Drug Interaction Report

MONITOR: Coadministration with moderate inducers of CYP450 3A4 may decrease the plasma concentrations of maribavir, which is primarily metabolized by the isoenzyme. When maribavir (400 mg twice daily) was administered with the potent CYP450 3A4 inducer, rifampin (600 mg once daily), maribavir peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 39% and 60%, respectively. The interaction has not been studied with other, less potent inducers.

MANAGEMENT: The potential for diminished pharmacologic effects of maribavir should be considered during coadministration with moderate CYP450 3A4 inducers. Alternative treatments may be required if an interaction is suspected. If coadministration with moderate CYP450 3A inducers cannot be avoided, a dosage increase of maribavir up to 1,200 mg twice daily has been suggested by some authorities.