Drug Interaction Report

Coadministration with inhibitors of CYP450 3A4 may increase the plasma concentrations of atogepant, which is primarily metabolized by the isoenzyme. When atogepant was administered with the potent CYP450 3A4 inhibitor itraconazole in healthy study subjects, atogepant peak plasma concentration (Cmax) and systemic exposure (AUC) increased by approximately 2.2- and 5.5-fold, respectively. However, moderate and weak inhibitors may interact to a much lesser extent. Population pharmacokinetic modeling has suggested that moderate (e.g., cyclosporine, ciprofloxacin, fluconazole, fluvoxamine, grapefruit juice) or weak (e.g., cimetidine, esomeprazole) CYP450 3A4 inhibitors may increase atogepant AUC by 1.7- and 1.1-fold, respectively. The changes in atogepant exposure when coadministered with moderate or weak CYP450 3A4 inhibitors are not expected to be clinically significant.

GENERALLY AVOID: Grapefruit and grapefruit juice may significantly increase the plasma concentrations of orally administered ranolazine. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because ranolazine prolongs QT interval in a dose-dependent manner, high plasma levels of ranolazine may increase the risk of ventricular arrhythmias such as ventricular tachycardia, ventricular fibrillation, and torsade de pointes.

MANAGEMENT: Patients treated with ranolazine should avoid consumption of grapefruit juice and other grapefruit products if possible. Otherwise, the dosage of ranolazine should be limited to 500 mg twice a day.