Plasma conc may be increased by strong CYP3A inhibitors, including but not limited to certain antivirals (eg, indinavir, nelfinavir, ritonavir, saquinavir), macrolide antibiotics (eg, clarithromycin, telithromycin, troleandomycin), antifungals (eg, itraconazole, ketoconazole, posaconazole, voriconazole), & nefazodone; grapefruit or grapefruit juice. Plasma conc may be decreased by strong CYP3A inducers, including but not limited to rifampin, carbamazepine, phenytoin, rifabutin, phenobarb & St. John's Wort; moderate CYP3A inducers, including but not limited to efavirenz, modafinil, bosentan, etravirine & nafcillin. May reduce plasma conc & effectiveness of CYP3A substrates w/ narrow therapeutic index (eg, alfentanil, fentanyl, quinidine, cyclosporine, sirolimus, tacrolimus). May induce other enzymes & transporters (eg, CYP2C, P-gp) via the same mechanisms responsible for CYP3A induction (eg, pregnane X receptor activation). May increase plasma conc of substrates of P-gp (eg, digoxin, dabigatran, colchicine, pravastatin), BCRP (eg, methotrexate, rosuvastatin, sulfasalazine), OCT1, MATE1, & MATE2K.