In vitro, faldaprevir inhibited key processes involved in bilirubin clearance: UDP glucuronosyltransferase (UGT) 1A1 (UGT1A1) (IC50 0.45 µM), which conjugates bilirubin, and hepatic uptake and efflux transporters, organic anion-transporting polypeptide (OATP) 1B1 (IC50 0.57 µM), OATP1B3 (IC50 0.18 µM), and multidrug resistance-associated protein (MRP) 2 (IC50 6.2 µM), which transport bilirubin and its conjugates