Drug Interaction Report

Theoretically, coadministration with inducers of CYP450 3A4 and/or P-glycoprotein (P-gp) may decrease the plasma concentrations of rivaroxaban, which is a substrate of the isoenzyme as well as the efflux transporter. In a pharmacokinetic study, administration of a single 20 mg dose of rivaroxaban with the potent CYP450 3A4 and P-gp inducer rifampin (titrated up to 600 mg once daily) resulted in approximately 22% and 50% decreases in mean rivaroxaban peak plasma concentration (Cmax) and system exposure (AUC), respectively, with parallel decreases in its pharmacodynamic effects. The effects of less potent inducers of either CYP450 3A4 or P-gp have not been studied.

MONITOR: Isolated case reports have suggested that the ingestion of alcohol during griseofulvin therapy may rarely cause disulfiram-like reactions, flushing, tachycardia, or increased effects of alcohol. The mechanism is unknown.

MANAGEMENT: Patients should be advised of the possibility of increased adverse effects or a disulfiram-like reaction.