Drug Interaction Report

MONITOR: Coadministration with maralixibat may decrease the plasma concentrations of drugs that are substrates of organic anion transporting polypeptide 2B1 (OATP2B1), such as statin drugs. Maralixibat is an inhibitor of the OATP2B1 transporter in vitro. A decrease in the oral absorption of drugs that rely on OATP2B1-mediated uptake in the gastrointestinal tract may occur when administered with maralixibat. In clinical studies, coadministration of maralixibat (4.75 mg once daily in the morning) with daily evening doses of simvastatin, lovastatin, or atorvastatin did not result in clinically relevant effects on the pharmacokinetics of these statin drugs or their metabolites. However, the effect of maralixibat on the pharmacokinetics of OATP2B1substrate drugs at higher daily doses, such as the maximum recommended daily dose of 28.5 mg (for body weight of 70 kg or more), has not been evaluated in clinical studies.

MANAGEMENT: Until more information is available, caution is advised if maralixibat is used concomitantly with drugs that are substrates of OATP2B1. Dosage adjustments as well as clinical and laboratory monitoring of OATP2B1 substrate drugs may be appropriate whenever maralixibat is added to or withdrawn from therapy.