Risperidone and Ritonavir interaction

WARNING: DRUG-DRUG INTERACTIONS LEADING TO POTENTIALLY SERIOUS AND/OR LIFE THREATENING REACTIONS Co-administration of NORVIR with several classes of drugs including sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse events due to possible effects of NORVIR on the hepatic metabolism…

…POTENTIALLY SERIOUS AND/OR LIFE THREATENING REACTIONS See full prescribing information for complete boxed warning Co-administration of NORVIR with several classes of drugs including sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations may result in potentially serious and/or life-threatening adverse events due to possible effects of NORVIR on the…

…Antagonist: alfuzosin ○ Antianginal: ranolazine ○ Antiarrhythmics: amiodarone, dronedarone, flecainide, propafenone, quinidine ○ Antifungal: voriconazole ○ Anti-gout: colchicine ○ Antipsychotics: lurasidone, pimozide ○ Ergot Derivatives: dihydroergotamine, ergotamine, methylergonovine ○ GI Motility Agent: cisapride ○ HMG-CoA Reductase Inhibitors: lovastatin,…

Antipsychotics: lurasidone pimozide ↑ lurasidone ↑ pimozide Contraindicated due to potential for serious and/or life-threatening reactions [see Contraindications ( 4 ) ] .

Sedative/Hypnotics: triazolam, orally administered midazolam ↑ triazolam ↑ midazolam Contraindicated due to potential for prolonged or increased sedation or respiratory depression [see Contraindications ( 4 ) ] .

Carbamazepine and other enzyme inducers decrease plasma concentrations of risperidone.

Fluoxetine and Paroxetine Fluoxetine (20 mg once daily) and paroxetine (20 mg once daily), CYP 2D6 inhibitors, have been shown to increase the plasma concentration of risperidone 2.5–2.8 fold and 3–9 fold respectively.

Carbamazepine and Other CYP 3A4 Enzyme Inducers Carbamazepine co-administration with oral RISPERDAL decreased the steady-state plasma concentrations of risperidone and 9-hydroxyrisperidone by about 50%.

Co-administration of other known CYP 3A4 enzyme inducers (e.g., phenytoin, rifampin, and phenobarbital) with risperidone may cause similar decreases in the combined plasma concentrations of risperidone and 9-hydroxyrisperidone, which could lead to decreased efficacy of RISPERDAL CONSTA treatment.

At the initiation of therapy with carbamazepine or other known hepatic enzyme inducers, patients should be closely monitored during the first 4–8 weeks, since the dose of RISPERDAL CONSTA may need to be adjusted.