increasing HDL-C concentrations. High LDL-C, low HDL-C and high TG concentrations in the plasma are associated with increased risk of atherosclerosis and cardiovascular disease. The total cholesterol to HDL-C ratio is a strong predictor of coronary artery disease and high ratios are associated with higher risk of disease. Increased levels of HDL-C are associated with lower cardiovascular risk. By decreasing LDL-C and TG and increasing HDL-C, rosuvastatin reduces the risk of cardiovascular morbidity and mortality. Elevated cholesterol levels, and in particular, elevated low-density lipoprotein (LDL) levels, are an important risk factor for the development of CVD. Use of statins to target and reduce LDL levels has been shown in a number of landmark studies to significantly reduce the risk of development of CVD and all-cause mortality. Statins are considered a cost-effective treatment option for CVD due to their evidence of reducing all-cause mortality including fatal and non-fatal CVD as well as the need for surgical revascularization or angioplasty following a heart attack. Evidence has shown that even for low-risk individuals (with <10% risk of a major vascular event occurring within 5 years) statins cause a 20%-22% relative reduction in major cardiovascular events (heart attack, stroke, coronary revascularization, and coronary death) for every 1 mmol/L reduction in LDL without any significant side effects or risks. Skeletal Muscle Effects Simvastatin occasionally causes myopathy manifested as muscle pain, tenderness or weakness with creatine kinase (CK) above ten times the upper limit of normal (ULN). Myopathy sometimes takes the form of rhabdomyolysis with or without acute renal failure secondary to myoglobinuria, and rare fatalities have occurred. Predisposing factors for myopathy include advanced age (≥65 years), female gender, uncontrolled hypothyroidism, and renal impairment. Chinese patients may also be at increased risk for myopathy. In most cases, muscle symptoms and CK increases resolved when treatment was promptly discontinued. In a clinical trial database of 41,413 patients, the incidence of myopathy was approximately 0.03% and 0.08% at 20 and 40 mg/day, respectively, while the risk of myopathy with simvastatin 80 mg (0.61%) was disproportionately higher than that observed at the lower doses. It's therefore recommended that the 80mg dose of simvastatin should be used only in patients who have been taking simvastatin 80 mg chronically (e.g., for 12 months or more) without evidence of muscle toxicity. As well, patients already stabilized on simvastatin 80mg should be monitored closely for evidence of muscle toxicity; if they need to be initiated on an interacting drug that is contraindicated or is associated with a dose cap for simvastatin, that patient should be switched to an alternative statin with less potential for the drug-drug interaction. The risk of myopathy during treatment with simvastatin may be increased with concurrent administration of interacting drugs such as fenofibrate, niacin, gemfibrozil, cyclosporine, and strong inhibitors of the CYP3A4 enzyme. Cases of myopathy, including rhabdomyolysis, have been reported with HMG-CoA reductase inhibitors coadministered with colchicine, and caution should therefore be exercised when prescribing these two medications together. Liver Enzyme Abnormalities Persistent increases (to more than 3X the ULN) in serum transaminases have occurred in approximately 1% of patients who received simvastatin in clinical studies. When drug treatment was interrupted or discontinued in these patients, the transaminase levels usually fell slowly to pretreatment levels. The increases were not associated with jaundice or other clinical signs or symptoms. In the Scandinavian Simvastatin Survival Study (4S), the number of patients with more than one transaminase elevation to >3 times the ULN, over the course of the study, was not significantly different between the simvastatin and placebo groups (14 [0.7%] vs. 12 [0.6%]). The frequency of single elevations of ALT to 3 times the ULN was significantly higher in the simvastatin group in the first year of the study (20 vs. 8, p=0.023), but not thereafter. In the HPS (Heart Protection Study), in which 20,536 patients were randomized to receive simvastatin 40 mg/day or placebo, the incidences of elevated transaminases (>3X ULN confirmed by repeat test) were 0.21% (n=21) for patients treated with simvastatin and 0.09% (n=9) for patients treated with placebo. Endocrine Effects Increases in HbA1c and fasting serum glucose levels have been reported with HMG-CoA reductase inhibitors, including simvastatin. Although cholesterol is the precursor of all steroid hormones, studies with simvastatin have suggested that this agent has no clinical effect on steroidogenesis. Simvastatin caused no increase in biliary lithogenicity and, therefore, would not be expected to increase the incidence of gallstones. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Simvastatin is a prodrug in which the 6-membered lactone ring of simvastatin is hydrolyzed in vivo to generate the beta,delta-dihydroxy acid, an active metabolite structurally similar to HMG-CoA (hydroxymethylglutaryl CoA). Once hydrolyzed, simvastatin competes with HMG-CoA for HMG-CoA reductase, a hepatic microsomal enzyme, which catalyzes the conversion of HMG-CoA to mevalonate, an early rate-limiting step in cholesterol biosynthesis. Simvastatin acts primarily in the liver, where decreased hepatic cholesterol concentrations stimulate the upregulation of hepatic low density lipoprotein (LDL) receptors which increases hepatic uptake of LDL. Simvastatin also inhibits hepatic synthesis of very low density lipoprotein (VLDL). The overall effect is a decrease in plasma LDL and VLDL. At therapeutic doses, the HMG-CoA enzyme is not completely blocked by simvastatin activity, thereby allowing biologically necessary amounts of mevalonate to remain available. As mevalonate is an early step in the biosynthetic pathway for cholesterol, therapy with simvastatin would also not be expected to cause any accumulation of potentially toxic sterols. In addition, HMG-CoA is metabolized readily back to acetyl-CoA, which participates in many biosynthetic processes in the body. In vitro and in vivo animal studies also demonstrate that simvastatin exerts vasculoprotective effects independent of its lipid-lowering properties, also known as the pleiotropic effects of statins. This includes improvement in endothelial function, enhanced stability of atherosclerotic plaques, reduced oxidative stress and inflammation, and inhibition of the thrombogenic response. Statins have also been found to bind allosterically to β2 integrin function-associated antigen-1 (LFA-1), which plays an important role in leukocyte trafficking and in T cell activation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Peak plasma concentrations of both active and total inhibitors were attained within 1.3 to 2.4 hours post-dose. While the recommended therapeutic dose range is 10 to 40 mg/day, there was no substantial deviation from linearity of AUC with an increase in dose to as high as 120 mg. Relative to the fasting state, the plasma profile of inhibitors was not affected when simvastatin was administered immediately before a test meal. In a pharmacokinetic study of 17 healthy Chinese volunteers, the major PK parameters were as follows: Tmax 1.44 hours, Cmax 9.83 ug/L, t1/2 4.85 hours, and AUC 40.32ug·h/L. Simvastatin undergoes extensive first-pass extraction in the liver, the target organ for the inhibition of HMG-CoA reductase and the primary site of action. This tissue selectivity (and consequent low systemic exposure) of orally administered simvastatin has been shown to be far greater than that observed when the drug is administered as the enzymatically active form, i.e. as the open hydroxyacid. In animal studies, after oral dosing, simvastatin achieved substantially higher concentrations in the liver than in non-target tissues. However, because simvastatin undergoes extensive first-pass metabolism, the bioavailability of the drug in the systemic system is low. In a single-dose study in nine healthy subjects, it was estimated that less than 5% of an oral dose of simvastatin reached the general circulation in the form of active inhibitors. Genetic differences in the OATP1B1 (Organic-Anion-Transporting Polypeptide 1B1) hepatic transporter encoded by the SCLCO1B1 gene (Solute Carrier Organic Anion Transporter family member 1B1) have been shown to impact simvastatin pharmacokinetics. Evidence from pharmacogenetic studies of the c.521T>C single nucleotide polymorphism (SNP) showed that simvastatin plasma concentrations were increased on average 3.2-fold for individuals homozygous for 521CC compared to homozygous 521TT individuals. The 521CC genotype is also associated with a marked increase in the risk of developing myopathy, likely secondary to increased systemic exposure. Other statin drugs impacted by this polymorphism include rosuvastatin, pitavastatin, atorvastatin, lovastatin, and pravastatin. For patients known to have the above-mentioned c.521CC OATP1B1 genotype, a maximum daily dose of 20mg of simvastatin is recommended to avoid adverse effects from the increased exposure to the drug, such as muscle pain and risk of rhabdomyolysis. Evidence has also been obtained with other statins such as rosuvastatin that concurrent use of statins and inhibitors of Breast Cancer Resistance Protein (BCRP) such as elbasvir and grazoprevir increased the plasma concentration of these statins. Further evidence is needed, however a dose adjustment of simvastatin may be necessary. Other statin drugs impacted by this polymorphism include fluvastatin and atorvastatin. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Rat studies indicate that when radiolabeled simvastatin was administered, simvastatin-derived radioactivity crossed the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both simvastatin and its β-hydroxyacid metabolite are highly bound (approximately 95%) to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Simvastatin is administered as the inactive lactone derivative that is then metabolically activated to its β-hydroxyacid form by a combination of spontaneous chemical conversion and enzyme-mediated hydrolysis by nonspecific carboxyesterases in the intestinal wall, liver, and plasma. Oxidative metabolism in the liver is primarily mediated by CYP3A4 and CYP3A5, with the remaining metabolism occurring through CYP2C8 and CYP2C9. The major active metabolites of simvastatin are β-hydroxyacid metabolite and its 6'-hydroxy, 6'-hydroxymethyl, and 6'-exomethylene derivatives. Polymorphisms in the CYP3A5 gene have been shown to affect the disposition of simvastatin and may provide a plausible explanation for interindividual variability of simvastatin disposition and pharmacokinetics. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following an oral dose of 14C-labeled simvastatin in man, 13% of the dose was excreted in urine and 60% in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4.85 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cholib, FloLipid, Simcor, Vytorin, Zocor •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Simvastatin Simvastatina Simvastatine Simvastatinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Simvastatin is an HMG-CoA reductase inhibitor used to lower lipid levels and reduce the risk of cardiovascular events including myocardial infarction and stroke. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Siponimod interact?

•Drug A: Abatacept •Drug B: Siponimod •Severity: MAJOR •Description: The metabolism of Siponimod can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): This drug is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Immune system effects Siponimod causes a dose-dependent decrease of the peripheral blood lymphocyte count within 6 hours of the first dose, caused by the reversible accumulation of lymphocytes in lymphoid tissues, due to lack of lymphocyte release. This results in a decrease in the inflammation that is involved in multiple sclerosis. Lymphocyte counts return to normal in 90% of patients within 10 days after the cessation of therapy. Effects on heart rate and rhythm Siponimod causes a temporary decrease in heart rate and atrioventricular conduction upon beginning treatment. The maximum fall in heart rate is observed in the first 6 hours post ingestion. Autonomic heart responses, including diurnal variation of heart rate and response to exercise activities, are not altered by siponimod treatment. Effects on pulmonary function Dose-dependent decreases in absolute forced expiratory volume over a time frame of 1 second were noted in siponimod-treated patients and were higher than in patients taking placebo. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inflammation of the white and gray matter tissues in the central nervous system caused by localized immune cell infiltration and their cytokines are the initial cause of damage in MS. B lymphocytes and their cytokines are other factors in the pathogenesis of MS. Lymphotoxin [or transforming growth factor beta (TGF-β)] and TNF-α produced by these cells encourage inflammation. The S1P receptor is an important receptor related to the function of lymphocytes and can be found in the central nervous system. S1P receptor (S1PR) signaling is associated with a wide variety of physiological processes for lymphocytes, including their egress and recirculation. Siponimod is classified as a sphingosine-1-phosphate (S1P) receptor modulator. Siponimod binds with high affinity to both S1P receptors 1 and 5. This drug blocks the ability of lymphocytes to release from the lymph nodes, decreasing the number of lymphocytes found in the peripheral blood. The mechanism by which siponimod exerts therapeutic effects in multiple sclerosis is not known at this time, but may involve the abovementioned decrease of lymphocytes into the central nervous system, decreasing the inflammatory effects of MS. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time (Tmax) to attain maximum plasma concentrations (Cmax) after oral administration of immediate-release oral doses of siponimod was found to be approximately 4 hours ( with a range 3 - 8 hours). Siponimod is heavily absorbed (at a rate greater than or equal to 70%). The absolute oral bioavailability of siponimod is about 84%. Steady-state concentrations were attained after approximately 6 days of daily administration of a single dose of siponimod. Effects of food on absorption Food ingestion leads to delayed siponimod absorption (the median Tmax increased by approximately 2-3 hours). Food intake has no effect on the systemic exposure of siponimod (Cmax and AUC). Therefore, siponimod may be taken without regard to food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Siponimod distributes to body tissues with an average volume of distribution of 124 L. Siponimod fraction mesaured in plasma is 68% in humans. Animal studies demonstrate that siponimod readily crosses the blood-brain-barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of siponimod is higher than 99.9% in healthy patients as well as hepatic and renal impaired patients. Because of the high plasma protein binding of siponimod, hemodialysis is not likely to change the total and unbound siponimod concentration and no dose adjustments are expected based on this. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Siponimod is extensively metabolized, mainly by CYP2C9 enzyme (79.3%), and subsequently by CYP3A4 enzyme (18.5%). The pharmacological activity of the main metabolites M3 and M17 is not expected to be responsible for the clinical effect and the safety of siponimod in humans. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Siponimod is eliminated from the systemic circulation mainly due to metabolism, and subsequent biliary/fecal excretion. Unchanged siponimod was not detected in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent elimination half-life is approximately 30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent systemic clearance of 3.11 L/h has been estimated in MS patients. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Carcinogenesis Oral carcinogenicity studies of siponimod were performed in mice and rats. There was an increase in malignant lymphoma in females at all doses and in hemangiosarcoma and combined hemangioma and hemangiosarcoma at all doses in males and females. The lowest dose tested is approximately 5 times the recommended human dose (RHD) of 2 mg/day. Mutagenesis Siponimod was negative in several in vitro (Ames, chromosomal aberration in mammalian cells) and in vivo (micronucleus in mouse and rat) assays. Impairment of fertility When siponimod was administered orally (0, 2, 20, or 200 mg/kg) to male rats (mated with untreated females) before and throughout the mating period, there was a dose-related increase in the precoital interval at any dose. A decrease in implantation sites, an increase in preimplantation loss, and a decrease in the number of viable fetuses were noted at the highest dose tested. The higher no-effect dose for adverse effects on fertility (20 mg/kg) is approximately 100 times the recommended human dose. When siponimod was administered orally (0, 0.1, 0.3, or 1 mg/kg) to female rats (mated with untreated males) prior to and during mating, and continuing to Day 6 of gestation, no effects on fertility were noted up to the highest dose studied (1 mg/kg). Plasma siponimod exposure (AUC) at the highest dose studied is about 16 times that in humans at the recommended human dose. Use in pregnancy and lactation Siponimod may cause fetal harm, based on the results of animal studies. Because it takes about 10 days to eliminate this drug from the body, women of childbearing potential should use adequate contraception to avoid pregnancy during and for 10 days after the cessation of treatment. No data currently exist regarding the presence of siponimod in human milk. A study in lactating rats demonstrated excretion of the drug and/or its metabolites in milk. The benefits nursing should be considered as well as the mother’s clinical requirement for this drug and any possible adverse effects on the breastfed infant from siponimod. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mayzent 0.25 Mg Starter Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Siponimod is a medication used to treat relapsing multiple sclerosis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Siponimod interact? Information: •Drug A: Abatacept •Drug B: Siponimod •Severity: MAJOR •Description: The metabolism of Siponimod can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): This drug is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Immune system effects Siponimod causes a dose-dependent decrease of the peripheral blood lymphocyte count within 6 hours of the first dose, caused by the reversible accumulation of lymphocytes in lymphoid tissues, due to lack of lymphocyte release. This results in a decrease in the inflammation that is involved in multiple sclerosis. Lymphocyte counts return to normal in 90% of patients within 10 days after the cessation of therapy. Effects on heart rate and rhythm Siponimod causes a temporary decrease in heart rate and atrioventricular conduction upon beginning treatment. The maximum fall in heart rate is observed in the first 6 hours post ingestion. Autonomic heart responses, including diurnal variation of heart rate and response to exercise activities, are not altered by siponimod treatment. Effects on pulmonary function Dose-dependent decreases in absolute forced expiratory volume over a time frame of 1 second were noted in siponimod-treated patients and were higher than in patients taking placebo. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inflammation of the white and gray matter tissues in the central nervous system caused by localized immune cell infiltration and their cytokines are the initial cause of damage in MS. B lymphocytes and their cytokines are other factors in the pathogenesis of MS. Lymphotoxin [or transforming growth factor beta (TGF-β)] and TNF-α produced by these cells encourage inflammation. The S1P receptor is an important receptor related to the function of lymphocytes and can be found in the central nervous system. S1P receptor (S1PR) signaling is associated with a wide variety of physiological processes for lymphocytes, including their egress and recirculation. Siponimod is classified as a sphingosine-1-phosphate (S1P) receptor modulator. Siponimod binds with high affinity to both S1P receptors 1 and 5. This drug blocks the ability of lymphocytes to release from the lymph nodes, decreasing the number of lymphocytes found in the peripheral blood. The mechanism by which siponimod exerts therapeutic effects in multiple sclerosis is not known at this time, but may involve the abovementioned decrease of lymphocytes into the central nervous system, decreasing the inflammatory effects of MS. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time (Tmax) to attain maximum plasma concentrations (Cmax) after oral administration of immediate-release oral doses of siponimod was found to be approximately 4 hours ( with a range 3 - 8 hours). Siponimod is heavily absorbed (at a rate greater than or equal to 70%). The absolute oral bioavailability of siponimod is about 84%. Steady-state concentrations were attained after approximately 6 days of daily administration of a single dose of siponimod. Effects of food on absorption Food ingestion leads to delayed siponimod absorption (the median Tmax increased by approximately 2-3 hours). Food intake has no effect on the systemic exposure of siponimod (Cmax and AUC). Therefore, siponimod may be taken without regard to food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Siponimod distributes to body tissues with an average volume of distribution of 124 L. Siponimod fraction mesaured in plasma is 68% in humans. Animal studies demonstrate that siponimod readily crosses the blood-brain-barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of siponimod is higher than 99.9% in healthy patients as well as hepatic and renal impaired patients. Because of the high plasma protein binding of siponimod, hemodialysis is not likely to change the total and unbound siponimod concentration and no dose adjustments are expected based on this. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Siponimod is extensively metabolized, mainly by CYP2C9 enzyme (79.3%), and subsequently by CYP3A4 enzyme (18.5%). The pharmacological activity of the main metabolites M3 and M17 is not expected to be responsible for the clinical effect and the safety of siponimod in humans. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Siponimod is eliminated from the systemic circulation mainly due to metabolism, and subsequent biliary/fecal excretion. Unchanged siponimod was not detected in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The apparent elimination half-life is approximately 30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent systemic clearance of 3.11 L/h has been estimated in MS patients. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Carcinogenesis Oral carcinogenicity studies of siponimod were performed in mice and rats. There was an increase in malignant lymphoma in females at all doses and in hemangiosarcoma and combined hemangioma and hemangiosarcoma at all doses in males and females. The lowest dose tested is approximately 5 times the recommended human dose (RHD) of 2 mg/day. Mutagenesis Siponimod was negative in several in vitro (Ames, chromosomal aberration in mammalian cells) and in vivo (micronucleus in mouse and rat) assays. Impairment of fertility When siponimod was administered orally (0, 2, 20, or 200 mg/kg) to male rats (mated with untreated females) before and throughout the mating period, there was a dose-related increase in the precoital interval at any dose. A decrease in implantation sites, an increase in preimplantation loss, and a decrease in the number of viable fetuses were noted at the highest dose tested. The higher no-effect dose for adverse effects on fertility (20 mg/kg) is approximately 100 times the recommended human dose. When siponimod was administered orally (0, 0.1, 0.3, or 1 mg/kg) to female rats (mated with untreated males) prior to and during mating, and continuing to Day 6 of gestation, no effects on fertility were noted up to the highest dose studied (1 mg/kg). Plasma siponimod exposure (AUC) at the highest dose studied is about 16 times that in humans at the recommended human dose. Use in pregnancy and lactation Siponimod may cause fetal harm, based on the results of animal studies. Because it takes about 10 days to eliminate this drug from the body, women of childbearing potential should use adequate contraception to avoid pregnancy during and for 10 days after the cessation of treatment. No data currently exist regarding the presence of siponimod in human milk. A study in lactating rats demonstrated excretion of the drug and/or its metabolites in milk. The benefits nursing should be considered as well as the mother’s clinical requirement for this drug and any possible adverse effects on the breastfed infant from siponimod. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mayzent 0.25 Mg Starter Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Siponimod is a medication used to treat relapsing multiple sclerosis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Sipuleucel-T interact?

•Drug A: Abatacept •Drug B: Sipuleucel-T •Severity: MODERATE •Description: The therapeutic efficacy of Sipuleucel-T can be decreased when used in combination with Abatacept. •Extended Description: The concurrent use of chemotherapy or immunosuppressive agents (such as systemic corticosteroids) given with the leukapheresis procedure of Sipuleucel-T has not been evaluated. Immunosuppressive agents may decrease the efficacy of Sipuleucel-T, which is an immunotherapeutic drug (enhancing immunity). This is due to the opposing effect of immunosuppressive and immunotherapeutic drugs. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

The concurrent use of chemotherapy or immunosuppressive agents (such as systemic corticosteroids) given with the leukapheresis procedure of Sipuleucel-T has not been evaluated. Immunosuppressive agents may decrease the efficacy of Sipuleucel-T, which is an immunotherapeutic drug (enhancing immunity). This is due to the opposing effect of immunosuppressive and immunotherapeutic drugs. The severity of the interaction is moderate.

Question: Does Abatacept and Sipuleucel-T interact? Information: •Drug A: Abatacept •Drug B: Sipuleucel-T •Severity: MODERATE •Description: The therapeutic efficacy of Sipuleucel-T can be decreased when used in combination with Abatacept. •Extended Description: The concurrent use of chemotherapy or immunosuppressive agents (such as systemic corticosteroids) given with the leukapheresis procedure of Sipuleucel-T has not been evaluated. Immunosuppressive agents may decrease the efficacy of Sipuleucel-T, which is an immunotherapeutic drug (enhancing immunity). This is due to the opposing effect of immunosuppressive and immunotherapeutic drugs. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: The concurrent use of chemotherapy or immunosuppressive agents (such as systemic corticosteroids) given with the leukapheresis procedure of Sipuleucel-T has not been evaluated. Immunosuppressive agents may decrease the efficacy of Sipuleucel-T, which is an immunotherapeutic drug (enhancing immunity). This is due to the opposing effect of immunosuppressive and immunotherapeutic drugs. The severity of the interaction is moderate.

Does Abatacept and Sirolimus interact?

•Drug A: Abatacept •Drug B: Sirolimus •Severity: MAJOR •Description: The metabolism of Sirolimus can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sirolimus is indicated for the prophylaxis of organ rejection in patients aged 13 years or older receiving renal transplants. In patients at low-to moderate-immunologic risk, it is recommended that sirolimus be used initially in a regimen with cyclosporine and corticosteroids; cyclosporine should be withdrawn two to four months after transplantation. In patients at high-immunologic risk (defined as Black recipients and/or repeat renal transplant recipients who lost a previous allograft for immunologic reason and/or patients with high panel-reactive antibodies [PRA; peak PRA level > 80%]), it is recommended that sirolimus be used in combination with cyclosporine and corticosteroids for the first year following transplantation. It is also used to treat lymphangioleiomyomatosis. In the US, albumin-bound sirolimus for intravenous injection is indicated for the treatment of adult patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumour (PEComa). In Europe, it is recommended that sirolimus for the prophylaxis of organ rejection in renal transplants is used in combination with cyclosporin microemulsion and corticosteroids for two to three months. Sirolimus may be continued as maintenance therapy with corticosteroids only if cyclosporin microemulsion can be progressively discontinued. Topical sirolimus is indicated for the treatment of facial angiofibroma associated with tuberous sclerosis in adults and pediatric patients six years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sirolimus is an immunosuppressant drug with antifungal and antitumour effects. In animal models, sirolimus prolonged allograft survival following various organ transplants and reversed an acute rejection of heart and kidney allografts in rats. Upon oral administration of 2 mg/day and 5 mg/day, sirolimus significantly reduced the incidence of organ rejection in low- to moderate-immunologic risk renal transplant patients at six months following transplantation compared with either azathioprine or placebo. In some studies, the immunosuppressive effect of sirolimus lasted up to six months after discontinuation of therapy: this tolerization effect is alloantigen-specific. Sirolimus potently inhibits antigen-induced proliferation of T cells, B cells, and antibody production. In rodent models of autoimmune disease, sirolimus suppressed immune-mediated events associated with systemic lupus erythematosus, collagen-induced arthritis, autoimmune type I diabetes, autoimmune myocarditis, experimental allergic encephalomyelitis, graft-versus-host disease, and autoimmune uveoretinitis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sirolimus works by inhibiting T-lymphocyte activation and proliferation stimulated by antigens and cytokines such as interleukin (IL)-2, IL-4, and IL-15. In target cells, sirolimus binds to the cytoplasmic receptor FK506-binding protein-12 (FKBP12), an immunophilin, to form an immunosuppressive complex. FKBP12-sirolimus complex binds to and inhibits the activation of the mammalian target of rapamycin (mTOR), which is a serine/threonine-specific protein kinase that regulates cell growth, proliferation, survival, mobility, and angiogenesis. mTOR regulates the downstream signalling pathways involved in cell survival, such as the phosphatidylinositol-3 kinase (PI3K)/Akt signalling pathway. Inhibition of mTOR leads to the suppression of cytokine-driven T-cell proliferation, thus the progression from the G1 to the S phase of the cell cycle is inhibited. Sirolimus also inhibits antibody production. In vitro, sirolimus and other mTOR inhibitors inhibit the production of certain growth factors that may affect angiogenesis, fibroblast proliferation, and vascular permeability. Lymphangioleiomyomatosis is a disorder that primarily affects the lungs. It is characterized by lung tissue infiltration, unregulated alveolar smooth muscle proliferation, and cystic destruction of parenchyma. Although infrequent, it occurs as a symptomatic pulmonary complication in tuberous sclerosis complex (TSC), which is an inherited disorder caused by mutations in TSC genes. Loss of functional TSC gene leads to the aberrant activation of the mTOR signalling pathway, resulting in cellular proliferation and release of lymphangiogenic growth factors. Sirolimus inhibits the activated mTOR pathway and proliferation of alveolar smooth muscle cell proliferation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In adult renal transplant patients with low- to moderate-immunologic risk, oral administration of 2 mg sirolimus led to a C max of 14.4 ± 5.3 ng/mL for oral solution and 15.0 ± 4.9 ng/mL for oral tablets. The t max was 2.1 ± 0.8 hours for oral solution and 3.5 ± 2.4 hours for oral tablets. In healthy subjects, the t max is one hour. In a multi-dose study, steady-state was reached six days following repeated twice-daily administration without an initial loading dose, with the average trough concentration of sirolimus increased approximately 2- to 3-fold. It is suspected that a loading dose of three times the maintenance dose will provide near steady-state concentrations within one day in most patients. The systemic availability of sirolimus is approximately 14%. In healthy subjects, the mean bioavailability of sirolimus after administration of the tablet is approximately 27% higher relative to the solution. Sirolimus tablets are not bioequivalent to the solution; however, clinical equivalence has been demonstrated at the 2 mg dose level. Sirolimus concentrations, following the administration of Rapamune Oral Solution to stable renal transplant patients, are dose-proportional between 3 and 12 mg/m. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (± SD) blood-to-plasma ratio of sirolimus was 36 ± 18 L in stable renal allograft patients, indicating that sirolimus is extensively partitioned into formed blood elements. The mean volume of distribution (V ss/F ) of sirolimus is 12 ± 8 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sirolimus is 92% bound to human plasma proteins, mainly serum albumin (97%), α1-acid glycoprotein, and lipoproteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sirolimus undergoes extensive metabolism in the intestinal wall and liver. Sirolimus is primarily metabolized by O-demethylation and/or hydroxylation via CYP3A4 to form seven major metabolites, including hydroxy, demethyl, and hydroxydemethyl metabolites, which are pharmacologically inactive. Sirolimus also undergoes counter-transport from enterocytes of the small intestine into the gut lumen. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of [ C] sirolimus in healthy subjects, about 91% of the radioactivity was recovered from feces and only 2.2% of the radioactivity was detected in urine. Some of the metabolites of sirolimus are also detectable in feces and urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean ± SD terminal elimination half-life (t½) of sirolimus after multiple dosing in stable renal transplant patients was estimated to be about 62 ± 16 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In adult renal transplant patients with low- to moderate-immunologic risk, oral administration of 2 mg sirolimus led to oral clearance of 173 ± 50 mL/h/kg for oral solution and 139 ± 63 mL/h/kg for oral tablets. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 of sirolimus is 800 mg/kg in rats and 2500 mg/kg in mouse. Sirolimus is a narrow therapeutic index drug. Although there are reports of overdose with sirolimus, there is limited information on overdose in the clinical setting. Symptoms of overdose are consistent with the adverse effects of sirolimus. General supportive measures are recommended in the event of an overdose. Because sirolimus has low aqueous solubility and high erythrocyte and plasma protein binding, it is not expected to be dialyzable to any significant extent. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Fyarro, Hyftor, Rapamune •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rapamycin Sirolimús Sirolimus Sirolimusum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sirolimus is an mTOR inhibitor immunosuppressant used to prevent organ transplant rejections, treat lymphangioleiomyomatosis, and treat adults with perivascular epithelioid cell tumors.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Sirolimus interact? Information: •Drug A: Abatacept •Drug B: Sirolimus •Severity: MAJOR •Description: The metabolism of Sirolimus can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sirolimus is indicated for the prophylaxis of organ rejection in patients aged 13 years or older receiving renal transplants. In patients at low-to moderate-immunologic risk, it is recommended that sirolimus be used initially in a regimen with cyclosporine and corticosteroids; cyclosporine should be withdrawn two to four months after transplantation. In patients at high-immunologic risk (defined as Black recipients and/or repeat renal transplant recipients who lost a previous allograft for immunologic reason and/or patients with high panel-reactive antibodies [PRA; peak PRA level > 80%]), it is recommended that sirolimus be used in combination with cyclosporine and corticosteroids for the first year following transplantation. It is also used to treat lymphangioleiomyomatosis. In the US, albumin-bound sirolimus for intravenous injection is indicated for the treatment of adult patients with locally advanced unresectable or metastatic malignant perivascular epithelioid cell tumour (PEComa). In Europe, it is recommended that sirolimus for the prophylaxis of organ rejection in renal transplants is used in combination with cyclosporin microemulsion and corticosteroids for two to three months. Sirolimus may be continued as maintenance therapy with corticosteroids only if cyclosporin microemulsion can be progressively discontinued. Topical sirolimus is indicated for the treatment of facial angiofibroma associated with tuberous sclerosis in adults and pediatric patients six years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sirolimus is an immunosuppressant drug with antifungal and antitumour effects. In animal models, sirolimus prolonged allograft survival following various organ transplants and reversed an acute rejection of heart and kidney allografts in rats. Upon oral administration of 2 mg/day and 5 mg/day, sirolimus significantly reduced the incidence of organ rejection in low- to moderate-immunologic risk renal transplant patients at six months following transplantation compared with either azathioprine or placebo. In some studies, the immunosuppressive effect of sirolimus lasted up to six months after discontinuation of therapy: this tolerization effect is alloantigen-specific. Sirolimus potently inhibits antigen-induced proliferation of T cells, B cells, and antibody production. In rodent models of autoimmune disease, sirolimus suppressed immune-mediated events associated with systemic lupus erythematosus, collagen-induced arthritis, autoimmune type I diabetes, autoimmune myocarditis, experimental allergic encephalomyelitis, graft-versus-host disease, and autoimmune uveoretinitis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sirolimus works by inhibiting T-lymphocyte activation and proliferation stimulated by antigens and cytokines such as interleukin (IL)-2, IL-4, and IL-15. In target cells, sirolimus binds to the cytoplasmic receptor FK506-binding protein-12 (FKBP12), an immunophilin, to form an immunosuppressive complex. FKBP12-sirolimus complex binds to and inhibits the activation of the mammalian target of rapamycin (mTOR), which is a serine/threonine-specific protein kinase that regulates cell growth, proliferation, survival, mobility, and angiogenesis. mTOR regulates the downstream signalling pathways involved in cell survival, such as the phosphatidylinositol-3 kinase (PI3K)/Akt signalling pathway. Inhibition of mTOR leads to the suppression of cytokine-driven T-cell proliferation, thus the progression from the G1 to the S phase of the cell cycle is inhibited. Sirolimus also inhibits antibody production. In vitro, sirolimus and other mTOR inhibitors inhibit the production of certain growth factors that may affect angiogenesis, fibroblast proliferation, and vascular permeability. Lymphangioleiomyomatosis is a disorder that primarily affects the lungs. It is characterized by lung tissue infiltration, unregulated alveolar smooth muscle proliferation, and cystic destruction of parenchyma. Although infrequent, it occurs as a symptomatic pulmonary complication in tuberous sclerosis complex (TSC), which is an inherited disorder caused by mutations in TSC genes. Loss of functional TSC gene leads to the aberrant activation of the mTOR signalling pathway, resulting in cellular proliferation and release of lymphangiogenic growth factors. Sirolimus inhibits the activated mTOR pathway and proliferation of alveolar smooth muscle cell proliferation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In adult renal transplant patients with low- to moderate-immunologic risk, oral administration of 2 mg sirolimus led to a C max of 14.4 ± 5.3 ng/mL for oral solution and 15.0 ± 4.9 ng/mL for oral tablets. The t max was 2.1 ± 0.8 hours for oral solution and 3.5 ± 2.4 hours for oral tablets. In healthy subjects, the t max is one hour. In a multi-dose study, steady-state was reached six days following repeated twice-daily administration without an initial loading dose, with the average trough concentration of sirolimus increased approximately 2- to 3-fold. It is suspected that a loading dose of three times the maintenance dose will provide near steady-state concentrations within one day in most patients. The systemic availability of sirolimus is approximately 14%. In healthy subjects, the mean bioavailability of sirolimus after administration of the tablet is approximately 27% higher relative to the solution. Sirolimus tablets are not bioequivalent to the solution; however, clinical equivalence has been demonstrated at the 2 mg dose level. Sirolimus concentrations, following the administration of Rapamune Oral Solution to stable renal transplant patients, are dose-proportional between 3 and 12 mg/m. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean (± SD) blood-to-plasma ratio of sirolimus was 36 ± 18 L in stable renal allograft patients, indicating that sirolimus is extensively partitioned into formed blood elements. The mean volume of distribution (V ss/F ) of sirolimus is 12 ± 8 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sirolimus is 92% bound to human plasma proteins, mainly serum albumin (97%), α1-acid glycoprotein, and lipoproteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sirolimus undergoes extensive metabolism in the intestinal wall and liver. Sirolimus is primarily metabolized by O-demethylation and/or hydroxylation via CYP3A4 to form seven major metabolites, including hydroxy, demethyl, and hydroxydemethyl metabolites, which are pharmacologically inactive. Sirolimus also undergoes counter-transport from enterocytes of the small intestine into the gut lumen. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of [ C] sirolimus in healthy subjects, about 91% of the radioactivity was recovered from feces and only 2.2% of the radioactivity was detected in urine. Some of the metabolites of sirolimus are also detectable in feces and urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean ± SD terminal elimination half-life (t½) of sirolimus after multiple dosing in stable renal transplant patients was estimated to be about 62 ± 16 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In adult renal transplant patients with low- to moderate-immunologic risk, oral administration of 2 mg sirolimus led to oral clearance of 173 ± 50 mL/h/kg for oral solution and 139 ± 63 mL/h/kg for oral tablets. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 of sirolimus is 800 mg/kg in rats and 2500 mg/kg in mouse. Sirolimus is a narrow therapeutic index drug. Although there are reports of overdose with sirolimus, there is limited information on overdose in the clinical setting. Symptoms of overdose are consistent with the adverse effects of sirolimus. General supportive measures are recommended in the event of an overdose. Because sirolimus has low aqueous solubility and high erythrocyte and plasma protein binding, it is not expected to be dialyzable to any significant extent. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Fyarro, Hyftor, Rapamune •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Rapamycin Sirolimús Sirolimus Sirolimusum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sirolimus is an mTOR inhibitor immunosuppressant used to prevent organ transplant rejections, treat lymphangioleiomyomatosis, and treat adults with perivascular epithelioid cell tumors. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Sitagliptin interact?

•Drug A: Abatacept •Drug B: Sitagliptin •Severity: MODERATE •Description: The metabolism of Sitagliptin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sitagliptin is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It is not used to treat type 1 diabetes or patients with a history of pancreatitis. It is also used in combination with metformin or ertugliflozin. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sitagliptin inhibits DPP-4 which leads to increased levels of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide(GIP), decreased levels of glucagon, and a stronger insulin response to glucose. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inhibition of DPP-4 by sitagliptin slows DPP-4 mediated inactivation of incretins like GLP-1 and GIP. Incretins are released throughout the day and upregulated in response to meals as part of glucose homeostasis. Reduced inhibition of incretins increase insulin synthesis and decrease glucagon release in a manner dependant on glucose concentrations. These effects lead to an overall increase in blood glucose control which is demonstrated by reduced glycosylated hemoglobin (HbA1c). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sitagliptin is 87% orally bioavailable and taking it with or without food does not affect its pharmacokinetics. Sitagliptin reaches maximum plasma concentration in 2 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 198L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 38%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sitagliptin is mostly not metabolised, with 79% of the dose excreted in the urine as the unchanged parent compound. Minor metabolic pathways are mediated mainly by cytochrome p450(CYP)3A4 and to a lesser extent by CYP2C8. After 18 hours, 81% of the dose has remained unchanged, while 2% has been N-sulfated to the M1 metabolite, 6% has been oxidatively desaturated and cyclized to the M2 metabolite, <1% glucuronidated at an unknown site to the M3 metabolite, <1% has been carbamoylated and glucuronidated to the M4 metabolite, 6% has been oxidatively saturated and cyclized to the M5 metabolite, and 2% has been hydroxylated at an unknown site to the M6 metabolite. The M2 metabolite is the cis isomer while the M5 metabolite is the trans isomer of the same metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 79% of sitagliptin is excreted in the urine as the unchanged parent compound. 87% of the dose is eliminated in the urine and 13% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 12.4 hours. Other studies have reported a half life of approximately 11 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 350mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Animal studies in pregnancy have shown no adverse effects on the mother or offspring at normal doses, however these results are not always applicable to humans. There is a voluntary fetal exposure registry. Animal studies at 100 times the maximum recommended human dose resulted in an increase in rib malformations. Sitagliptin is excreted in the milk of rats but it is not known if it would also be expressed in human breast milk. Because many drugs are expressed in human breast milk, the risk and benefit of prescribing the medication must be considered. There is currently a lack of safety and effectiveness data in pediatric patients. No differences in safety and efficacy were observed in geriatric patients compared to younger patients, however caution should be used in this population as they are more likely to have reduced renal function. Sitagliptin has also been associated with a 34% relative risk increase for all cause infection. There was no significant difference in patient response across sex, age, race, ethnicity, and BMI. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Janumet, Januvia, Ristaben, Steglujan, Tesavel, Velmetia, Xelevia, Zituvimet, Zituvio •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sitagliptin is an oral dipeptidyl peptidase-4 (DPP-4) inhibitor used for the management of type 2 diabetes mellitus.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sitagliptin interact? Information: •Drug A: Abatacept •Drug B: Sitagliptin •Severity: MODERATE •Description: The metabolism of Sitagliptin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sitagliptin is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It is not used to treat type 1 diabetes or patients with a history of pancreatitis. It is also used in combination with metformin or ertugliflozin. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sitagliptin inhibits DPP-4 which leads to increased levels of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide(GIP), decreased levels of glucagon, and a stronger insulin response to glucose. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Inhibition of DPP-4 by sitagliptin slows DPP-4 mediated inactivation of incretins like GLP-1 and GIP. Incretins are released throughout the day and upregulated in response to meals as part of glucose homeostasis. Reduced inhibition of incretins increase insulin synthesis and decrease glucagon release in a manner dependant on glucose concentrations. These effects lead to an overall increase in blood glucose control which is demonstrated by reduced glycosylated hemoglobin (HbA1c). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sitagliptin is 87% orally bioavailable and taking it with or without food does not affect its pharmacokinetics. Sitagliptin reaches maximum plasma concentration in 2 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 198L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 38%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sitagliptin is mostly not metabolised, with 79% of the dose excreted in the urine as the unchanged parent compound. Minor metabolic pathways are mediated mainly by cytochrome p450(CYP)3A4 and to a lesser extent by CYP2C8. After 18 hours, 81% of the dose has remained unchanged, while 2% has been N-sulfated to the M1 metabolite, 6% has been oxidatively desaturated and cyclized to the M2 metabolite, <1% glucuronidated at an unknown site to the M3 metabolite, <1% has been carbamoylated and glucuronidated to the M4 metabolite, 6% has been oxidatively saturated and cyclized to the M5 metabolite, and 2% has been hydroxylated at an unknown site to the M6 metabolite. The M2 metabolite is the cis isomer while the M5 metabolite is the trans isomer of the same metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 79% of sitagliptin is excreted in the urine as the unchanged parent compound. 87% of the dose is eliminated in the urine and 13% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 12.4 hours. Other studies have reported a half life of approximately 11 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 350mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Animal studies in pregnancy have shown no adverse effects on the mother or offspring at normal doses, however these results are not always applicable to humans. There is a voluntary fetal exposure registry. Animal studies at 100 times the maximum recommended human dose resulted in an increase in rib malformations. Sitagliptin is excreted in the milk of rats but it is not known if it would also be expressed in human breast milk. Because many drugs are expressed in human breast milk, the risk and benefit of prescribing the medication must be considered. There is currently a lack of safety and effectiveness data in pediatric patients. No differences in safety and efficacy were observed in geriatric patients compared to younger patients, however caution should be used in this population as they are more likely to have reduced renal function. Sitagliptin has also been associated with a 34% relative risk increase for all cause infection. There was no significant difference in patient response across sex, age, race, ethnicity, and BMI. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Janumet, Januvia, Ristaben, Steglujan, Tesavel, Velmetia, Xelevia, Zituvimet, Zituvio •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sitagliptin is an oral dipeptidyl peptidase-4 (DPP-4) inhibitor used for the management of type 2 diabetes mellitus. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Smallpox (Vaccinia) Vaccine, Live interact?

•Drug A: Abatacept •Drug B: Smallpox (Vaccinia) Vaccine, Live •Severity: MODERATE •Description: The therapeutic efficacy of Smallpox (Vaccinia) Vaccine, Live can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Smallpox (Vaccinia) Vaccine, Live interact? Information: •Drug A: Abatacept •Drug B: Smallpox (Vaccinia) Vaccine, Live •Severity: MODERATE •Description: The therapeutic efficacy of Smallpox (Vaccinia) Vaccine, Live can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Solifenacin interact?

•Drug A: Abatacept •Drug B: Solifenacin •Severity: MODERATE •Description: The metabolism of Solifenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Solifenacin tablets are indicated to treat an overactive bladder with urinary incontinence, urgency, and frequency. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Solifenacin antagonizes the M2 and M3 muscarinic receptors in the bladder to treat an overactive bladder. It has a long duration of action as it is usually taken once daily. Patients taking solifenacin should be aware of the risks of angioedema and anaphylaxis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Solifenacin is a competitive muscarinic receptor antagonist. It has the highest affinity for M3, M1, and M2 muscarinic receptors. 80% of the muscarinic receptors in the bladder are M2, while 20% are M3. Solifenacin's antagonism of the M3 receptor prevents contraction of the detrusor muscle, while antagonism of the M2 receptor may prevent contraction of smooth muscle in the bladder. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Solifenacin is well absorbed in the duodenum, jejunum, and ileum but not the stomach. Absorption occurs via passive diffusion and so no transporters are involved. The mean oral bioavailability of solifenacin is 88%. The T max of solifenacin is 3-8 hours with a C ss of 32.3ng/mL for a 5mg oral dose and 62.9ng/mL for a 10mg oral dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of solifenacin is 600L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Solifenacin is 93-96% protein bound in plasma, mainly to alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Solifenacin undergoes N-oxidation at the quinuclidin ring by cytochrome P450, though the exact enzymes are not revealed in the literature. The tetrahydroisoquinolone ring is 4R-hydroxylated by CYP3A4, CYP1A1, and CYP2D6. A 4R-hydroxy N-oxide metabolite is also formed by CYP3A4. Finally, solifenacin can undergo direct glucuronidation. Only solifenacin and the 4R-hydroxy metabolite are pharmacologically active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 69.2±7.8% of a radiolabelled dose is recovered in the urine, 22.5±3.3% was recovered in feces, and 0.4±7.8% was recovered in exhaled air. 18% of solifenacin is eliminated as the N-oxide metabolite, 9% is eliminated as the 4R-hydroxy N-oxide metabolite, and 8% is eliminated as the 4R-hydroxy metabolite. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life of solifenacin ranges from 33-85 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of solifenacin is 7-14L/h and a renal clearance of 0.67-1.51L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD 50 of Solifenacin has yet to be determined. Signs of overdose include severe anticholinergic effects, mental status changes, and decreased consciousness. In case of overdose, treat patients with gastric lavage and supportive measures. Monitor patients with an ECG. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vesicare •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Solifenacin is a muscarinic antagonist with antispasmodic properties used to treat urge urinary incontinence, urgency, and urinary frequency associated with an overactive bladder.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Solifenacin interact? Information: •Drug A: Abatacept •Drug B: Solifenacin •Severity: MODERATE •Description: The metabolism of Solifenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Solifenacin tablets are indicated to treat an overactive bladder with urinary incontinence, urgency, and frequency. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Solifenacin antagonizes the M2 and M3 muscarinic receptors in the bladder to treat an overactive bladder. It has a long duration of action as it is usually taken once daily. Patients taking solifenacin should be aware of the risks of angioedema and anaphylaxis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Solifenacin is a competitive muscarinic receptor antagonist. It has the highest affinity for M3, M1, and M2 muscarinic receptors. 80% of the muscarinic receptors in the bladder are M2, while 20% are M3. Solifenacin's antagonism of the M3 receptor prevents contraction of the detrusor muscle, while antagonism of the M2 receptor may prevent contraction of smooth muscle in the bladder. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Solifenacin is well absorbed in the duodenum, jejunum, and ileum but not the stomach. Absorption occurs via passive diffusion and so no transporters are involved. The mean oral bioavailability of solifenacin is 88%. The T max of solifenacin is 3-8 hours with a C ss of 32.3ng/mL for a 5mg oral dose and 62.9ng/mL for a 10mg oral dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of solifenacin is 600L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Solifenacin is 93-96% protein bound in plasma, mainly to alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Solifenacin undergoes N-oxidation at the quinuclidin ring by cytochrome P450, though the exact enzymes are not revealed in the literature. The tetrahydroisoquinolone ring is 4R-hydroxylated by CYP3A4, CYP1A1, and CYP2D6. A 4R-hydroxy N-oxide metabolite is also formed by CYP3A4. Finally, solifenacin can undergo direct glucuronidation. Only solifenacin and the 4R-hydroxy metabolite are pharmacologically active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 69.2±7.8% of a radiolabelled dose is recovered in the urine, 22.5±3.3% was recovered in feces, and 0.4±7.8% was recovered in exhaled air. 18% of solifenacin is eliminated as the N-oxide metabolite, 9% is eliminated as the 4R-hydroxy N-oxide metabolite, and 8% is eliminated as the 4R-hydroxy metabolite. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life of solifenacin ranges from 33-85 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of solifenacin is 7-14L/h and a renal clearance of 0.67-1.51L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD 50 of Solifenacin has yet to be determined. Signs of overdose include severe anticholinergic effects, mental status changes, and decreased consciousness. In case of overdose, treat patients with gastric lavage and supportive measures. Monitor patients with an ECG. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vesicare •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Solifenacin is a muscarinic antagonist with antispasmodic properties used to treat urge urinary incontinence, urgency, and urinary frequency associated with an overactive bladder. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Sonidegib interact?

•Drug A: Abatacept •Drug B: Sonidegib •Severity: MAJOR •Description: The metabolism of Sonidegib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sonidegib is approved for use in the US and EU for treatment of adults with locally advanced basal cell carcinoma (BCC) that has recurred post surgery or radiation therapy. It is also approved for adult patients with BCC who are not eligible for surgery or radiation therapy. (2) •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sonidegib has been shown to inhibit a transmembrane protein called SMO which plays a role in Hh signal transduction. This has resulted in inhibition of Hh signaling as well as antitumour activity in various animal models. In a transgenic mouse model of islet cell neoplasms, tumour volume was reduce by 95% in mice treated with sonidegib when compared with untreated mice. (2) •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The hedgehog pathway is involved in many human cancers. Sonidegib effectively inhibits the regulator called smoothened (Smo), preventing the hedgehog pathway from functioning. As a result, tumours that depend on the hedgehog pathway are unable to grow. (1) •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sonidegib is rapidly absorbed in the fasted state with peak concentrations occurring 2-4 hours after administration. (2) However, the total absorption of Sonidegib is low (roughly 6-7%). (1) •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Estimated volume of distribution = 9166 L (2) •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sonidegib is over 97% bound to plasma proteins, and binding is independent of concentration. (2) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sonidegib is primarily metabolized via oxidation and amide hydrolysis. (1) The enzyme responsible for the majority of metabolism is the cytochrome P450 (CYP) 3A4 enzyme. (2) •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Around 70% of Sonidegib is eliminated in the feces, while 30% is eliminated in the urine. (2) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Half-life ~ 28 days (2) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse events occurred more frequently with higher doses, 800 mg once daily when compared to a lower dose of 200 mg once daily. In the 200 mg group, frequent adverse events (occurring in ≥2% of patients) included: elevated creatine phosphokinase (6%), increased lipase (5%), muscle spasms (3%), asthenia (3%), and hypertension (3%). In the 800 mg group, frequent adverse events included: elevated creatine phosphokinase (13%), increased lipase (5%), weight loss (5%), muscle spasms (5%), decreased appetite (4%), rhabdomyolysis (3%), nausea (3%), hypertension (3%), increased alanine aminotransferase (3%), increased aspartate aminotransferase (3%), fatigue (2%), syncope (2%), anaemia (2%), dehydration (2%), hyperkalaemia (2%) and myalgia (2%). Rhabdomyolysis cases reported by investigators were not confirmed by the adjudication committee on muscle toxicity or the independent safety review. (2) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Odomzo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Erismodegib Sonidegib •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sonidegib is an antineoplastic agent used for the treatment of locally advanced recurrent basal cell carcinoma (BCC) following surgery and radiation therapy, or in cases where surgery or radiation therapy are not appropriate.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Sonidegib interact? Information: •Drug A: Abatacept •Drug B: Sonidegib •Severity: MAJOR •Description: The metabolism of Sonidegib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sonidegib is approved for use in the US and EU for treatment of adults with locally advanced basal cell carcinoma (BCC) that has recurred post surgery or radiation therapy. It is also approved for adult patients with BCC who are not eligible for surgery or radiation therapy. (2) •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sonidegib has been shown to inhibit a transmembrane protein called SMO which plays a role in Hh signal transduction. This has resulted in inhibition of Hh signaling as well as antitumour activity in various animal models. In a transgenic mouse model of islet cell neoplasms, tumour volume was reduce by 95% in mice treated with sonidegib when compared with untreated mice. (2) •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The hedgehog pathway is involved in many human cancers. Sonidegib effectively inhibits the regulator called smoothened (Smo), preventing the hedgehog pathway from functioning. As a result, tumours that depend on the hedgehog pathway are unable to grow. (1) •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sonidegib is rapidly absorbed in the fasted state with peak concentrations occurring 2-4 hours after administration. (2) However, the total absorption of Sonidegib is low (roughly 6-7%). (1) •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Estimated volume of distribution = 9166 L (2) •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sonidegib is over 97% bound to plasma proteins, and binding is independent of concentration. (2) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sonidegib is primarily metabolized via oxidation and amide hydrolysis. (1) The enzyme responsible for the majority of metabolism is the cytochrome P450 (CYP) 3A4 enzyme. (2) •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Around 70% of Sonidegib is eliminated in the feces, while 30% is eliminated in the urine. (2) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Half-life ~ 28 days (2) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse events occurred more frequently with higher doses, 800 mg once daily when compared to a lower dose of 200 mg once daily. In the 200 mg group, frequent adverse events (occurring in ≥2% of patients) included: elevated creatine phosphokinase (6%), increased lipase (5%), muscle spasms (3%), asthenia (3%), and hypertension (3%). In the 800 mg group, frequent adverse events included: elevated creatine phosphokinase (13%), increased lipase (5%), weight loss (5%), muscle spasms (5%), decreased appetite (4%), rhabdomyolysis (3%), nausea (3%), hypertension (3%), increased alanine aminotransferase (3%), increased aspartate aminotransferase (3%), fatigue (2%), syncope (2%), anaemia (2%), dehydration (2%), hyperkalaemia (2%) and myalgia (2%). Rhabdomyolysis cases reported by investigators were not confirmed by the adjudication committee on muscle toxicity or the independent safety review. (2) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Odomzo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Erismodegib Sonidegib •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sonidegib is an antineoplastic agent used for the treatment of locally advanced recurrent basal cell carcinoma (BCC) following surgery and radiation therapy, or in cases where surgery or radiation therapy are not appropriate. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Sorafenib interact?

•Drug A: Abatacept •Drug B: Sorafenib •Severity: MAJOR •Description: The metabolism of Sorafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sorafenib is indicated for the treatment of unresectable hepatocellular carcinoma and advanced renal cell carcinoma. In the US, it is also indicated for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma that is refractory to radioactive iodine treatment. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sorafenib decreases tumour cell proliferation in vitro. It attenuated tumour growth of human tumour xenografts in immunocompromised mice, reduced tumour angiogenesis, and increased tumour apoptosis in models of hepatocellular carcinoma, renal cell carcinoma, and differentiated thyroid carcinoma. Some studies suggest that sorafenib induces apoptosis in several tumour cell lines, although this effect is inconsistent across cell lines. Antiviral effects of sorafenib have been documented, as it was shown to inhibit hepatitis C viral replication in vitro. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Kinases are involved in tumour cell signalling, proliferation, angiogenesis, and apoptosis. Sorafenib inhibits multiple intracellular serine/threonine kinases in the Ras/mitogen-activated protein kinase (MAPK) signal transduction pathway. Intracellular Raf serine/threonine kinase isoforms inhibited by sorafenib include Raf-1 (or C-Raf), wild-type B-Raf, and mutant B-Raf. Sorafenib inhibits cell surface tyrosine kinase receptors such as KIT, FMS-like tyrosine kinase 3 (FLT-3), RET, RET/PTC, vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, VEGFR-3, and platelet-derived growth factor receptor-β (PDGFR-β). Sorafenib is thought to exhibit a dual mechanism of action: it blocks tumour proliferation and growth by inhibiting the RAF/MEK/extracellular signal-regulated kinase (ERK) pathway on tumour cells, and reduces tumour angiogenesis by inhibiting VEGFR and PDGFR signalling in tumour vasculature. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The administration of multiple doses for seven days resulted in a 2.5- to 7-fold accumulation compared to a single dose. Steady-state concentrations were achieved within seven days, with a peak-to-trough ratio of mean concentrations of less than 2. Mean C max and AUC increased less than proportionally beyond oral doses of 400 mg administered twice daily. The T max is approximately three hours. The mean relative bioavailability was 38–49% following the administration of oral sorafenib tablets. A high-fat meal reduced bioavailability by 29%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Sorafenib is widely distributed to tissues, indicating that it is lipophilic. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, sorafenib is 99.5% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sorafenib undergoes oxidative metabolism by CYP3A4 in the liver, as well as glucuronidation by UGT1A9 in the liver and kidneys. At steady-state, sorafenib accounts for 70-85% of the circulating analytes in plasma. About eight metabolites of sorafenib have been identified, of which five were detected in plasma. The main circulating metabolite was the pyridine N-oxide form, which comprises approximately 9–16% of the total circulating dose at steady-state: the pharmacological activity of this metabolite was comparable to the parent drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a 100 mg dose of sorafenib, about 96% of the dose was recovered within 14 days, with 77% of the dose being excreted in feces and 19% of the dose being excreted in urine as glucuronidated metabolites. Unchanged sorafenib accounted for 51% of the dose excreted in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of sorafenib was approximately 25 to 48 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral lowest published toxic dose (Toxic Dose Low, TDLo) is 2.84 mg/kg/21D (intermittent). The oral LD 50 of sorafenib tosylate in rats is >2000 mg/kg. The adverse reactions observed at 800 mg sorafenib twice daily (twice the recommended dose) were primarily diarrhea and dermatologic. No information is available on symptoms of acute overdose in animals because of the saturation of absorption in oral acute toxicity studies conducted in animals. The prescribing information recommends the discontinuation of sorafenib treatment and initiation of supportive care in cases of suspected overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nexavar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sorafenib Sorafénib Sorafenibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sorafenib is a kinase inhibitor used to treat unresectable liver carcinoma, advanced renal carcinoma, and differentiated thyroid carcinoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Sorafenib interact? Information: •Drug A: Abatacept •Drug B: Sorafenib •Severity: MAJOR •Description: The metabolism of Sorafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sorafenib is indicated for the treatment of unresectable hepatocellular carcinoma and advanced renal cell carcinoma. In the US, it is also indicated for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma that is refractory to radioactive iodine treatment. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sorafenib decreases tumour cell proliferation in vitro. It attenuated tumour growth of human tumour xenografts in immunocompromised mice, reduced tumour angiogenesis, and increased tumour apoptosis in models of hepatocellular carcinoma, renal cell carcinoma, and differentiated thyroid carcinoma. Some studies suggest that sorafenib induces apoptosis in several tumour cell lines, although this effect is inconsistent across cell lines. Antiviral effects of sorafenib have been documented, as it was shown to inhibit hepatitis C viral replication in vitro. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Kinases are involved in tumour cell signalling, proliferation, angiogenesis, and apoptosis. Sorafenib inhibits multiple intracellular serine/threonine kinases in the Ras/mitogen-activated protein kinase (MAPK) signal transduction pathway. Intracellular Raf serine/threonine kinase isoforms inhibited by sorafenib include Raf-1 (or C-Raf), wild-type B-Raf, and mutant B-Raf. Sorafenib inhibits cell surface tyrosine kinase receptors such as KIT, FMS-like tyrosine kinase 3 (FLT-3), RET, RET/PTC, vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, VEGFR-3, and platelet-derived growth factor receptor-β (PDGFR-β). Sorafenib is thought to exhibit a dual mechanism of action: it blocks tumour proliferation and growth by inhibiting the RAF/MEK/extracellular signal-regulated kinase (ERK) pathway on tumour cells, and reduces tumour angiogenesis by inhibiting VEGFR and PDGFR signalling in tumour vasculature. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The administration of multiple doses for seven days resulted in a 2.5- to 7-fold accumulation compared to a single dose. Steady-state concentrations were achieved within seven days, with a peak-to-trough ratio of mean concentrations of less than 2. Mean C max and AUC increased less than proportionally beyond oral doses of 400 mg administered twice daily. The T max is approximately three hours. The mean relative bioavailability was 38–49% following the administration of oral sorafenib tablets. A high-fat meal reduced bioavailability by 29%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Sorafenib is widely distributed to tissues, indicating that it is lipophilic. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, sorafenib is 99.5% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sorafenib undergoes oxidative metabolism by CYP3A4 in the liver, as well as glucuronidation by UGT1A9 in the liver and kidneys. At steady-state, sorafenib accounts for 70-85% of the circulating analytes in plasma. About eight metabolites of sorafenib have been identified, of which five were detected in plasma. The main circulating metabolite was the pyridine N-oxide form, which comprises approximately 9–16% of the total circulating dose at steady-state: the pharmacological activity of this metabolite was comparable to the parent drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a 100 mg dose of sorafenib, about 96% of the dose was recovered within 14 days, with 77% of the dose being excreted in feces and 19% of the dose being excreted in urine as glucuronidated metabolites. Unchanged sorafenib accounted for 51% of the dose excreted in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of sorafenib was approximately 25 to 48 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral lowest published toxic dose (Toxic Dose Low, TDLo) is 2.84 mg/kg/21D (intermittent). The oral LD 50 of sorafenib tosylate in rats is >2000 mg/kg. The adverse reactions observed at 800 mg sorafenib twice daily (twice the recommended dose) were primarily diarrhea and dermatologic. No information is available on symptoms of acute overdose in animals because of the saturation of absorption in oral acute toxicity studies conducted in animals. The prescribing information recommends the discontinuation of sorafenib treatment and initiation of supportive care in cases of suspected overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nexavar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sorafenib Sorafénib Sorafenibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sorafenib is a kinase inhibitor used to treat unresectable liver carcinoma, advanced renal carcinoma, and differentiated thyroid carcinoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Sotalol interact?

•Drug A: Abatacept •Drug B: Sotalol •Severity: MAJOR •Description: The metabolism of Sotalol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sotalol is indicated to treat life threatening ventricular arrhytmias and maintain normal sinus rhythm in patients with atrial fibrillation or flutter. There are also oral solutions and intravenous injections indicated for patients requiring sotalol, but for whom a tablet would not be appropriate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sotalol is a competitive inhibitor of the rapid potassium channel. This inhibition lengthens the duration of action potentials and the refractory period in the atria and ventricles. The inhibition of rapid potassium channels is increases as heart rate decreases, which is why adverse effects like torsades de points is more likely to be seen at lower heart rates. L-sotalol also has beta adrenergic receptor blocking activity seen above plasma concentrations of 800ng/L. The beta blocking ability of sotalol further prolongs action potentials. D-sotalol does not have beta blocking activity but also reduces a patient's heart rate while standing or exercising. These actions combine to produce a negative inotropic effect that reduces the strength of contractility of muscle cells in the heart. Extension of the QT interval is also adversely associated with the induction of arrhythmia in patients. Hyperglycemia is a greater risk for non insulin dependant diabetics than insulin dependant diabetics. Beta blockers inhibit insulin secretion which may cause hyperglycemia in type II diabetes mellitus. The risk of hypoglycemia is higher in insulin dependant diabetes than non insulin dependant diabetics. Beta blockers decrease secretion of insulin, which may mask hypoglycemia in an insulin dependant patient. Beta blockers also increase glucose uptake into cells which may prolong or potentiate hypoglycemia. Further information regarding adverse reactions can be found here. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sotalol inhibits beta-1 adrenoceptors in the myocardium as well as rapid potassium channels to slow repolarization, lengthen the QT interval, and slow and shorten conduction of action potentials through the atria. The action of sotalol on beta adrenergic receptors lengthens the sinus node cycle, conduction time through the atrioventricular node, refractory period, and duration of action potentials. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sotalol is 90-100% bioavailable. When taken with a meal, adsorption is lowered by 18%. In patients with a creatinine clearance >80mL/min, the maximum concentration is 6.25±2.19. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution is 1.2-2.4L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 0%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sotalol is not metabolized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 80-90% of a given dose is excreted in the urine as unchanged sotalol. A small fraction of the doses is excreted in the feces as unchanged sotalol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half life is 10-20 hours in healthy patients. In patients with a creatinine clearance >80mL/min, the half life is 17.5±0.97h. In patients with a creatinine clearance 30-80mL/min, the half life is 22.7±6.4h. In patients with a creatinine clearance 10-30mL/min, the half life is 64±27.2h. In patients with a creatinine clearance <10mL/min, the half life is 97.9±57.3h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with a creatinine clearance >80mL/min, the plasma clearance is 6.78±2.72L/h and the renal clearance is 4.99±1.43L/h. In patients with a creatinine clearance 30-80mL/min, the plasma clearance is 2.74±0.53L/h and the renal clearance is 2.00±0.67L/h. In patients with a creatinine clearance 10-30mL/min, the plasma clearance is 1.56±0.44L/h and the renal clearance is 0.65±0.31L/h. In patients with a creatinine clearance <10mL/min, the plasma clearance is 0.65±0.20L/h and the renal clearance is 0.27±0.13L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia. Larger intentional overdoses may present as hypotension, bradycardia, cardiac asystole, prolonged QT interval, torsade de pointes, ventricular tachycardia, and premature ventricular complexes. Stop administering sotalol and observe the patient until the QT interval returns to normal and the heart rate rises above 50 beats per minute. Hemodialysis may help lower plasma concentrations of sotalol as it is not bound to plasma proteins. Bradycardia and cardiac asystole may be treated with atropine, other anticholinergic drugs, beta adrenergic agonists, or transvenous cardiac pacing.. Second or third degree heart block may be treated with a transvenous cardiac pacemaker. Hypotension may be treated with epinephrine or norepinephrine. Bronchospasm may be treated with aminophylline or a beta-2 agonist, possibly at higher than normal doses. Torsade de pointes may be treated with DC cardioversion, transvenous cardiac pacing, epinephrine, or magnesium sulfate. The oral LD50 for rats is 3450mg/kg, intraperitoneal LD50 for rats is 680mg/kg, oral LD50 for mice is 2600mg/kg, and intraperitoneal LD50 for mice is 670mg/kg. Pregnant rabbits given 6 times the maximum recommended human dose showed an increase in fetal death and maternal toxicity, while rats given 18 times the maximum recommended human dose had an increased number of fetal resorptions. Sotalol is present in human breast milk so patients taking sotalol should not breast feed. Sotalol has not been found to be carcinogenic. No studies have been performed regarding mutagenicity or clastogenicity. In animal studies, sotalol was not associated with a reduction in fertility aside from smaller litter sizes. Further information regarding adverse reactions can be found here. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Betapace, Sorine, Sotylize •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sotalol Sotalolo Sotalolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sotalol is a methane sulfonanilide beta adrenergic antagonist used to treat life-threatening ventricular arrhythmias and to maintain sinus rhythm in atrial fibrillation or flutter.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Sotalol interact? Information: •Drug A: Abatacept •Drug B: Sotalol •Severity: MAJOR •Description: The metabolism of Sotalol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sotalol is indicated to treat life threatening ventricular arrhytmias and maintain normal sinus rhythm in patients with atrial fibrillation or flutter. There are also oral solutions and intravenous injections indicated for patients requiring sotalol, but for whom a tablet would not be appropriate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sotalol is a competitive inhibitor of the rapid potassium channel. This inhibition lengthens the duration of action potentials and the refractory period in the atria and ventricles. The inhibition of rapid potassium channels is increases as heart rate decreases, which is why adverse effects like torsades de points is more likely to be seen at lower heart rates. L-sotalol also has beta adrenergic receptor blocking activity seen above plasma concentrations of 800ng/L. The beta blocking ability of sotalol further prolongs action potentials. D-sotalol does not have beta blocking activity but also reduces a patient's heart rate while standing or exercising. These actions combine to produce a negative inotropic effect that reduces the strength of contractility of muscle cells in the heart. Extension of the QT interval is also adversely associated with the induction of arrhythmia in patients. Hyperglycemia is a greater risk for non insulin dependant diabetics than insulin dependant diabetics. Beta blockers inhibit insulin secretion which may cause hyperglycemia in type II diabetes mellitus. The risk of hypoglycemia is higher in insulin dependant diabetes than non insulin dependant diabetics. Beta blockers decrease secretion of insulin, which may mask hypoglycemia in an insulin dependant patient. Beta blockers also increase glucose uptake into cells which may prolong or potentiate hypoglycemia. Further information regarding adverse reactions can be found here. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sotalol inhibits beta-1 adrenoceptors in the myocardium as well as rapid potassium channels to slow repolarization, lengthen the QT interval, and slow and shorten conduction of action potentials through the atria. The action of sotalol on beta adrenergic receptors lengthens the sinus node cycle, conduction time through the atrioventricular node, refractory period, and duration of action potentials. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Sotalol is 90-100% bioavailable. When taken with a meal, adsorption is lowered by 18%. In patients with a creatinine clearance >80mL/min, the maximum concentration is 6.25±2.19. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution is 1.2-2.4L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 0%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sotalol is not metabolized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 80-90% of a given dose is excreted in the urine as unchanged sotalol. A small fraction of the doses is excreted in the feces as unchanged sotalol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half life is 10-20 hours in healthy patients. In patients with a creatinine clearance >80mL/min, the half life is 17.5±0.97h. In patients with a creatinine clearance 30-80mL/min, the half life is 22.7±6.4h. In patients with a creatinine clearance 10-30mL/min, the half life is 64±27.2h. In patients with a creatinine clearance <10mL/min, the half life is 97.9±57.3h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with a creatinine clearance >80mL/min, the plasma clearance is 6.78±2.72L/h and the renal clearance is 4.99±1.43L/h. In patients with a creatinine clearance 30-80mL/min, the plasma clearance is 2.74±0.53L/h and the renal clearance is 2.00±0.67L/h. In patients with a creatinine clearance 10-30mL/min, the plasma clearance is 1.56±0.44L/h and the renal clearance is 0.65±0.31L/h. In patients with a creatinine clearance <10mL/min, the plasma clearance is 0.65±0.20L/h and the renal clearance is 0.27±0.13L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia. Larger intentional overdoses may present as hypotension, bradycardia, cardiac asystole, prolonged QT interval, torsade de pointes, ventricular tachycardia, and premature ventricular complexes. Stop administering sotalol and observe the patient until the QT interval returns to normal and the heart rate rises above 50 beats per minute. Hemodialysis may help lower plasma concentrations of sotalol as it is not bound to plasma proteins. Bradycardia and cardiac asystole may be treated with atropine, other anticholinergic drugs, beta adrenergic agonists, or transvenous cardiac pacing.. Second or third degree heart block may be treated with a transvenous cardiac pacemaker. Hypotension may be treated with epinephrine or norepinephrine. Bronchospasm may be treated with aminophylline or a beta-2 agonist, possibly at higher than normal doses. Torsade de pointes may be treated with DC cardioversion, transvenous cardiac pacing, epinephrine, or magnesium sulfate. The oral LD50 for rats is 3450mg/kg, intraperitoneal LD50 for rats is 680mg/kg, oral LD50 for mice is 2600mg/kg, and intraperitoneal LD50 for mice is 670mg/kg. Pregnant rabbits given 6 times the maximum recommended human dose showed an increase in fetal death and maternal toxicity, while rats given 18 times the maximum recommended human dose had an increased number of fetal resorptions. Sotalol is present in human breast milk so patients taking sotalol should not breast feed. Sotalol has not been found to be carcinogenic. No studies have been performed regarding mutagenicity or clastogenicity. In animal studies, sotalol was not associated with a reduction in fertility aside from smaller litter sizes. Further information regarding adverse reactions can be found here. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Betapace, Sorine, Sotylize •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sotalol Sotalolo Sotalolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sotalol is a methane sulfonanilide beta adrenergic antagonist used to treat life-threatening ventricular arrhythmias and to maintain sinus rhythm in atrial fibrillation or flutter. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Spesolimab interact?

•Drug A: Abatacept •Drug B: Spesolimab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Spesolimab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Spesolimab is indicated for the treatment of generalized pustular psoriasis (GPP) in adults and pediatric patients 12 years of age and older and weighing at least 40 kg. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Spesolimab works to reduce inflammation in GPP in a rapid and sustained manner by blocking inflammatory pathways. In clinical trials, spesolimab reduced pustules and improved other disease measures in patients with GPP, irrespective of IL36RN gene mutation status. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Pustular psoriasis is a type of psoriasis, a chronic and recurrent immune-mediated multisystem disorder. Based on the characteristics and distribution of pustules, the disorder has different phenotypes, such as GPP. While the pathophysiology of psoriasis is not fully understood, some pro-inflammatory cytokines involved in innate and adaptive immune systems have been implicated as key mediators of psoriatic disease. Interleukin (IL)-36 is one of those cytokines whereby unregulated activation and expression of IL-36 - often due to IL36RN gene mutations - can result in pathological autoinflammatory responses in pustular psoriasis. IL-36 is expressed in epithelial and immune cells and has three members, IL-36α, IL-36β, and IL-36γ, that bind to a receptor complex to activate pro-inflammatory and pro-fibrotic downstream signalling pathways, such as increased expression and actions of pro-inflammatory cells and factors. The heterodimeric receptor complex IL-36R comprises an IL-1RL2 subunit - to which IL-36 binds - and an IL-1RAcP co-receptor. The exact mechanism of action of spesolimab in managing psoriatic flares is unclear; however, it is believed to ameliorate inflammation by inhibiting IL-36 signalling. Spesolimab binds to the IL-36R receptor complex, preventing the binding of IL-36 downstream activation of receptor signalling pathways. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A population pharmacokinetic model was developed based on data collected from healthy subjects, patients with GPP, and patients with other diseases. After a single intravenous dose of 900 mg of spesolimab, the population PK model-estimated AUC 0-∞ (95% CI) and C max (95% CI) in a typical anti-drug antibody (ADA)-negative patient with GPP were 4750 (4510, 4970) mcg x day/mL and 238 (218, 256) mcg/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on the population pharmacokinetic analysis, the typical total volume of distribution at steady state was 6.4 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is no information available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolic pathway of spesolimab-sbzo has not been characterized. As a humanized IgG1 monoclonal antibody, spesolimab-sbzo is expected to be degraded into small peptides and amino acids via catabolic pathways in a manner similar to endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): There is no information available. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is 25.5 (24.4, 26.3) days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In the linear dose range (0.3 to 20 mg/kg), based on the population PK model, spesolimab-sbzo clearance (95% CI) in a typical GPP patient without anti-drug antibodies, weighing 70 kg was 0.184 (0.175, 0.194) L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information available regarding the LD 50, acute toxicity profile, and overdose of spesolimab. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Spevigo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Spesolimab is an interleukin-36 receptor antagonist used to treat generalized pustular psoriasis flares in adults.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Spesolimab interact? Information: •Drug A: Abatacept •Drug B: Spesolimab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Spesolimab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Spesolimab is indicated for the treatment of generalized pustular psoriasis (GPP) in adults and pediatric patients 12 years of age and older and weighing at least 40 kg. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Spesolimab works to reduce inflammation in GPP in a rapid and sustained manner by blocking inflammatory pathways. In clinical trials, spesolimab reduced pustules and improved other disease measures in patients with GPP, irrespective of IL36RN gene mutation status. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Pustular psoriasis is a type of psoriasis, a chronic and recurrent immune-mediated multisystem disorder. Based on the characteristics and distribution of pustules, the disorder has different phenotypes, such as GPP. While the pathophysiology of psoriasis is not fully understood, some pro-inflammatory cytokines involved in innate and adaptive immune systems have been implicated as key mediators of psoriatic disease. Interleukin (IL)-36 is one of those cytokines whereby unregulated activation and expression of IL-36 - often due to IL36RN gene mutations - can result in pathological autoinflammatory responses in pustular psoriasis. IL-36 is expressed in epithelial and immune cells and has three members, IL-36α, IL-36β, and IL-36γ, that bind to a receptor complex to activate pro-inflammatory and pro-fibrotic downstream signalling pathways, such as increased expression and actions of pro-inflammatory cells and factors. The heterodimeric receptor complex IL-36R comprises an IL-1RL2 subunit - to which IL-36 binds - and an IL-1RAcP co-receptor. The exact mechanism of action of spesolimab in managing psoriatic flares is unclear; however, it is believed to ameliorate inflammation by inhibiting IL-36 signalling. Spesolimab binds to the IL-36R receptor complex, preventing the binding of IL-36 downstream activation of receptor signalling pathways. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A population pharmacokinetic model was developed based on data collected from healthy subjects, patients with GPP, and patients with other diseases. After a single intravenous dose of 900 mg of spesolimab, the population PK model-estimated AUC 0-∞ (95% CI) and C max (95% CI) in a typical anti-drug antibody (ADA)-negative patient with GPP were 4750 (4510, 4970) mcg x day/mL and 238 (218, 256) mcg/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Based on the population pharmacokinetic analysis, the typical total volume of distribution at steady state was 6.4 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): There is no information available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolic pathway of spesolimab-sbzo has not been characterized. As a humanized IgG1 monoclonal antibody, spesolimab-sbzo is expected to be degraded into small peptides and amino acids via catabolic pathways in a manner similar to endogenous IgG. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): There is no information available. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is 25.5 (24.4, 26.3) days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In the linear dose range (0.3 to 20 mg/kg), based on the population PK model, spesolimab-sbzo clearance (95% CI) in a typical GPP patient without anti-drug antibodies, weighing 70 kg was 0.184 (0.175, 0.194) L/day. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no information available regarding the LD 50, acute toxicity profile, and overdose of spesolimab. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Spevigo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Spesolimab is an interleukin-36 receptor antagonist used to treat generalized pustular psoriasis flares in adults. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and St. John's Wort interact?

•Drug A: Abatacept •Drug B: St. John's Wort •Severity: MODERATE •Description: The metabolism of St. John's Wort can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and St. John's Wort interact? Information: •Drug A: Abatacept •Drug B: St. John's Wort •Severity: MODERATE •Description: The metabolism of St. John's Wort can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Stiripentol interact?

•Drug A: Abatacept •Drug B: Stiripentol •Severity: MODERATE •Description: The metabolism of Stiripentol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In the US, stiripentol is indicated for the treatment of seizures associated with Dravet syndrome in patients taking clobazam who are 6 months of age and older and weighing 7 kg or more. There are no clinical data to support the use of stiripentol as monotherapy in Dravet syndrome. In Europe and Canada, stiripentol is indicated for use as adjunctive therapy with clobazam and valproate to refractory generalized tonic-clonic seizures in patients with Dravet syndrome in infancy whose seizures are not adequately controlled with clobazam and valproate alone. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Stiripentol is an antiepileptic agent that works to reduce seizure frequency. It demonstrates anticonvulsant properties when administered alone and may potentiate GABAergic inhibition via several proposed mechanisms. It provides a therapeutic advantage in improving the efficacy of other antiepileptic drugs by inhibiting cytochrome P450 enzymes that normally metabolize those drugs. The anticonvulsant activity of stiripentol is age-dependent, with increased efficacy in younger patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism by which stiripentol exerts its anticonvulsant effect in humans has not been fully elucidated. Possible mechanisms of action include direct effects mediated through the gamma-aminobutyric acid GABA A receptor and indirect effects involving inhibition of cytochrome P450 activity with a resulting increase in blood levels of clobazam and its active metabolite. Stiripentol is a positive allosteric modulator of GABA A receptors in the brain that enhances the opening duration of the channel by binding to a site different than the benzodiazepine binding site. It binds to GABA A receptors containing any of the α, β, γ, or δ-subunits but displays the most potent potency when bound to receptors containing α3 or δ subunits. Stiripentol also binds to GABA A receptor-dependent chloride channels via a barbiturate-like mechanism. Stiripentol potentiates GABA transmission by enhancing the release of GABA, reducing synaptosomal uptake of GABA, and inhibiting GABA transaminase-mediated breakdown of GABA. Stiripentol is an inhibitor of lactate dehydrogenase (LDH), which is involved in the energy metabolism of neurons and regulation of neuronal excitation. The drug binds to the site separate from the enzyme's lactate and pyruvate binding sites, thereby inhibiting both pyruvate-to-lactate conversion and lactate-to-pyruvate conversion. By inhibiting LDH, stiripentol may induce hyperpolarization, thereby reducing neuronal excitability. LDH inhibitors, including stiripentol, mimic a ketogenic diet, where the energy source in the brain is switched from glucose to mainly ketone bodies. The ketone bodies directly regulate neuronal excitation and seizures via ATP-sensitive potassium channels and vesicular glutamate transporters. Stiripentol is also suggested to exhibit neuroprotective properties, which may reduce injury caused by oxygen-glucose deprivation and glutamate excess. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, stiripentol is quickly and readily absorbed with a median T max of two to three hours. The systemic exposure increases dose-proportionally. Stiripentol has a low bioavailability due to water insolubility and extensive metabolism. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The average volume of distribution is 1.03 L/kg but does not display a dose-dependent relationship. Following administration, stiripentol enters the brain and accumulates in the cerebellum and medulla. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of stiripentol is 99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Stiripentol is extensively metabolized. About 13 different metabolites have been found in urine. The main metabolic processes are demethylenation (oxidative cleavage of the methylenedioxy ring system) and glucuronidation, although precise identification of the enzymes involved has not yet been achieved. Other metabolic pathways include O-methylation of catechol metabolites, hydroxylation of the t-butyl group, and conversion of the allylic alcohol side-chain to the isomeric 3-pentanone structure. In vitro studies suggested that the phase I metabolism of stiripentol is catalyzed by CYP1A2, CYP2C19 and CYP3A4 and possibly other enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Stiripentol is mainly eliminated via metabolism. Its metabolites are excreted mainly via the kidney. Urinary metabolites of stiripentol accounted collectively for the majority (73%) of an oral acute dose whereas a further 13-24% was recovered in feces as unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life is approximately ranges from 4.5 to 13 hours, in a dose-dependent manner. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance decreases markedly at high doses; it falls from approximately 40 L/kg/day at the dose of 600 mg/day to about 8 L/kg/day at the dose of 2,400 mg. Clearance is decreased after repeated administration of stiripentol, probably due to inhibition of the cytochrome P450 isoenzymes responsible for its metabolism. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 in rats is >3 g/kg. There is limited clinical data on stiripentol overdose in humans. In mice, high doses of stiripentol (600 to 1800 mg/kg i.p.) caused decreased motor activity and respiration. Overdose should be managed with supportive and symptomatic treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diacomit •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Estiripentol Stiripentol Stiripentolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Stiripentol is an antiepileptic agent used in combination with other anticonvulsants to treat seizures associated with Dravet syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Stiripentol interact? Information: •Drug A: Abatacept •Drug B: Stiripentol •Severity: MODERATE •Description: The metabolism of Stiripentol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In the US, stiripentol is indicated for the treatment of seizures associated with Dravet syndrome in patients taking clobazam who are 6 months of age and older and weighing 7 kg or more. There are no clinical data to support the use of stiripentol as monotherapy in Dravet syndrome. In Europe and Canada, stiripentol is indicated for use as adjunctive therapy with clobazam and valproate to refractory generalized tonic-clonic seizures in patients with Dravet syndrome in infancy whose seizures are not adequately controlled with clobazam and valproate alone. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Stiripentol is an antiepileptic agent that works to reduce seizure frequency. It demonstrates anticonvulsant properties when administered alone and may potentiate GABAergic inhibition via several proposed mechanisms. It provides a therapeutic advantage in improving the efficacy of other antiepileptic drugs by inhibiting cytochrome P450 enzymes that normally metabolize those drugs. The anticonvulsant activity of stiripentol is age-dependent, with increased efficacy in younger patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism by which stiripentol exerts its anticonvulsant effect in humans has not been fully elucidated. Possible mechanisms of action include direct effects mediated through the gamma-aminobutyric acid GABA A receptor and indirect effects involving inhibition of cytochrome P450 activity with a resulting increase in blood levels of clobazam and its active metabolite. Stiripentol is a positive allosteric modulator of GABA A receptors in the brain that enhances the opening duration of the channel by binding to a site different than the benzodiazepine binding site. It binds to GABA A receptors containing any of the α, β, γ, or δ-subunits but displays the most potent potency when bound to receptors containing α3 or δ subunits. Stiripentol also binds to GABA A receptor-dependent chloride channels via a barbiturate-like mechanism. Stiripentol potentiates GABA transmission by enhancing the release of GABA, reducing synaptosomal uptake of GABA, and inhibiting GABA transaminase-mediated breakdown of GABA. Stiripentol is an inhibitor of lactate dehydrogenase (LDH), which is involved in the energy metabolism of neurons and regulation of neuronal excitation. The drug binds to the site separate from the enzyme's lactate and pyruvate binding sites, thereby inhibiting both pyruvate-to-lactate conversion and lactate-to-pyruvate conversion. By inhibiting LDH, stiripentol may induce hyperpolarization, thereby reducing neuronal excitability. LDH inhibitors, including stiripentol, mimic a ketogenic diet, where the energy source in the brain is switched from glucose to mainly ketone bodies. The ketone bodies directly regulate neuronal excitation and seizures via ATP-sensitive potassium channels and vesicular glutamate transporters. Stiripentol is also suggested to exhibit neuroprotective properties, which may reduce injury caused by oxygen-glucose deprivation and glutamate excess. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, stiripentol is quickly and readily absorbed with a median T max of two to three hours. The systemic exposure increases dose-proportionally. Stiripentol has a low bioavailability due to water insolubility and extensive metabolism. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The average volume of distribution is 1.03 L/kg but does not display a dose-dependent relationship. Following administration, stiripentol enters the brain and accumulates in the cerebellum and medulla. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of stiripentol is 99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Stiripentol is extensively metabolized. About 13 different metabolites have been found in urine. The main metabolic processes are demethylenation (oxidative cleavage of the methylenedioxy ring system) and glucuronidation, although precise identification of the enzymes involved has not yet been achieved. Other metabolic pathways include O-methylation of catechol metabolites, hydroxylation of the t-butyl group, and conversion of the allylic alcohol side-chain to the isomeric 3-pentanone structure. In vitro studies suggested that the phase I metabolism of stiripentol is catalyzed by CYP1A2, CYP2C19 and CYP3A4 and possibly other enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Stiripentol is mainly eliminated via metabolism. Its metabolites are excreted mainly via the kidney. Urinary metabolites of stiripentol accounted collectively for the majority (73%) of an oral acute dose whereas a further 13-24% was recovered in feces as unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life is approximately ranges from 4.5 to 13 hours, in a dose-dependent manner. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance decreases markedly at high doses; it falls from approximately 40 L/kg/day at the dose of 600 mg/day to about 8 L/kg/day at the dose of 2,400 mg. Clearance is decreased after repeated administration of stiripentol, probably due to inhibition of the cytochrome P450 isoenzymes responsible for its metabolism. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 in rats is >3 g/kg. There is limited clinical data on stiripentol overdose in humans. In mice, high doses of stiripentol (600 to 1800 mg/kg i.p.) caused decreased motor activity and respiration. Overdose should be managed with supportive and symptomatic treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diacomit •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Estiripentol Stiripentol Stiripentolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Stiripentol is an antiepileptic agent used in combination with other anticonvulsants to treat seizures associated with Dravet syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Streptozocin interact?

•Drug A: Abatacept •Drug B: Streptozocin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Streptozocin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malignant neoplasms of pancreas (metastatic islet cell carcinoma). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Streptozocin is an antitumour antibiotic consisting of a nitrosourea moiety interposed between a methyl group and a glucosamine. Streptozocin is indicated in the treatment of metastatic islet cell carcinoma of the pancreas. Streptozocin inhibits DNA synthesis in bacterial and mammalian cells. In bacterial cells, a specific interaction with cytosine moieties leads to degradation of DNA. The biochemical mechanism leading to mammalian cell death has not been definitely established; streptozocin inhibits cell proliferation at a considerably lower level than that needed to inhibit precursor incorporation into DNA or to inhibit several of the enzymes involved in DNA synthesis. Although streptozocin inhibits the progression of cells into mitosis, no specific phase of the cell cycle is particularly sensitive to its lethal effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although its mechanism of action is not completely clear, streptozocin is known to inhibit DNA synthesis, interfere with biochemical reactions of NAD and NADH, and inhibit some enzymes involved in gluconeogenesis. Its activity appears to occur as a result of formation of methylcarbonium ions, which alkylate or bind with many intracellular molecular structures including nucleic acids. Its cytotoxic action is probably due to cross-linking of strands of DNA, resulting in inhibition of DNA synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Poor oral absorption (17-25%) •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As much as 20% of the drug (or metabolites containing an N-nitrosourea group) is metabolized and/or excreted by the kidney. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5-15 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include nausea and vomiting, anorexia, myelosuppression; and nephrotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zanosar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Estreptozocina Streptozocin Streptozocine Streptozocinium Streptozocinum Streptozotocin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Streptozocin is a nitrosourea antineoplastic agent used in the treatment of metastatic pancreatic islet cell carcinoma.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Streptozocin interact? Information: •Drug A: Abatacept •Drug B: Streptozocin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Streptozocin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of malignant neoplasms of pancreas (metastatic islet cell carcinoma). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Streptozocin is an antitumour antibiotic consisting of a nitrosourea moiety interposed between a methyl group and a glucosamine. Streptozocin is indicated in the treatment of metastatic islet cell carcinoma of the pancreas. Streptozocin inhibits DNA synthesis in bacterial and mammalian cells. In bacterial cells, a specific interaction with cytosine moieties leads to degradation of DNA. The biochemical mechanism leading to mammalian cell death has not been definitely established; streptozocin inhibits cell proliferation at a considerably lower level than that needed to inhibit precursor incorporation into DNA or to inhibit several of the enzymes involved in DNA synthesis. Although streptozocin inhibits the progression of cells into mitosis, no specific phase of the cell cycle is particularly sensitive to its lethal effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although its mechanism of action is not completely clear, streptozocin is known to inhibit DNA synthesis, interfere with biochemical reactions of NAD and NADH, and inhibit some enzymes involved in gluconeogenesis. Its activity appears to occur as a result of formation of methylcarbonium ions, which alkylate or bind with many intracellular molecular structures including nucleic acids. Its cytotoxic action is probably due to cross-linking of strands of DNA, resulting in inhibition of DNA synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Poor oral absorption (17-25%) •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As much as 20% of the drug (or metabolites containing an N-nitrosourea group) is metabolized and/or excreted by the kidney. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5-15 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include nausea and vomiting, anorexia, myelosuppression; and nephrotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zanosar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Estreptozocina Streptozocin Streptozocine Streptozocinium Streptozocinum Streptozotocin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Streptozocin is a nitrosourea antineoplastic agent used in the treatment of metastatic pancreatic islet cell carcinoma. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Sulfadiazine interact?

•Drug A: Abatacept •Drug B: Sulfadiazine •Severity: MODERATE •Description: The metabolism of Sulfadiazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of rheumatic fever and meningococcal meningitis •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sulfadiazine is a sulfonamide antibiotic. The sulfonamides are synthetic bacteriostatic antibiotics with a wide spectrum against most gram-positive and many gram-negative organisms. However, many strains of an individual species may be resistant. Sulfonamides inhibit multiplication of bacteria by acting as competitive inhibitors of p -aminobenzoic acid in the folic acid metabolism cycle. Bacterial sensitivity is the same for the various sulfonamides, and resistance to one sulfonamide indicates resistance to all. Most sulfonamides are readily absorbed orally. However, parenteral administration is difficult, since the soluble sulfonamide salts are highly alkaline and irritating to the tissues. The sulfonamides are widely distributed throughout all tissues. High levels are achieved in pleural, peritoneal, synovial, and ocular fluids. Although these drugs are no longer used to treat meningitis, CSF levels are high in meningeal infections. Their antibacterial action is inhibited by pus. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sulfadiazine is a competitive inhibitor of the bacterial enzyme dihydropteroate synthetase. This enzyme is needed for the proper processing of para-aminobenzoic acid (PABA) which is essential for folic acid synthesis. The inhibited reaction is necessary in these organisms for the synthesis of folic acid. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Sulfadiazine is excreted largely in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 in mouse is 1500 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-sulfanilamidopyrimidine Sulfadiazin Sulfadiazina Sulfadiazine Sulfadiazinum Sulfapyrimidine Sulphadiazine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sulfadiazine is a sulfonamide antibiotic used in a variety of infections, such as urinary tract infections, trachoma, and chancroid.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Sulfadiazine interact? Information: •Drug A: Abatacept •Drug B: Sulfadiazine •Severity: MODERATE •Description: The metabolism of Sulfadiazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of rheumatic fever and meningococcal meningitis •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sulfadiazine is a sulfonamide antibiotic. The sulfonamides are synthetic bacteriostatic antibiotics with a wide spectrum against most gram-positive and many gram-negative organisms. However, many strains of an individual species may be resistant. Sulfonamides inhibit multiplication of bacteria by acting as competitive inhibitors of p -aminobenzoic acid in the folic acid metabolism cycle. Bacterial sensitivity is the same for the various sulfonamides, and resistance to one sulfonamide indicates resistance to all. Most sulfonamides are readily absorbed orally. However, parenteral administration is difficult, since the soluble sulfonamide salts are highly alkaline and irritating to the tissues. The sulfonamides are widely distributed throughout all tissues. High levels are achieved in pleural, peritoneal, synovial, and ocular fluids. Although these drugs are no longer used to treat meningitis, CSF levels are high in meningeal infections. Their antibacterial action is inhibited by pus. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sulfadiazine is a competitive inhibitor of the bacterial enzyme dihydropteroate synthetase. This enzyme is needed for the proper processing of para-aminobenzoic acid (PABA) which is essential for folic acid synthesis. The inhibited reaction is necessary in these organisms for the synthesis of folic acid. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Sulfadiazine is excreted largely in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 in mouse is 1500 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-sulfanilamidopyrimidine Sulfadiazin Sulfadiazina Sulfadiazine Sulfadiazinum Sulfapyrimidine Sulphadiazine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sulfadiazine is a sulfonamide antibiotic used in a variety of infections, such as urinary tract infections, trachoma, and chancroid. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Sulfasalazine interact?

•Drug A: Abatacept •Drug B: Sulfasalazine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Sulfasalazine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In the US, sulfasalazine is indicated to treat mild to moderate ulcerative colitis and to prolong the remission period between acute attacks of ulcerative colitis. Sulfasalazine is also indicated as an adjunct therapy in severe ulcerative colitis. For the delayed-release tablet formulation, sulfasalazine is also indicated to treat rheumatoid arthritis in pediatric patients who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs or polyarticular-course juvenile rheumatoid arthritis with the same patients' characteristics. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The mode of action of sulfasalazine or its metabolites, 5-aminosalicylic acid and sulfapyridine, is still under investigation but may be related to the anti-inflammatory and/or immunomodulatory properties that have been observed in animal and in vitro models, to its affinity for connective tissue, and/or to the relatively high concentration it reaches in serous fluids, the liver, and intestinal walls, as demonstrated in autoradiographic studies in animals. In ulcerative colitis, clinical studies utilizing rectal administration of sulfasalazine, sulfapyridine, and 5-aminosalicylic acid have indicated that the major therapeutic action may reside in the 5-aminosalicylic acid moiety. The relative contribution of the parent drug and the major metabolites in rheumatoid arthritis is unknown. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the exact mechanism of action of sulfasalazine is not fully understood, it is thought to be mediated through the inhibition of various inflammatory molecules. Research have found that sulfasalazine and its metabolites, mesalazine and sulfapyridine, can inhibit leukotrienes and prostaglandins by blocking the cyclo-oxygenase and lipoxygenase pathway. Specific enzymes that were investigated include phospholipase A2, cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX2), and arachidonate 5-lipoxygenase. Inhibitory activities on other non-arachidonic acid derivatives have also been observed, including PPAR gamma, NF-Kb, and IkappaB kinases alpha and beta. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration of 1 g of sulfasalazine to 9 healthy males, less than 15% of a dose of sulfasalazine is absorbed as the parent drug. Detectable serum concentrations of sulfasalazine have been found in healthy subjects within 90 minutes after ingestion. Maximum concentrations of sulfasalazine occur between 3 and 12 hours post-ingestion, with the mean peak concentration (6 μg/mL) occurring at 6 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following intravenous injection, the calculated volume of distribution for sulfasalazine was 7.5 ± 1.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sulfasalazine is highly bound to albumin (>99.3%) while sulfapyridine is only about 70% bound to albumin. Acetylsulfapyridine, the principal metabolite of sulfapyridine, is approximately 90% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In the intestine, sulfasalazine is metabolized by intestinal bacteria to sulfapyridine and 5-aminosalicylic acid. Of the two species, sulfapyridine is relatively well absorbed from the intestine and highly metabolized, while 5-aminosalicylic acid is much less well absorbed. Approximately 15% of a dose of sulfasalazine is absorbed as the parent drug and is metabolized to some extent in the liver to the same two species. Sulfapyridine can also be metabolized to 5-hydroxysulfapyridine and N-acetyl-5-hydroxy sulfapyridine. 5-aminosalicylic acid is primarily metabolized in both the liver and intestine to N-acetyl-5 aminosalicylic acid via a non-acetylation phenotype-dependent route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Absorbed sulfapyridine and 5-aminosalicylic acid and their metabolites are primarily eliminated in the urine either as free metabolites or as glucuronide conjugates. The majority of 5-ASA stays within the colonic lumen and is excreted as 5-aminosalicylic acid and acetyl-5-aminosalicylic acid in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The observed plasma half-life for intravenous sulfasalazine is 7.6 ± 3.4 hours. In fast acetylators, the mean plasma half-life of sulfapyridine is 10.4 hours while in slow acetylators, it is 14.8 hours. Due to low plasma levels produced by 5-aminosalicylic acid after oral administration, reliable estimates of plasma half-life are not possible. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The calculated clearance of sulfasalazine following intravenous administration was 1 L/hr. Renal clearance was estimated to account for 37% of total clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Two-year oral carcinogenicity studies were conducted in male and female F344/N rats and B6C3F1 mice. Sulfasalazine was tested at 84 (496 mg/m2), 168 (991 mg/m2), and 337.5 (1991 mg/m2) mg/kg/day doses in rats. A statistically significant increase in the incidence of urinary bladder transitional cell papillomas was observed in male rats. In female rats, two (4%) of the 337.5 mg/kg rats had transitional cell papilloma of the kidney. The increased incidence of neoplasms in the urinary bladder and kidney of rats was also associated with an increase in renal calculi formation and hyperplasia of transitional cell epithelium. For the mouse study, sulfasalazine was tested at 675 (2025 mg/m2), 1350 (4050 mg/m2), and 2700 (8100 mg/m2) mg/kg/day. The incidence of hepatocellular adenoma or carcinoma in male and female mice was significantly greater than the control at all doses tested. Sulfasalazine did not show mutagenicity in the bacterial reverse mutation assay (Ames test) and in L51784 mouse lymphoma cell assay at the HGPRT gene. However, sulfasalazine showed an equivocal mutagenic response in the micronucleus assay of mouse and rat bone marrow and mouse peripheral RBC and in the sister chromatid exchange, chromosomal aberration, and micronucleus assays in lymphocytes obtained from humans. Impairment of male fertility was observed in reproductive studies performed in rats at a dose of 800 mg/kg/day (4800 mg/m2). Oligospermia and infertility have been described in men treated with sulfasalazine. Withdrawal of the drug appears to reverse these effects. There are no adequate and well-controlled studies of sulfasalazine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 6 times the human maintenance dose of 2 g/day based on body surface area and have revealed no evidence of impaired female fertility or harm to the fetus due to sulfasalazine. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. There have been case reports of neural tube defects (NTDs) in infants born to mothers who were exposed to sulfasalazine during pregnancy, but the role of sulfasalazine in these defects has not been established. However, oral sulfasalazine inhibits the absorption and metabolism of folic acid which may interfere with folic acid supplementation (see Drug Interactions) and diminish the effect of periconceptional folic acid supplementation that has been shown to decrease the risk of NTDs. A national survey evaluated the outcome of pregnancies associated with inflammatory bowel disease (IBD). In a group of 186 women treated with sulfasalazine alone or sulfasalazine and concomitant steroid therapy, the incidence of fetal morbidity and mortality was comparable to that for 245 untreated IBD pregnancies as well as to pregnancies in the general population. A study of 1,455 pregnancies associated with exposure to sulfonamides indicated that this group of drugs, including sulfasalazine, did not appear to be associated with fetal malformation. A review of the medical literature covering 1,155 pregnancies in women with ulcerative colitis suggested that the outcome was similar to that expected in the general population. No clinical studies have been performed to evaluate the effect of sulfasalazine on the growth development and functional maturation of children whose mothers received the drug during pregnancy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azulfidine, Salazopyrin, Salazopyrin En-tabs •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Azopyrin Salazosulfapiridina Salazosulfapyridine Salazosulfapyridinum Salicylazosulfapyridine Sulfasalazin Sulfasalazina Sulfasalazine Sulfasalazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sulfasalazine is a salicylate used to treat Crohn's disease, ulcerative colitis, and rheumatoid arthritis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Sulfasalazine interact? Information: •Drug A: Abatacept •Drug B: Sulfasalazine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Sulfasalazine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In the US, sulfasalazine is indicated to treat mild to moderate ulcerative colitis and to prolong the remission period between acute attacks of ulcerative colitis. Sulfasalazine is also indicated as an adjunct therapy in severe ulcerative colitis. For the delayed-release tablet formulation, sulfasalazine is also indicated to treat rheumatoid arthritis in pediatric patients who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs or polyarticular-course juvenile rheumatoid arthritis with the same patients' characteristics. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The mode of action of sulfasalazine or its metabolites, 5-aminosalicylic acid and sulfapyridine, is still under investigation but may be related to the anti-inflammatory and/or immunomodulatory properties that have been observed in animal and in vitro models, to its affinity for connective tissue, and/or to the relatively high concentration it reaches in serous fluids, the liver, and intestinal walls, as demonstrated in autoradiographic studies in animals. In ulcerative colitis, clinical studies utilizing rectal administration of sulfasalazine, sulfapyridine, and 5-aminosalicylic acid have indicated that the major therapeutic action may reside in the 5-aminosalicylic acid moiety. The relative contribution of the parent drug and the major metabolites in rheumatoid arthritis is unknown. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the exact mechanism of action of sulfasalazine is not fully understood, it is thought to be mediated through the inhibition of various inflammatory molecules. Research have found that sulfasalazine and its metabolites, mesalazine and sulfapyridine, can inhibit leukotrienes and prostaglandins by blocking the cyclo-oxygenase and lipoxygenase pathway. Specific enzymes that were investigated include phospholipase A2, cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX2), and arachidonate 5-lipoxygenase. Inhibitory activities on other non-arachidonic acid derivatives have also been observed, including PPAR gamma, NF-Kb, and IkappaB kinases alpha and beta. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration of 1 g of sulfasalazine to 9 healthy males, less than 15% of a dose of sulfasalazine is absorbed as the parent drug. Detectable serum concentrations of sulfasalazine have been found in healthy subjects within 90 minutes after ingestion. Maximum concentrations of sulfasalazine occur between 3 and 12 hours post-ingestion, with the mean peak concentration (6 μg/mL) occurring at 6 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following intravenous injection, the calculated volume of distribution for sulfasalazine was 7.5 ± 1.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Sulfasalazine is highly bound to albumin (>99.3%) while sulfapyridine is only about 70% bound to albumin. Acetylsulfapyridine, the principal metabolite of sulfapyridine, is approximately 90% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In the intestine, sulfasalazine is metabolized by intestinal bacteria to sulfapyridine and 5-aminosalicylic acid. Of the two species, sulfapyridine is relatively well absorbed from the intestine and highly metabolized, while 5-aminosalicylic acid is much less well absorbed. Approximately 15% of a dose of sulfasalazine is absorbed as the parent drug and is metabolized to some extent in the liver to the same two species. Sulfapyridine can also be metabolized to 5-hydroxysulfapyridine and N-acetyl-5-hydroxy sulfapyridine. 5-aminosalicylic acid is primarily metabolized in both the liver and intestine to N-acetyl-5 aminosalicylic acid via a non-acetylation phenotype-dependent route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Absorbed sulfapyridine and 5-aminosalicylic acid and their metabolites are primarily eliminated in the urine either as free metabolites or as glucuronide conjugates. The majority of 5-ASA stays within the colonic lumen and is excreted as 5-aminosalicylic acid and acetyl-5-aminosalicylic acid in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The observed plasma half-life for intravenous sulfasalazine is 7.6 ± 3.4 hours. In fast acetylators, the mean plasma half-life of sulfapyridine is 10.4 hours while in slow acetylators, it is 14.8 hours. Due to low plasma levels produced by 5-aminosalicylic acid after oral administration, reliable estimates of plasma half-life are not possible. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The calculated clearance of sulfasalazine following intravenous administration was 1 L/hr. Renal clearance was estimated to account for 37% of total clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Two-year oral carcinogenicity studies were conducted in male and female F344/N rats and B6C3F1 mice. Sulfasalazine was tested at 84 (496 mg/m2), 168 (991 mg/m2), and 337.5 (1991 mg/m2) mg/kg/day doses in rats. A statistically significant increase in the incidence of urinary bladder transitional cell papillomas was observed in male rats. In female rats, two (4%) of the 337.5 mg/kg rats had transitional cell papilloma of the kidney. The increased incidence of neoplasms in the urinary bladder and kidney of rats was also associated with an increase in renal calculi formation and hyperplasia of transitional cell epithelium. For the mouse study, sulfasalazine was tested at 675 (2025 mg/m2), 1350 (4050 mg/m2), and 2700 (8100 mg/m2) mg/kg/day. The incidence of hepatocellular adenoma or carcinoma in male and female mice was significantly greater than the control at all doses tested. Sulfasalazine did not show mutagenicity in the bacterial reverse mutation assay (Ames test) and in L51784 mouse lymphoma cell assay at the HGPRT gene. However, sulfasalazine showed an equivocal mutagenic response in the micronucleus assay of mouse and rat bone marrow and mouse peripheral RBC and in the sister chromatid exchange, chromosomal aberration, and micronucleus assays in lymphocytes obtained from humans. Impairment of male fertility was observed in reproductive studies performed in rats at a dose of 800 mg/kg/day (4800 mg/m2). Oligospermia and infertility have been described in men treated with sulfasalazine. Withdrawal of the drug appears to reverse these effects. There are no adequate and well-controlled studies of sulfasalazine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 6 times the human maintenance dose of 2 g/day based on body surface area and have revealed no evidence of impaired female fertility or harm to the fetus due to sulfasalazine. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. There have been case reports of neural tube defects (NTDs) in infants born to mothers who were exposed to sulfasalazine during pregnancy, but the role of sulfasalazine in these defects has not been established. However, oral sulfasalazine inhibits the absorption and metabolism of folic acid which may interfere with folic acid supplementation (see Drug Interactions) and diminish the effect of periconceptional folic acid supplementation that has been shown to decrease the risk of NTDs. A national survey evaluated the outcome of pregnancies associated with inflammatory bowel disease (IBD). In a group of 186 women treated with sulfasalazine alone or sulfasalazine and concomitant steroid therapy, the incidence of fetal morbidity and mortality was comparable to that for 245 untreated IBD pregnancies as well as to pregnancies in the general population. A study of 1,455 pregnancies associated with exposure to sulfonamides indicated that this group of drugs, including sulfasalazine, did not appear to be associated with fetal malformation. A review of the medical literature covering 1,155 pregnancies in women with ulcerative colitis suggested that the outcome was similar to that expected in the general population. No clinical studies have been performed to evaluate the effect of sulfasalazine on the growth development and functional maturation of children whose mothers received the drug during pregnancy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azulfidine, Salazopyrin, Salazopyrin En-tabs •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Azopyrin Salazosulfapiridina Salazosulfapyridine Salazosulfapyridinum Salicylazosulfapyridine Sulfasalazin Sulfasalazina Sulfasalazine Sulfasalazinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sulfasalazine is a salicylate used to treat Crohn's disease, ulcerative colitis, and rheumatoid arthritis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Sunitinib interact?

•Drug A: Abatacept •Drug B: Sunitinib •Severity: MAJOR •Description: The metabolism of Sunitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sunitinib is indicated for the following conditions: Treatment of adult patients with gastrointestinal stromal tumor (GIST) following disease progression on (or intolerance to) imatinib mesylate Treatment of adult patients with advanced renal cell carcinoma (RCC) Adjuvant treatment of adult patients at high risk of recurrent RCC following nephrectomy Treatment of progressive, well-differentiated pancreatic neuroendocrine tumors (pNET) in adult patients with unresectable locally advanced or metastatic disease •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sunitinib is an oral, small-molecule, multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA on January 26, 2006. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sunitinib is a small molecule that inhibits multiple RTKs, some of which are implicated in tumor growth, pathologic angiogenesis, and metastatic progression of cancer. Sunitinib was evaluated for its inhibitory activity against a variety of kinases (>80 kinases) and was identified as an inhibitor of platelet-derived growth factor receptors (PDGFRa and PDGFRb), vascular endothelial growth factor receptors (VEGFR1, VEGFR2 and VEGFR3), stem cell factor receptor (KIT), Fms-like tyrosine kinase-3 (FLT3), colony stimulating factor receptor Type 1 (CSF-1R), and the glial cell-line derived neurotrophic factor receptor (RET). Sunitinib inhibition of the activity of these RTKs has been demonstrated in biochemical and cellular assays, and inhibition of function has been demonstrated in cell proliferation assays. The primary metabolite exhibits similar potency compared to sunitinib in biochemical and cellular assays. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Maximum plasma concentrations (Cmax) of sunitinib are generally observed between 6 and 12 hours (Tmax) following oral administration. Food has no effect on the bioavailability of sunitinib. Sunitinib may be taken with or without food. The pharmacokinetics were similar in healthy volunteers and in the solid tumor patient populations tested, including patients with GIST and RCC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2230 L (apparent volume of distribution, Vd/F) •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Binding of sunitinib and its primary metabolite to human plasma protein in vitro was 95% and 90%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sunitinib is metabolized primarily by the cytochrome P450 enzyme, CYP3A4, to produce its primary active metabolite, which is further metabolized by CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Sunitinib is metabolized primarily by the cytochrome P450 enzyme, CYP3A4, to produce its primary active metabolite, which is further metabolized by CYP3A4. Elimination is primarily via feces. In a human mass balance study of [14C]sunitinib, 61% of the dose was eliminated in feces, with renal elimination accounting for 16% of the administered dose. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following administration of a single oral dose in healthy volunteers, the terminal half-lives of sunitinib and its primary active metabolite are approximately 40 to 60 hours and 80 to 110 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 34 - 62 L/h [Total oral clearance] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximally tolerated dose for rat, mouse, and dog when given orally is greater than 500 mg/kg. The maximally tolerated dose of a non-human primate is greater 1200 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sutent •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sunitinib is a receptor tyrosine kinase inhibitor and chemotherapeutic agent used for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Sunitinib interact? Information: •Drug A: Abatacept •Drug B: Sunitinib •Severity: MAJOR •Description: The metabolism of Sunitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sunitinib is indicated for the following conditions: Treatment of adult patients with gastrointestinal stromal tumor (GIST) following disease progression on (or intolerance to) imatinib mesylate Treatment of adult patients with advanced renal cell carcinoma (RCC) Adjuvant treatment of adult patients at high risk of recurrent RCC following nephrectomy Treatment of progressive, well-differentiated pancreatic neuroendocrine tumors (pNET) in adult patients with unresectable locally advanced or metastatic disease •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Sunitinib is an oral, small-molecule, multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA on January 26, 2006. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sunitinib is a small molecule that inhibits multiple RTKs, some of which are implicated in tumor growth, pathologic angiogenesis, and metastatic progression of cancer. Sunitinib was evaluated for its inhibitory activity against a variety of kinases (>80 kinases) and was identified as an inhibitor of platelet-derived growth factor receptors (PDGFRa and PDGFRb), vascular endothelial growth factor receptors (VEGFR1, VEGFR2 and VEGFR3), stem cell factor receptor (KIT), Fms-like tyrosine kinase-3 (FLT3), colony stimulating factor receptor Type 1 (CSF-1R), and the glial cell-line derived neurotrophic factor receptor (RET). Sunitinib inhibition of the activity of these RTKs has been demonstrated in biochemical and cellular assays, and inhibition of function has been demonstrated in cell proliferation assays. The primary metabolite exhibits similar potency compared to sunitinib in biochemical and cellular assays. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Maximum plasma concentrations (Cmax) of sunitinib are generally observed between 6 and 12 hours (Tmax) following oral administration. Food has no effect on the bioavailability of sunitinib. Sunitinib may be taken with or without food. The pharmacokinetics were similar in healthy volunteers and in the solid tumor patient populations tested, including patients with GIST and RCC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2230 L (apparent volume of distribution, Vd/F) •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Binding of sunitinib and its primary metabolite to human plasma protein in vitro was 95% and 90%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Sunitinib is metabolized primarily by the cytochrome P450 enzyme, CYP3A4, to produce its primary active metabolite, which is further metabolized by CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Sunitinib is metabolized primarily by the cytochrome P450 enzyme, CYP3A4, to produce its primary active metabolite, which is further metabolized by CYP3A4. Elimination is primarily via feces. In a human mass balance study of [14C]sunitinib, 61% of the dose was eliminated in feces, with renal elimination accounting for 16% of the administered dose. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following administration of a single oral dose in healthy volunteers, the terminal half-lives of sunitinib and its primary active metabolite are approximately 40 to 60 hours and 80 to 110 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 34 - 62 L/h [Total oral clearance] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximally tolerated dose for rat, mouse, and dog when given orally is greater than 500 mg/kg. The maximally tolerated dose of a non-human primate is greater 1200 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sutent •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sunitinib is a receptor tyrosine kinase inhibitor and chemotherapeutic agent used for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST). Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Sutimlimab interact?

•Drug A: Abatacept •Drug B: Sutimlimab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Sutimlimab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sutimlimab is indicated to treat hemolysis in adults with cold agglutinin disease (CAD) and decrease the need for red blood cell transfusion in these patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Following a single sutimlimab injection, >90% inhibition of the complement pathway was observed, and this inhibition was sustained when concentrations of sutimlimab were ≥100 mcg/mL. As sutimlimab can impair the complement-mediated immune response, patients requiring therapy should receive all appropriate vaccinations against encapsulated bacteria at least 2 weeks prior to its initiation. Patients undergoing treatment with sutimlimab are at a higher risk of serious infections, especially those caused by encapsulated bacteria such as Neisseria meningitides or Streptococcus pneumoniae, and should be monitored closely throughout therapy for evidence of developing or ongoing infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Hemolysis associated with cold agglutinin disease is driven by the activation of the complement system. Cold agglutinins transiently bind erythrocytes as they circulate through cooler parts of the body (e.g. the extremities) - as they circulate back to warmer areas, C1q esterase activates C4 and C2, which generates C3 convertase, an enzyme which cleaves C3 into C3a and C3b. At this stage, the erythrocytes tagged with C3b can be sequestered by macrophages in the reticuloendothelial system, ultimately leading to extravascular hemolysis. Alternatively, C3b may be further cleaved into C3c and C3d - if complement activation continues past the C3 step, the membrane attack complex with C5b-C9 may form, which causes intravascular hemolysis. Sutimlimab is a humanized IgG4 monoclonal antibody targeted at the complement C1s subunit, a serine protease responsible for the activation of the classic complement pathway. By inhibiting the complement cascade at the level of C1s, sutimlimab prevents the deposition of complement opsinins on erythrocytes, thus preventing their eventual hemolysis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): When administered at the approved weight-based recommended dosage, the exposure to sutimlimab increases proportionately with increasing dosage. Steady-state concentrations are achieved by week 7 of therapy. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): At steady-state, the volume of distribution of sutimlimab in patients with cold agglutinin disease was approximately 5.8 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As with other therapeutic proteins, sutimlimab likely undergoes catabolism to smaller peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): At the approved recommended dosage, the terminal elimination half-life of sutimlimab is 21 days. The half-life of sutimlimab varies at different doses due to target-mediated drug disposition at lower concentrations. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): At the approved recommended dosage, the clearance of sutimlimab is 0.14 L/day. The clearance of sutimlimab varies at different doses due to target-mediated drug disposition at lower concentrations. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enjaymo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sutimlimab •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sutimlimab is a monoclonal antibody directed towards complement subunit C1s used to reduce the need for blood transfusion due to hemolysis in patients with cold agglutinin disease.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Sutimlimab interact? Information: •Drug A: Abatacept •Drug B: Sutimlimab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Sutimlimab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Sutimlimab is indicated to treat hemolysis in adults with cold agglutinin disease (CAD) and decrease the need for red blood cell transfusion in these patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Following a single sutimlimab injection, >90% inhibition of the complement pathway was observed, and this inhibition was sustained when concentrations of sutimlimab were ≥100 mcg/mL. As sutimlimab can impair the complement-mediated immune response, patients requiring therapy should receive all appropriate vaccinations against encapsulated bacteria at least 2 weeks prior to its initiation. Patients undergoing treatment with sutimlimab are at a higher risk of serious infections, especially those caused by encapsulated bacteria such as Neisseria meningitides or Streptococcus pneumoniae, and should be monitored closely throughout therapy for evidence of developing or ongoing infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Hemolysis associated with cold agglutinin disease is driven by the activation of the complement system. Cold agglutinins transiently bind erythrocytes as they circulate through cooler parts of the body (e.g. the extremities) - as they circulate back to warmer areas, C1q esterase activates C4 and C2, which generates C3 convertase, an enzyme which cleaves C3 into C3a and C3b. At this stage, the erythrocytes tagged with C3b can be sequestered by macrophages in the reticuloendothelial system, ultimately leading to extravascular hemolysis. Alternatively, C3b may be further cleaved into C3c and C3d - if complement activation continues past the C3 step, the membrane attack complex with C5b-C9 may form, which causes intravascular hemolysis. Sutimlimab is a humanized IgG4 monoclonal antibody targeted at the complement C1s subunit, a serine protease responsible for the activation of the classic complement pathway. By inhibiting the complement cascade at the level of C1s, sutimlimab prevents the deposition of complement opsinins on erythrocytes, thus preventing their eventual hemolysis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): When administered at the approved weight-based recommended dosage, the exposure to sutimlimab increases proportionately with increasing dosage. Steady-state concentrations are achieved by week 7 of therapy. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): At steady-state, the volume of distribution of sutimlimab in patients with cold agglutinin disease was approximately 5.8 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): As with other therapeutic proteins, sutimlimab likely undergoes catabolism to smaller peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): At the approved recommended dosage, the terminal elimination half-life of sutimlimab is 21 days. The half-life of sutimlimab varies at different doses due to target-mediated drug disposition at lower concentrations. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): At the approved recommended dosage, the clearance of sutimlimab is 0.14 L/day. The clearance of sutimlimab varies at different doses due to target-mediated drug disposition at lower concentrations. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Enjaymo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Sutimlimab •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Sutimlimab is a monoclonal antibody directed towards complement subunit C1s used to reduce the need for blood transfusion due to hemolysis in patients with cold agglutinin disease. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Suvorexant interact?

•Drug A: Abatacept •Drug B: Suvorexant •Severity: MODERATE •Description: The metabolism of Suvorexant can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Suvorexant is indicated for the treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Suvorexant is a dual antagonist of orexin receptors OX1R and OX2R. It exerts its pharmacological effect by inhibiting binding of neuropeptides orexin A and B, also known as hypocretin 1 and 2, that are produced by neurons in the lateral hypothalamus. These neurons control the wake-promoting centers of the brain and are active during wakefulness, especially during motor activities, and stop firing during sleep. By inhibiting the reinforcement of arousal systems, suvorexant use causes a decrease in arousal and wakefulness, rather than having a direct sleep-promoting effect. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Peak concentrations occur at a median Tmax of 2 hours under fasted conditions. Ingestion of suvorexant with a high-fat meal has no effect on AUC or Cmax, but may delay Tmax by approximately 1.5 hours. Mean absolute bioavailability of 10 mg is 82%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Mean volume of distribution is approximately 49 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Suvorexant is extensively bound (>99%) to human plasma proteins and does not preferentially distribute into red blood cells. It binds to both human serum albumin and alpha1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Suvorexant is primarily metabolized by cytochrome-P450 3A4 enzyme (CYP3A4) with a minor contribution from CYP2C19. Major circulating metabolites are suvorexant and a hydroxy-suvorexant metabolite, which is not expected to be pharmacologically active. There is potential for drug-drug interactions with drugs that inhibit or induce CYP3A4 activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 66% is eliminated in feces and 23% is eliminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Mean half life is approximately 12 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Dose-related somnolence and CNS depression are the most common adverse effects associated with the use of suvorexant. It has also been shown to impair driving skills and may increase the risk of falling asleep while driving. Next-day impairments are found to be highest if suvorexant is taken with less than a full night of sleep remaining, with higher doses, or if co-administered with other CNS depressants or CYP3A inhibitors. Complex behaviours such as sleep driving, preparing and eating food, and making phone calls have been reported in association with the use of hypnotics such as suvorexant. A dose-dependant increase in suicidal ideation has been observed, especially in patients with a previous diagnosis of depression. Sleep paralysis, hypnagogic/hypnopompic hallucinations including vivid and disturbing perceptions, and mild cataplexy have also been reported. There are no adequate studies in pregnant women to ensure its safety during pregnancy or breast feeding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Belsomra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Suvorexant is a orexin receptor antagonist used to treat insomnia that is characterized by difficulties with sleep onset and/or sleep maintenance.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Suvorexant interact? Information: •Drug A: Abatacept •Drug B: Suvorexant •Severity: MODERATE •Description: The metabolism of Suvorexant can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Suvorexant is indicated for the treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Suvorexant is a dual antagonist of orexin receptors OX1R and OX2R. It exerts its pharmacological effect by inhibiting binding of neuropeptides orexin A and B, also known as hypocretin 1 and 2, that are produced by neurons in the lateral hypothalamus. These neurons control the wake-promoting centers of the brain and are active during wakefulness, especially during motor activities, and stop firing during sleep. By inhibiting the reinforcement of arousal systems, suvorexant use causes a decrease in arousal and wakefulness, rather than having a direct sleep-promoting effect. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Peak concentrations occur at a median Tmax of 2 hours under fasted conditions. Ingestion of suvorexant with a high-fat meal has no effect on AUC or Cmax, but may delay Tmax by approximately 1.5 hours. Mean absolute bioavailability of 10 mg is 82%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Mean volume of distribution is approximately 49 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Suvorexant is extensively bound (>99%) to human plasma proteins and does not preferentially distribute into red blood cells. It binds to both human serum albumin and alpha1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Suvorexant is primarily metabolized by cytochrome-P450 3A4 enzyme (CYP3A4) with a minor contribution from CYP2C19. Major circulating metabolites are suvorexant and a hydroxy-suvorexant metabolite, which is not expected to be pharmacologically active. There is potential for drug-drug interactions with drugs that inhibit or induce CYP3A4 activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 66% is eliminated in feces and 23% is eliminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Mean half life is approximately 12 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Dose-related somnolence and CNS depression are the most common adverse effects associated with the use of suvorexant. It has also been shown to impair driving skills and may increase the risk of falling asleep while driving. Next-day impairments are found to be highest if suvorexant is taken with less than a full night of sleep remaining, with higher doses, or if co-administered with other CNS depressants or CYP3A inhibitors. Complex behaviours such as sleep driving, preparing and eating food, and making phone calls have been reported in association with the use of hypnotics such as suvorexant. A dose-dependant increase in suicidal ideation has been observed, especially in patients with a previous diagnosis of depression. Sleep paralysis, hypnagogic/hypnopompic hallucinations including vivid and disturbing perceptions, and mild cataplexy have also been reported. There are no adequate studies in pregnant women to ensure its safety during pregnancy or breast feeding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Belsomra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Suvorexant is a orexin receptor antagonist used to treat insomnia that is characterized by difficulties with sleep onset and/or sleep maintenance. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Does Abatacept and Tacrolimus interact?

•Drug A: Abatacept •Drug B: Tacrolimus •Severity: MODERATE •Description: Tacrolimus may increase the immunosuppressive activities of Abatacept. •Extended Description: Tacrolimus is an immunosuppressant with a potential to induce infections, lymphoma and other malignancies, particularly with long-term use. The concomitant use of tacrolimus with other immunosuppressive agents may create an additive effect and lead to an increased risk of immunosuppression-related adverse reactions. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Immediate-release formulations of tacrolimus are indicated for the prophylaxis of organ rejection in adult and pediatric patients receiving allogeneic liver, kidney, heart, or lung transplants, in combination with other immunosuppressants. Extended-release formulations of tacrolimus are indicated for the prophylaxis of organ rejection in adult and pediatric patients receiving kidney transplants, in combination with other immunosuppressants, and may be used in patients converted from immediate-release formulations. Topical tacrolimus ointment is indicated as second-line therapy for short-term and non-continuous treatment of moderate-to-severe atopic dermatitis in non-immunocompromised adults and children who have failed to respond adequately to other topical treatments or for whom alternative treatments are not advisable. Both available strengths are indicated in adult patients, while only the lower strength (0.03%) formulation is indicated in pediatric patients between 2 and 15 years of age. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tacrolimus acts by reducing peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This inhibits both T-lymphocyte signal transduction and IL-2 transcription. Tacrolimus has similar activity to cyclosporine but rates of rejection are lower with tacrolimus. Tacrolimus has also been shown to be effective in the topical treatment of eczema, particularly atopic eczema. It suppresses inflammation in a similar way to steroids, but is not as powerful. An important dermatological advantage of tacrolimus is that it can be used directly on the face; topical steroids cannot be used on the face, as they thin the skin dramatically there. On other parts of the body, topical steroid are generally a better treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of tacrolimus in atopic dermatitis is not known. While the following have been observed, the clinical significance of these observations in atopic dermatitis is not known. It has been demonstrated that tacrolimus inhibits T-lymphocyte activation by first binding to an intracellular protein, FKBP-12. A complex of tacrolimus-FKBP-12, calcium, calmodulin, and calcineurin is then formed and the phosphatase activity of calcineurin is inhibited. This prevents the dephosphorylation and translocation of nuclear factor of activated T-cells (NF-AT), a nuclear component thought to initiate gene transcription for the formation of lymphokines. Tacrolimus also inhibits the transcription for genes which encode IL-3, IL-4, IL-5, GM-CSF, and TNF-, all of which are involved in the early stages of T-cell activation. Additionally, tacrolimus has been shown to inhibit the release of pre-formed mediators from skin mast cells and basophils, and to downregulate the expression of FceRI on Langerhans cells. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption of tacrolimus from the gastrointestinal tract after oral administration is incomplete and variable. The absolute bioavailability in adult kidney transplant patients is 17±10%; in adults liver transplant patients is 22±6%; in healthy subjects is 18±5%. The absolute bioavailability in pediatric liver transplant patients was 31±24%. Tacrolimus maximum blood concentrations (Cmax) and area under the curve (AUC) appeared to increase in a dose-proportional fashion in 18 fasted healthy volunteers receiving a single oral dose of 3, 7, and 10 mg. When given without food, the rate and extent of absorption were the greatest. The time of the meal also affected bioavailability. When given immediately after a meal, mean Cmax was reduced 71%, and mean AUC was reduced 39%, relative to the fasted condition. When administered 1.5 hours following the meal, mean Cmax was reduced 63%, and mean AUC was reduced 39%, relative to the fasted condition. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2.6 ± 2.1 L/kg [pediatric liver transplant patients] 1.07 ± 0.20 L/kg [patients with renal impairment, 0.02 mg/kg/4 hr dose, IV] 3.1 ± 1.6 L/kg [Mild Hepatic Impairment, 0.02 mg/kg/4 hr dose, IV] 3.7 ± 4.7 L/kg [Mild Hepatic Impairment, 7.7 mg dose, PO] 3.9 ± 1.0 L/kg [Severe hepatic impairment, 0.02 mg/kg/4 hr dose, IV] 3.1 ± 3.4 L/kg [Severe hepatic impairment, 8 mg dose, PO] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~99% bound to human plasma protein, primarily to albumin and alpha-1-acid glycoprotein. This is independent of concentration over a range of 5-50 ng/mL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of tacrolimus is predominantly mediated by CYP3A4 and secondarily by CYP3A5. Tacrolimus is metabolized into 8 metabolites: 13-demethyl tacrolimus, 31-demethyl tacrolimus, 15-demethyl tacrolimus, 12-hydroxy tacrolimus, 15,31-didemethyl tacrolimus, 13,31-didemethyl tacrolimus, 13,15-didemethyl tacrolimus, and a final metabolite involving O-demethylation and the formation of a fused ring. The major metabolite identified in incubations with human liver microsomes is 13-demethyl tacrolimus. In in vitro studies, a 31-demethyl metabolite has been reported to have the same activity as tacrolimus. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In man, less than 1% of the dose administered is excreted unchanged in urine. When administered IV, fecal elimination accounted for 92.6±30.7%, urinary elimination accounted for 2.3±1.1%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life in adult healthy volunteers, kidney transplant patients, liver transplants patients, and heart transplant patients are approximately 35, 19, 12, 24 hours, respectively. The elimination half life in pediatric liver transplant patients was 11.5±3.8 hours, in pediatric kidney transplant patients was 10.2±5.0 (range 3.4-25) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 0.040 L/hr/kg [healthy subjects, IV] 0.172 ± 0.088 L/hr/kg [healthy subjects, oral] 0.083 L/hr/kg [adult kidney transplant patients, IV] 0.053 L/hr/kg [adult liver transplant patients, IV] 0.051 L/hr/kg [adult heart transplant patients, IV] 0.138 ± 0.071 L/hr/kg [pediatric liver transplant patients] 0.12 ± 0.04 (range 0.06-0.17) L/hr/kg [pediatric kidney transplant patients] 0.038 ± 0.014 L/hr/kg [patients with renal impairment, 0.02 mg/kg/4 hr dose, IV] 0.042 ± 0.02 L/hr/kg [Mild Hepatic Impairment, 0.02 mg/kg/4 hr dose, IV] 0.034 ± 0.019 L/hr/kg [Mild Hepatic Impairment, 7.7 mg dose, PO] 0.017 ± 0.013 L/hr/kg [Severe hepatic impairment, 0.02 mg/kg/4 hr dose, IV] 0.016 ± 0.011 L/hr/kg [Severe hepatic impairment, 8 mg dose, PO] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects can be severe and include blurred vision, liver and kidney problems (it is nephrotoxic), seizures, tremors, hypertension, hypomagnesemia, diabetes mellitus, hyperkalemia, itching, insomnia, confusion. LD 50 =134-194 mg/kg (rat). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Advagraf, Astagraf, Envarsus, Modigraf, Prograf, Protopic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tacrolimus •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tacrolimus is a calcineurin inhibitor used to prevent organ transplant rejection and to treat moderate to severe atopic dermatitis.

Tacrolimus is an immunosuppressant with a potential to induce infections, lymphoma and other malignancies, particularly with long-term use. The concomitant use of tacrolimus with other immunosuppressive agents may create an additive effect and lead to an increased risk of immunosuppression-related adverse reactions. The severity of the interaction is moderate.

Question: Does Abatacept and Tacrolimus interact? Information: •Drug A: Abatacept •Drug B: Tacrolimus •Severity: MODERATE •Description: Tacrolimus may increase the immunosuppressive activities of Abatacept. •Extended Description: Tacrolimus is an immunosuppressant with a potential to induce infections, lymphoma and other malignancies, particularly with long-term use. The concomitant use of tacrolimus with other immunosuppressive agents may create an additive effect and lead to an increased risk of immunosuppression-related adverse reactions. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Immediate-release formulations of tacrolimus are indicated for the prophylaxis of organ rejection in adult and pediatric patients receiving allogeneic liver, kidney, heart, or lung transplants, in combination with other immunosuppressants. Extended-release formulations of tacrolimus are indicated for the prophylaxis of organ rejection in adult and pediatric patients receiving kidney transplants, in combination with other immunosuppressants, and may be used in patients converted from immediate-release formulations. Topical tacrolimus ointment is indicated as second-line therapy for short-term and non-continuous treatment of moderate-to-severe atopic dermatitis in non-immunocompromised adults and children who have failed to respond adequately to other topical treatments or for whom alternative treatments are not advisable. Both available strengths are indicated in adult patients, while only the lower strength (0.03%) formulation is indicated in pediatric patients between 2 and 15 years of age. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tacrolimus acts by reducing peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This inhibits both T-lymphocyte signal transduction and IL-2 transcription. Tacrolimus has similar activity to cyclosporine but rates of rejection are lower with tacrolimus. Tacrolimus has also been shown to be effective in the topical treatment of eczema, particularly atopic eczema. It suppresses inflammation in a similar way to steroids, but is not as powerful. An important dermatological advantage of tacrolimus is that it can be used directly on the face; topical steroids cannot be used on the face, as they thin the skin dramatically there. On other parts of the body, topical steroid are generally a better treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of tacrolimus in atopic dermatitis is not known. While the following have been observed, the clinical significance of these observations in atopic dermatitis is not known. It has been demonstrated that tacrolimus inhibits T-lymphocyte activation by first binding to an intracellular protein, FKBP-12. A complex of tacrolimus-FKBP-12, calcium, calmodulin, and calcineurin is then formed and the phosphatase activity of calcineurin is inhibited. This prevents the dephosphorylation and translocation of nuclear factor of activated T-cells (NF-AT), a nuclear component thought to initiate gene transcription for the formation of lymphokines. Tacrolimus also inhibits the transcription for genes which encode IL-3, IL-4, IL-5, GM-CSF, and TNF-, all of which are involved in the early stages of T-cell activation. Additionally, tacrolimus has been shown to inhibit the release of pre-formed mediators from skin mast cells and basophils, and to downregulate the expression of FceRI on Langerhans cells. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption of tacrolimus from the gastrointestinal tract after oral administration is incomplete and variable. The absolute bioavailability in adult kidney transplant patients is 17±10%; in adults liver transplant patients is 22±6%; in healthy subjects is 18±5%. The absolute bioavailability in pediatric liver transplant patients was 31±24%. Tacrolimus maximum blood concentrations (Cmax) and area under the curve (AUC) appeared to increase in a dose-proportional fashion in 18 fasted healthy volunteers receiving a single oral dose of 3, 7, and 10 mg. When given without food, the rate and extent of absorption were the greatest. The time of the meal also affected bioavailability. When given immediately after a meal, mean Cmax was reduced 71%, and mean AUC was reduced 39%, relative to the fasted condition. When administered 1.5 hours following the meal, mean Cmax was reduced 63%, and mean AUC was reduced 39%, relative to the fasted condition. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 2.6 ± 2.1 L/kg [pediatric liver transplant patients] 1.07 ± 0.20 L/kg [patients with renal impairment, 0.02 mg/kg/4 hr dose, IV] 3.1 ± 1.6 L/kg [Mild Hepatic Impairment, 0.02 mg/kg/4 hr dose, IV] 3.7 ± 4.7 L/kg [Mild Hepatic Impairment, 7.7 mg dose, PO] 3.9 ± 1.0 L/kg [Severe hepatic impairment, 0.02 mg/kg/4 hr dose, IV] 3.1 ± 3.4 L/kg [Severe hepatic impairment, 8 mg dose, PO] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~99% bound to human plasma protein, primarily to albumin and alpha-1-acid glycoprotein. This is independent of concentration over a range of 5-50 ng/mL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of tacrolimus is predominantly mediated by CYP3A4 and secondarily by CYP3A5. Tacrolimus is metabolized into 8 metabolites: 13-demethyl tacrolimus, 31-demethyl tacrolimus, 15-demethyl tacrolimus, 12-hydroxy tacrolimus, 15,31-didemethyl tacrolimus, 13,31-didemethyl tacrolimus, 13,15-didemethyl tacrolimus, and a final metabolite involving O-demethylation and the formation of a fused ring. The major metabolite identified in incubations with human liver microsomes is 13-demethyl tacrolimus. In in vitro studies, a 31-demethyl metabolite has been reported to have the same activity as tacrolimus. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In man, less than 1% of the dose administered is excreted unchanged in urine. When administered IV, fecal elimination accounted for 92.6±30.7%, urinary elimination accounted for 2.3±1.1%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life in adult healthy volunteers, kidney transplant patients, liver transplants patients, and heart transplant patients are approximately 35, 19, 12, 24 hours, respectively. The elimination half life in pediatric liver transplant patients was 11.5±3.8 hours, in pediatric kidney transplant patients was 10.2±5.0 (range 3.4-25) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 0.040 L/hr/kg [healthy subjects, IV] 0.172 ± 0.088 L/hr/kg [healthy subjects, oral] 0.083 L/hr/kg [adult kidney transplant patients, IV] 0.053 L/hr/kg [adult liver transplant patients, IV] 0.051 L/hr/kg [adult heart transplant patients, IV] 0.138 ± 0.071 L/hr/kg [pediatric liver transplant patients] 0.12 ± 0.04 (range 0.06-0.17) L/hr/kg [pediatric kidney transplant patients] 0.038 ± 0.014 L/hr/kg [patients with renal impairment, 0.02 mg/kg/4 hr dose, IV] 0.042 ± 0.02 L/hr/kg [Mild Hepatic Impairment, 0.02 mg/kg/4 hr dose, IV] 0.034 ± 0.019 L/hr/kg [Mild Hepatic Impairment, 7.7 mg dose, PO] 0.017 ± 0.013 L/hr/kg [Severe hepatic impairment, 0.02 mg/kg/4 hr dose, IV] 0.016 ± 0.011 L/hr/kg [Severe hepatic impairment, 8 mg dose, PO] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Side effects can be severe and include blurred vision, liver and kidney problems (it is nephrotoxic), seizures, tremors, hypertension, hypomagnesemia, diabetes mellitus, hyperkalemia, itching, insomnia, confusion. LD 50 =134-194 mg/kg (rat). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Advagraf, Astagraf, Envarsus, Modigraf, Prograf, Protopic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tacrolimus •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tacrolimus is a calcineurin inhibitor used to prevent organ transplant rejection and to treat moderate to severe atopic dermatitis. Output: Tacrolimus is an immunosuppressant with a potential to induce infections, lymphoma and other malignancies, particularly with long-term use. The concomitant use of tacrolimus with other immunosuppressive agents may create an additive effect and lead to an increased risk of immunosuppression-related adverse reactions. The severity of the interaction is moderate.

Does Abatacept and Tadalafil interact?

•Drug A: Abatacept •Drug B: Tadalafil •Severity: MODERATE •Description: The metabolism of Tadalafil can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tadalafil is indicated for the treatment of erectile dysfunction (ED) and either alone or in combination with finasteride for the treatment of benign prostatic hypertrophy (BPH). It is also indicated for the treatment of pulmonary arterial hypertension (PAH) both alone and in combination with macitentan or other endothelin-1 antagonists. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tadalafil exerts a therapeutic effect in ED by increasing sexual stimulation-dependant smooth muscle relaxation in the penis, allowing the corpus cavernosum to fill with blood to produce an erection. Smooth muscle relaxation in the pulmonary vasculature helps to produce vasodilation in PAH which reduces blood pressure in the pulmonary arteries. In BPH, tadalafil may contribute to decreased smooth muscle cell proliferation which may reduce the size of the prostate and relieve the anatomical obstruction which produces urinary symptoms of BPH. The decreased affinity of tadalafil for PDE6 compared to other PDE5 inhibitors may explain the reduced incidence of visual side effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tadalafil is a selective phosphodiesterase-5 (PDE5) inhibitor that produces several downstream effects with the most common therapeutic effect being smooth muscle relaxation. Patients may experience ED due to a variety of causes including psychogenic, neurogenic, vasculogenic, iatrogenic, or endocrine. These causes result in dysfunction of penile smooth muscle relaxation through either disrupted neuronal signaling or direct influence on smooth muscle cells. During sexual arousal, non-adrenergic non-cholinergic (NANC) neurons release nitric oxide (NO). Nitric oxide stimulates guanylate cyclase which converts guanosine triphosphate to cyclic guanosine monophosphate (cGMP). cGMP activates the cGMP-dependent kinase (PKG) in a signal cascade which activates K+ channels leading to inhibition of Ca2+ channels, inhibits platelet activation, and inhibits smooth muscle cell proliferation while inducing apoptosis. This signal cascade is attenuated by PDE5 which breaks the phosphodiester bond of cGMP, converting it to GMP. Inhibition of PDE5 by tadalafil increases signaling via the PKG cascade which supports penile smooth muscle relaxation during sexual arousal by decreasing Ca2+ entry into smooth muscle cells. This smooth muscle relaxation allows blood to fill the corpus cavernosum thereby producing an erection. In PAH, blood pressure in the pulmonary arteries is raised due to a variety of mechanisms stemming from endothelial dysfunction. Decreased production of NO and prostacyclin reduce vasodilatory signaling while overproduction of endothelin-1 and thromboxane increase vasoconstriction. Inflammation, thromboses, and hypoxia later contribute to vascular remodeling which further reduces luminal size. The resultant increase in blood pressure reduces the capacity for gas exchange and increases afterload at the right ventricle, producing symptoms of dyspnea, fatigue, and dizziness as well as leading to right-sided heart failure. Tadalafil exerts its therapeutic effect in PAH through boosting NO-cGMP signaling to contribute to smooth muscle relaxation as with ED. Lastly, tadalafil is used to treat BPH. BPH produces urinary dysfunction through hyperproliferation of the epithelial and smooth muscle layers of the prostate. The increased size of the prostate blocks urine flow through the urethra resulting in higher residual volumes due to incomplete emptying. Tadalafil does not appear to exert its benefit via smooth muscle relaxation of the prostate. It may instead exert its effect through a mix of increased oxygenation and decreased inflammation, which decreases tissue remodeling, and inhibition of cell proliferation through the cGMP cascade. The decreased affinity for PDE6 compared to other PDE5 inhibitors may explain the decreased incidence of visual side effects as PDE6 is present in the eye and contributes to color vision. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Tadalafil has a tmax of 0.5-6h with a median of 2h in healthy adults. The tmax in adults with PAH is reported as 2-8h with a median of 4h. There does not appear to be a significant effect on absorption when tadalafil is taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Tadalafil has a mean apparent volume of distribution of 63L in healthy adults. The mean apparent volume of distribution is reported as 77L in adults with PAH. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tadalafil is 94% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tadalafil undergoes hepatic metabolism via CYP3A4 to a catechol metabolite. This catechol metabolite undergoes subsequent methylation and glucuronidation with the methyl-glucuronide metabolite becoming the primary metabolite in circulation. None of the known metabolites are considered to be active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tadalafil is primarily eliminated via hepatic metabolism. These metabolites are mainly excreted in the feces (61%) and to a lesser extent in the urine (36%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean half-life of elimination of tadalafil is 15-17.5h in healthy adults. The mean half-life of elimination in adults with PAH is reported as 35h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean apparent oral clearance of tadalafil is 2.5-3.4L/h in healthy adults. The mean apparent oral clearance in adults with PAH is reported as 3.5L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose are expected to be similar to typical adverse effects which may include headache, dyspepsia, back pain, myalgia, nasopharyngitis, and dizziness. Standard supportive care is recommended. Hemodialysis is not expected to contribute significantly to tadalafil clearance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adcirca, Alyq, Cialis, Entadfi, Tadliq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tadalafil Tadalafilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tadalafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tadalafil interact? Information: •Drug A: Abatacept •Drug B: Tadalafil •Severity: MODERATE •Description: The metabolism of Tadalafil can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tadalafil is indicated for the treatment of erectile dysfunction (ED) and either alone or in combination with finasteride for the treatment of benign prostatic hypertrophy (BPH). It is also indicated for the treatment of pulmonary arterial hypertension (PAH) both alone and in combination with macitentan or other endothelin-1 antagonists. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tadalafil exerts a therapeutic effect in ED by increasing sexual stimulation-dependant smooth muscle relaxation in the penis, allowing the corpus cavernosum to fill with blood to produce an erection. Smooth muscle relaxation in the pulmonary vasculature helps to produce vasodilation in PAH which reduces blood pressure in the pulmonary arteries. In BPH, tadalafil may contribute to decreased smooth muscle cell proliferation which may reduce the size of the prostate and relieve the anatomical obstruction which produces urinary symptoms of BPH. The decreased affinity of tadalafil for PDE6 compared to other PDE5 inhibitors may explain the reduced incidence of visual side effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tadalafil is a selective phosphodiesterase-5 (PDE5) inhibitor that produces several downstream effects with the most common therapeutic effect being smooth muscle relaxation. Patients may experience ED due to a variety of causes including psychogenic, neurogenic, vasculogenic, iatrogenic, or endocrine. These causes result in dysfunction of penile smooth muscle relaxation through either disrupted neuronal signaling or direct influence on smooth muscle cells. During sexual arousal, non-adrenergic non-cholinergic (NANC) neurons release nitric oxide (NO). Nitric oxide stimulates guanylate cyclase which converts guanosine triphosphate to cyclic guanosine monophosphate (cGMP). cGMP activates the cGMP-dependent kinase (PKG) in a signal cascade which activates K+ channels leading to inhibition of Ca2+ channels, inhibits platelet activation, and inhibits smooth muscle cell proliferation while inducing apoptosis. This signal cascade is attenuated by PDE5 which breaks the phosphodiester bond of cGMP, converting it to GMP. Inhibition of PDE5 by tadalafil increases signaling via the PKG cascade which supports penile smooth muscle relaxation during sexual arousal by decreasing Ca2+ entry into smooth muscle cells. This smooth muscle relaxation allows blood to fill the corpus cavernosum thereby producing an erection. In PAH, blood pressure in the pulmonary arteries is raised due to a variety of mechanisms stemming from endothelial dysfunction. Decreased production of NO and prostacyclin reduce vasodilatory signaling while overproduction of endothelin-1 and thromboxane increase vasoconstriction. Inflammation, thromboses, and hypoxia later contribute to vascular remodeling which further reduces luminal size. The resultant increase in blood pressure reduces the capacity for gas exchange and increases afterload at the right ventricle, producing symptoms of dyspnea, fatigue, and dizziness as well as leading to right-sided heart failure. Tadalafil exerts its therapeutic effect in PAH through boosting NO-cGMP signaling to contribute to smooth muscle relaxation as with ED. Lastly, tadalafil is used to treat BPH. BPH produces urinary dysfunction through hyperproliferation of the epithelial and smooth muscle layers of the prostate. The increased size of the prostate blocks urine flow through the urethra resulting in higher residual volumes due to incomplete emptying. Tadalafil does not appear to exert its benefit via smooth muscle relaxation of the prostate. It may instead exert its effect through a mix of increased oxygenation and decreased inflammation, which decreases tissue remodeling, and inhibition of cell proliferation through the cGMP cascade. The decreased affinity for PDE6 compared to other PDE5 inhibitors may explain the decreased incidence of visual side effects as PDE6 is present in the eye and contributes to color vision. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Tadalafil has a tmax of 0.5-6h with a median of 2h in healthy adults. The tmax in adults with PAH is reported as 2-8h with a median of 4h. There does not appear to be a significant effect on absorption when tadalafil is taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Tadalafil has a mean apparent volume of distribution of 63L in healthy adults. The mean apparent volume of distribution is reported as 77L in adults with PAH. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tadalafil is 94% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tadalafil undergoes hepatic metabolism via CYP3A4 to a catechol metabolite. This catechol metabolite undergoes subsequent methylation and glucuronidation with the methyl-glucuronide metabolite becoming the primary metabolite in circulation. None of the known metabolites are considered to be active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tadalafil is primarily eliminated via hepatic metabolism. These metabolites are mainly excreted in the feces (61%) and to a lesser extent in the urine (36%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean half-life of elimination of tadalafil is 15-17.5h in healthy adults. The mean half-life of elimination in adults with PAH is reported as 35h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The mean apparent oral clearance of tadalafil is 2.5-3.4L/h in healthy adults. The mean apparent oral clearance in adults with PAH is reported as 3.5L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose are expected to be similar to typical adverse effects which may include headache, dyspepsia, back pain, myalgia, nasopharyngitis, and dizziness. Standard supportive care is recommended. Hemodialysis is not expected to contribute significantly to tadalafil clearance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adcirca, Alyq, Cialis, Entadfi, Tadliq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tadalafil Tadalafilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tadalafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Tafenoquine interact?

•Drug A: Abatacept •Drug B: Tafenoquine •Severity: MODERATE •Description: The metabolism of Tafenoquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tafenoquine is used for the treatment and prevention of relapse of Vivax malaria in patients 16 years and older. Tafenoquine is not indicated to treat acute vivax malaria. Malaria is a disease that remains to occur in many tropical countries. Vivax malaria, caused by Plasmodium vivax, is known to be less virulent and seldom causes death. However, it causes a substantive illness-related burden in endemic areas and it is known to present dormant forms in the hepatocytes named hypnozoites which can remain dormant for weeks or even months. This dormant form produces ongoing relapses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro studies have shown that tafenoquine presents an average 50% inhibitory concentration of 0.436 mcg against blood stages of seven strains of P. falciparum. In chloroquine-resistant P. falciparum strains the IC50 of tafenoquine was greater when compared with primaquine and it ranged from 0.5 to 33.1 mcg. In studies evaluating the transmission-blocking activity of tafenoquine against the sporogonic stage of P. vivax, it was showed a reduced transmission at doses higher than 25 mg/kg. In clinical trials, it was reported a tafenoquine-induced relapse prevention of 91.9% in cases of vivax malaria when pretreated with chloroquine. In prophylactic studies, tafenoquine showed an efficacy range from 84 to 87% against falciparum malaria and 99.1% against vivax malaria. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of tafenoquine is not well established but studies have reported a longer and more effective action when compared to primaquine. The active moiety of tafenoquine, 5,6 ortho quinone tafenoquine, seems to be redox cycled by P. falciparum which are upregulated in gametocytes and liver stages. Once inside, the oxidated metabolite produces hydrogen peroxide and hydroxyl radicals. It is thought that these radicals produce leads to the parasite death. On the other hand, tafenoquine inhibits heme polymerase in blood stage of parasites which explains the activity against blood stages of parasites. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The first-in-human pharmacokinetic study showed a tmax of 13.8 hours and this study suggested that the prolonged absorption from the gut can be due to absorption in the distal gastrointestinal tract combined with a slow clearance. The AUC and Cmax demonstrated an intersubject variability. The bioavailability of tafenoquine is increased in the presence of a high-fat meal by modifying the amount of drug absorbed rather than the rate of absorption. Once absorbed, the concentration of tafenoquine in the whole body is two-fold higher than the corresponding concentration in plasma and it seems to be highly distributed in the liver showing an AUC of approximately 80 times more than what is found in the plasma. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Tafenoquine presents a high volume of distribution of approximately 2 560 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of tafenoquine in humans is very high and it represents about 99.5%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The activation of tafenoquine needs the activity of CYP 2D6 liver microsomal enzyme. This activation step produces the metabolite 5,6 ortho quinone tafenoquine. This metabolite is internalized by the parasite and reduced to radicals by ferredoxin-NADP+ reductase and diflavin reductase enzymes. In the human, tafenoquine is metabolized by several metabolic pathways including O-demethylation, N-dealkylation, N-oxidation and oxidative deamination as well as C-hydroxylation of the 8-aminoalkylamino side chain. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After degradation by different metabolic pathways, tafenoquine is slowly excreted from the body primarily in the feces and renal elimination of the unchanged form is very low. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Tafenoquine presents a long half-life of approximately 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Tafenoquine presents a low clearance of approximately 6 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Tafenoquine can cause hemolysis in people with glucose-6-phosphate dehydrogenase deficiency. In preclinical studies, renal cell adenomas and carcinomas are increased in male rats with an overdose administration. However, this drug does not seem to be carcinogenic in humans and it was shown to lack mutagenic potential. In fertility studies, tafenoquine resulted in a reduced number of viable fetuses, implantation sites and corpora lutea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arakoda, Krintafel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tafenoquine is an antiparasitic agent used for the treatment and prevention of relapse of Vivax malaria.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tafenoquine interact? Information: •Drug A: Abatacept •Drug B: Tafenoquine •Severity: MODERATE •Description: The metabolism of Tafenoquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tafenoquine is used for the treatment and prevention of relapse of Vivax malaria in patients 16 years and older. Tafenoquine is not indicated to treat acute vivax malaria. Malaria is a disease that remains to occur in many tropical countries. Vivax malaria, caused by Plasmodium vivax, is known to be less virulent and seldom causes death. However, it causes a substantive illness-related burden in endemic areas and it is known to present dormant forms in the hepatocytes named hypnozoites which can remain dormant for weeks or even months. This dormant form produces ongoing relapses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro studies have shown that tafenoquine presents an average 50% inhibitory concentration of 0.436 mcg against blood stages of seven strains of P. falciparum. In chloroquine-resistant P. falciparum strains the IC50 of tafenoquine was greater when compared with primaquine and it ranged from 0.5 to 33.1 mcg. In studies evaluating the transmission-blocking activity of tafenoquine against the sporogonic stage of P. vivax, it was showed a reduced transmission at doses higher than 25 mg/kg. In clinical trials, it was reported a tafenoquine-induced relapse prevention of 91.9% in cases of vivax malaria when pretreated with chloroquine. In prophylactic studies, tafenoquine showed an efficacy range from 84 to 87% against falciparum malaria and 99.1% against vivax malaria. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of tafenoquine is not well established but studies have reported a longer and more effective action when compared to primaquine. The active moiety of tafenoquine, 5,6 ortho quinone tafenoquine, seems to be redox cycled by P. falciparum which are upregulated in gametocytes and liver stages. Once inside, the oxidated metabolite produces hydrogen peroxide and hydroxyl radicals. It is thought that these radicals produce leads to the parasite death. On the other hand, tafenoquine inhibits heme polymerase in blood stage of parasites which explains the activity against blood stages of parasites. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The first-in-human pharmacokinetic study showed a tmax of 13.8 hours and this study suggested that the prolonged absorption from the gut can be due to absorption in the distal gastrointestinal tract combined with a slow clearance. The AUC and Cmax demonstrated an intersubject variability. The bioavailability of tafenoquine is increased in the presence of a high-fat meal by modifying the amount of drug absorbed rather than the rate of absorption. Once absorbed, the concentration of tafenoquine in the whole body is two-fold higher than the corresponding concentration in plasma and it seems to be highly distributed in the liver showing an AUC of approximately 80 times more than what is found in the plasma. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Tafenoquine presents a high volume of distribution of approximately 2 560 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of tafenoquine in humans is very high and it represents about 99.5%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The activation of tafenoquine needs the activity of CYP 2D6 liver microsomal enzyme. This activation step produces the metabolite 5,6 ortho quinone tafenoquine. This metabolite is internalized by the parasite and reduced to radicals by ferredoxin-NADP+ reductase and diflavin reductase enzymes. In the human, tafenoquine is metabolized by several metabolic pathways including O-demethylation, N-dealkylation, N-oxidation and oxidative deamination as well as C-hydroxylation of the 8-aminoalkylamino side chain. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After degradation by different metabolic pathways, tafenoquine is slowly excreted from the body primarily in the feces and renal elimination of the unchanged form is very low. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Tafenoquine presents a long half-life of approximately 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Tafenoquine presents a low clearance of approximately 6 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Tafenoquine can cause hemolysis in people with glucose-6-phosphate dehydrogenase deficiency. In preclinical studies, renal cell adenomas and carcinomas are increased in male rats with an overdose administration. However, this drug does not seem to be carcinogenic in humans and it was shown to lack mutagenic potential. In fertility studies, tafenoquine resulted in a reduced number of viable fetuses, implantation sites and corpora lutea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arakoda, Krintafel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tafenoquine is an antiparasitic agent used for the treatment and prevention of relapse of Vivax malaria. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Tamoxifen interact?

•Drug A: Abatacept •Drug B: Tamoxifen •Severity: MAJOR •Description: The metabolism of Tamoxifen can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tamoxifen is indicated to treat estrogen receptor positive metastatic breast cancer in adults, as an adjuvant in the treatment of early stage estrogen receptor positive breast cancer in adults, to reduce the risk of invasive breast cancer after surgery and radiation in adult women with ductal carcinoma in situ. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tamoxifen is a selective estrogen receptor modulator that inhibits growth and promotes apoptosis in estrogen receptor positive tumors. It has a long duration of action as the active metabolite N-desmethyltamoxifen has a half life of approximately 2 weeks. It has a narrow therapeutic index as higher doses can lead to breathing difficulty or convulsions. Tamoxifen administration is also associated with an increased incidence of uterine malignancies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tamoxifen competitively inhibits estrogen binding to its receptor, which is critical for it's activity in breast cancer cells. Tamoxifen leads to a decrease in tumor growth factor α and insulin-like growth factor 1, and an increase in sex hormone binding globulin. The increase in sex hormon binding globulin limits the amount of freely available estradiol. These changes reduce levels of factors that stimulate tumor growth. Tamoxifen has also been shown to induce apoptosis in estrogen receptor positive cells. This action is thought to be the result of inhibition of protein kinase C, which prevents DNA synthesis. Alternate theories for the apoptotic effect of tamoxifen comes from the approximately 3 fold increase in intracellular and mitochondrial calcium ion levels after administration or the induction of tumor growth factor β. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): An oral dose of 20mg reaches a C max of 40ng/mL with a T max of 5 hours. The metabolite N-desmethyltamoxifen reaches a C max of 15ng/mL. 10mg of tamoxifen orally twice daily for 3 months results in a C ss of 120ng/mL and a C ss of 336ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of tamoxifen is approximately 50-60L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of tamoxifen in plasma is over 98% and mostly to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tamoxifen can by hydroxylated to α-hydroxytamoxifen which is then glucuronidated or undergoes sulfate conjugation by sulfotransferase 2A1. Tamoxifen can also undergo N-oxidation by flavin monooxygenases 1 and 3 to tamoxifen N-oxide. Tamoxifen is N-dealkylated to N-desmethyltamoxifen by CYP2D6, CYP1A1, CYP1A2, CYP3A4, CYP1B1, CYP2C9, CYP2C19, and CYP3A5. N-desmethyltamoxifen can be sulfate conjugated to form N-desmethyltamoxifen sulfate, 4-hydroxylated by CYP2D6 to form endoxifen, or N-dealkylated again by CYP3A4 and CYP3A5 to N,N-didesmethyltamoxifen. N,N-didesmethyltamoxifen undergoes a substitution reaction to form tamoxifen metabolite Y, followed by ether cleavage to metabolite E, which can then be sulfate conjugated by sulfotransferase 1A1 and 1E1 or O-glucuronidated. Tamoxifen can also by 4-hydroxylated by CYP2D6, CYP2B6, CYP3A4, CYP2C9, and CYP2C19 to form 4-hydroxytamoxifen. 4-hydroxytamoxifen can undergo glucuronidation by UGT1A8, UGT1A10, UGT2B7, and UGT2B17 to tamoxifen glucuronides, sulfate conjugation by sulfotransferase 1A1 and 1E1 to 4-hydroxytamoxifen sulfate, or N-dealkylation by CYP3A4 and CYP3A5 to endoxifen. Endoxifen undergoes demethylation to norendoxifen, a reversible sulfate conjugation reaction via sulfotransferase 1A1 and 1E1 to 4-hydroxytamoxifen sulfate, sulfate conjugation via sulfotransferase 2A1 to 4-endoxifen sulfate, or glucuronidation via UGT1A8, UGT1A10, UGT2B7, or UGT2B15 to tamoxifen glucuronides. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tamoxifen is mainly eliminated in the feces. Animal studies have shown 75% of radiolabelled tamoxifen recovered in the feces, with negligible collection from urine. However, 1 human study showed 26.7% recovery in the urine and 24.7% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of tamoxifen is 5 to 7 days, while the half-life of N-desmethyltamoxifen, the primary circulating metabolite, is approximately 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of tamoxifen was 189mL/min in a study of six postmenopausal women. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): High doses of tamoxifen in animals lead to respiratory difficulty and convulsions. High doses in advanced metastatic cancer patients resulted in acute neurotoxicity seen by tremor, hyperreflexia, unsteady gait, and dizziness. Patients experiencing and overdose should be given supportive treatment as no specific treatment for overdose is suggested. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Soltamox •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tamoxifen Tamoxifène Tamoxifene Tamoxifeno Tamoxifenum trans-Tamoxifen •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tamoxifen is a selective estrogen receptor modulator used to treat estrogen receptor positive breast cancer, reduce the risk of invasive breast cancer following surgery, or reduce the risk of breast cancer in high risk women.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Tamoxifen interact? Information: •Drug A: Abatacept •Drug B: Tamoxifen •Severity: MAJOR •Description: The metabolism of Tamoxifen can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tamoxifen is indicated to treat estrogen receptor positive metastatic breast cancer in adults, as an adjuvant in the treatment of early stage estrogen receptor positive breast cancer in adults, to reduce the risk of invasive breast cancer after surgery and radiation in adult women with ductal carcinoma in situ. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tamoxifen is a selective estrogen receptor modulator that inhibits growth and promotes apoptosis in estrogen receptor positive tumors. It has a long duration of action as the active metabolite N-desmethyltamoxifen has a half life of approximately 2 weeks. It has a narrow therapeutic index as higher doses can lead to breathing difficulty or convulsions. Tamoxifen administration is also associated with an increased incidence of uterine malignancies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tamoxifen competitively inhibits estrogen binding to its receptor, which is critical for it's activity in breast cancer cells. Tamoxifen leads to a decrease in tumor growth factor α and insulin-like growth factor 1, and an increase in sex hormone binding globulin. The increase in sex hormon binding globulin limits the amount of freely available estradiol. These changes reduce levels of factors that stimulate tumor growth. Tamoxifen has also been shown to induce apoptosis in estrogen receptor positive cells. This action is thought to be the result of inhibition of protein kinase C, which prevents DNA synthesis. Alternate theories for the apoptotic effect of tamoxifen comes from the approximately 3 fold increase in intracellular and mitochondrial calcium ion levels after administration or the induction of tumor growth factor β. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): An oral dose of 20mg reaches a C max of 40ng/mL with a T max of 5 hours. The metabolite N-desmethyltamoxifen reaches a C max of 15ng/mL. 10mg of tamoxifen orally twice daily for 3 months results in a C ss of 120ng/mL and a C ss of 336ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of tamoxifen is approximately 50-60L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of tamoxifen in plasma is over 98% and mostly to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tamoxifen can by hydroxylated to α-hydroxytamoxifen which is then glucuronidated or undergoes sulfate conjugation by sulfotransferase 2A1. Tamoxifen can also undergo N-oxidation by flavin monooxygenases 1 and 3 to tamoxifen N-oxide. Tamoxifen is N-dealkylated to N-desmethyltamoxifen by CYP2D6, CYP1A1, CYP1A2, CYP3A4, CYP1B1, CYP2C9, CYP2C19, and CYP3A5. N-desmethyltamoxifen can be sulfate conjugated to form N-desmethyltamoxifen sulfate, 4-hydroxylated by CYP2D6 to form endoxifen, or N-dealkylated again by CYP3A4 and CYP3A5 to N,N-didesmethyltamoxifen. N,N-didesmethyltamoxifen undergoes a substitution reaction to form tamoxifen metabolite Y, followed by ether cleavage to metabolite E, which can then be sulfate conjugated by sulfotransferase 1A1 and 1E1 or O-glucuronidated. Tamoxifen can also by 4-hydroxylated by CYP2D6, CYP2B6, CYP3A4, CYP2C9, and CYP2C19 to form 4-hydroxytamoxifen. 4-hydroxytamoxifen can undergo glucuronidation by UGT1A8, UGT1A10, UGT2B7, and UGT2B17 to tamoxifen glucuronides, sulfate conjugation by sulfotransferase 1A1 and 1E1 to 4-hydroxytamoxifen sulfate, or N-dealkylation by CYP3A4 and CYP3A5 to endoxifen. Endoxifen undergoes demethylation to norendoxifen, a reversible sulfate conjugation reaction via sulfotransferase 1A1 and 1E1 to 4-hydroxytamoxifen sulfate, sulfate conjugation via sulfotransferase 2A1 to 4-endoxifen sulfate, or glucuronidation via UGT1A8, UGT1A10, UGT2B7, or UGT2B15 to tamoxifen glucuronides. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tamoxifen is mainly eliminated in the feces. Animal studies have shown 75% of radiolabelled tamoxifen recovered in the feces, with negligible collection from urine. However, 1 human study showed 26.7% recovery in the urine and 24.7% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of tamoxifen is 5 to 7 days, while the half-life of N-desmethyltamoxifen, the primary circulating metabolite, is approximately 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of tamoxifen was 189mL/min in a study of six postmenopausal women. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): High doses of tamoxifen in animals lead to respiratory difficulty and convulsions. High doses in advanced metastatic cancer patients resulted in acute neurotoxicity seen by tremor, hyperreflexia, unsteady gait, and dizziness. Patients experiencing and overdose should be given supportive treatment as no specific treatment for overdose is suggested. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Soltamox •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tamoxifen Tamoxifène Tamoxifene Tamoxifeno Tamoxifenum trans-Tamoxifen •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tamoxifen is a selective estrogen receptor modulator used to treat estrogen receptor positive breast cancer, reduce the risk of invasive breast cancer following surgery, or reduce the risk of breast cancer in high risk women. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Tamsulosin interact?

•Drug A: Abatacept •Drug B: Tamsulosin •Severity: MODERATE •Description: The metabolism of Tamsulosin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tamsulosin is indicated for the treatment of signs and symptoms of benign prostatic hyperplasia. Tamsulosin is also used off label for the treatment of ureteral stones, prostatitis, and female voiding dysfunction. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tamsulosin is an alpha adrenoceptor blocker with specificity for the alpha-1A and alpha-1D subtypes, which are more common in the prostate and submaxillary tissue. The final subtype, alpha-1B, are most common in the aorta and spleen. Tamsulosin binds to alpha-1A receptors 3.9-38 times more selectively than alpha-1B and 3-20 times more selectively than alpha-1D. This selectivity allows for a significant effect on urinary flow with a reduced incidence of adverse reactions like orthostatic hypotension. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tamsulosin is a blocker of alpha-1A and alpha-1D adrenoceptors. About 70% of the alpha-1 adrenoceptors in the prostate are of the alpha-1A subtype. By blocking these adrenoceptors, smooth muscle in the prostate is relaxed and urinary flow is improved. The blocking of alpha-1D adrenoceptors relaxes the detrusor muscles of the bladder which prevents storage symptoms. The specificity of tamsulosin focuses the effects to the target area while minimizing effects in other areas. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral tamsulosin is 90% absorbed in fasted patients. The area under the curve is 151-199ng/mL*hr for a 0.4mg oral dose and 440-557ng/mL*hr for a 0.8mg oral dose. The maximum plasma concentration is 3.1-5.3ng/mL for a 0.4mg oral dose and 2.5-3.6ng/mL for a 0.8mg oral dose. Taking tamsulosin with food increases the time to maximum concentration from 4-5 hours to 6-7 hours but increases bioavailability by 30% and maximum plasma concentration by 40-70%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 16L after intravenous administration. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tamsulosin is 94%-99% protein bound, mostly to alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tamsulosin is mostly metabolized in the liver by cytochrome P450 (CYP) 3A4 and 2D6, with some metabolism by other CYPs. CYP3A4 is responsible for the deethylation of tamsulosin to the M-1 metabolite and the oxidative deamination to the AM-1 metabolite, while CYP2D6 is responsible for the hydroxylation of tamsulosin to the M-3 metabolite and the demethylation of tamsulosin to the M-4 metabolite. In addition, tamsulosin can be hydroxylated at a different position by an unknown enzyme to form the M-2 metabolite. The M-1, M-2, M-3, and M-4 metabolites can be glucuronidated, and the M-1 and M-3 metabolites can undergo sulfate conjugation to form other metabolites before excretion. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 97% of an orally administered does is recovered in studies, which 76% in the urine and 21% in the feces after 168 hours. 8.7% of the dose is excreted as unmetabolized tamsulosin. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life in fasted patients is 14.9±3.9 hours. The elimination half life is 5-7 hours and the apparent half life is 9 to 13 hours in healthy subjects. In patients who require tamsulosin, the apparent half life is 14-15 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 2.88L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of overdose, patients may experience hypotension and should lie down in a supine position to maintain blood pressure and heart rate. If further measures are required intravenous fluids should be considered. If further progression is required, vasopressors may be used and renal function should be monitored. Dialysis is unlikely to assist in treating overdose because tamsulosin is extensively protein bound. The oral LD50 in rats is 650mg/kg. Tamsulosin is not indicated for use in women and no studies have been performed in pregnancy, though animal studies have not shown fetal harm. Tamsulosin is excreted in the milk of rats but there is no available data on what the effect of this tamsulosin exposure may be. Animal studies have shown male and female rat fertility is affected by tamsulosin due to impairment of ejaculation and fertilization. In men, tamsulosin is associated with abnormal ejaculation. Tamsulosin is not mutagenic but may be carcinogenic at levels above the maximum recommended human dose. Female rats experience a slight increase in the rates of mammary gland fibroadenomas and adenocarcinomas. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Flomax, Jalyn •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tamsulosin Tamsulosina Tamsulosine Tamsulosinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tamsulosin is an alpha-1A and alpha-1B adrenergic receptor antagonist used to treat benign prostatic hyperplasia, ureteral stones, prostatitis, and female voiding dysfunction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tamsulosin interact? Information: •Drug A: Abatacept •Drug B: Tamsulosin •Severity: MODERATE •Description: The metabolism of Tamsulosin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Tamsulosin is indicated for the treatment of signs and symptoms of benign prostatic hyperplasia. Tamsulosin is also used off label for the treatment of ureteral stones, prostatitis, and female voiding dysfunction. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Tamsulosin is an alpha adrenoceptor blocker with specificity for the alpha-1A and alpha-1D subtypes, which are more common in the prostate and submaxillary tissue. The final subtype, alpha-1B, are most common in the aorta and spleen. Tamsulosin binds to alpha-1A receptors 3.9-38 times more selectively than alpha-1B and 3-20 times more selectively than alpha-1D. This selectivity allows for a significant effect on urinary flow with a reduced incidence of adverse reactions like orthostatic hypotension. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tamsulosin is a blocker of alpha-1A and alpha-1D adrenoceptors. About 70% of the alpha-1 adrenoceptors in the prostate are of the alpha-1A subtype. By blocking these adrenoceptors, smooth muscle in the prostate is relaxed and urinary flow is improved. The blocking of alpha-1D adrenoceptors relaxes the detrusor muscles of the bladder which prevents storage symptoms. The specificity of tamsulosin focuses the effects to the target area while minimizing effects in other areas. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral tamsulosin is 90% absorbed in fasted patients. The area under the curve is 151-199ng/mL*hr for a 0.4mg oral dose and 440-557ng/mL*hr for a 0.8mg oral dose. The maximum plasma concentration is 3.1-5.3ng/mL for a 0.4mg oral dose and 2.5-3.6ng/mL for a 0.8mg oral dose. Taking tamsulosin with food increases the time to maximum concentration from 4-5 hours to 6-7 hours but increases bioavailability by 30% and maximum plasma concentration by 40-70%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 16L after intravenous administration. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tamsulosin is 94%-99% protein bound, mostly to alpha-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tamsulosin is mostly metabolized in the liver by cytochrome P450 (CYP) 3A4 and 2D6, with some metabolism by other CYPs. CYP3A4 is responsible for the deethylation of tamsulosin to the M-1 metabolite and the oxidative deamination to the AM-1 metabolite, while CYP2D6 is responsible for the hydroxylation of tamsulosin to the M-3 metabolite and the demethylation of tamsulosin to the M-4 metabolite. In addition, tamsulosin can be hydroxylated at a different position by an unknown enzyme to form the M-2 metabolite. The M-1, M-2, M-3, and M-4 metabolites can be glucuronidated, and the M-1 and M-3 metabolites can undergo sulfate conjugation to form other metabolites before excretion. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 97% of an orally administered does is recovered in studies, which 76% in the urine and 21% in the feces after 168 hours. 8.7% of the dose is excreted as unmetabolized tamsulosin. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life in fasted patients is 14.9±3.9 hours. The elimination half life is 5-7 hours and the apparent half life is 9 to 13 hours in healthy subjects. In patients who require tamsulosin, the apparent half life is 14-15 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 2.88L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): In the event of overdose, patients may experience hypotension and should lie down in a supine position to maintain blood pressure and heart rate. If further measures are required intravenous fluids should be considered. If further progression is required, vasopressors may be used and renal function should be monitored. Dialysis is unlikely to assist in treating overdose because tamsulosin is extensively protein bound. The oral LD50 in rats is 650mg/kg. Tamsulosin is not indicated for use in women and no studies have been performed in pregnancy, though animal studies have not shown fetal harm. Tamsulosin is excreted in the milk of rats but there is no available data on what the effect of this tamsulosin exposure may be. Animal studies have shown male and female rat fertility is affected by tamsulosin due to impairment of ejaculation and fertilization. In men, tamsulosin is associated with abnormal ejaculation. Tamsulosin is not mutagenic but may be carcinogenic at levels above the maximum recommended human dose. Female rats experience a slight increase in the rates of mammary gland fibroadenomas and adenocarcinomas. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Flomax, Jalyn •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tamsulosin Tamsulosina Tamsulosine Tamsulosinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Tamsulosin is an alpha-1A and alpha-1B adrenergic receptor antagonist used to treat benign prostatic hyperplasia, ureteral stones, prostatitis, and female voiding dysfunction. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.