Drug Interaction Report

GENERALLY AVOID: Coadministration with potent or moderate inducers of CYP450 3A4 may decrease the plasma concentrations of pimavanserin, which is primarily metabolized by the isoenzyme. In a drug interaction study designed to measure pre- and post-pimavanserin levels following rifampin administration (a potent CYP450 3A4 inducer), Cmax and AUC were decreased by 71% and 91%, respectively, compared to pre-rifampin plasma concentrations. A physiologically based pharmacokinetic simulation with a moderate CYP450 3A4 inducer (efavirenz) predicted Cmax and AUC of pimavanserin will be decreased by approximately 60% and 70%, respectively.

MANAGEMENT: Coadministration of potent or moderate CYP450 3A4 inducers with pimavanserin should be avoided.