Increased conc w/ strong CYP3A4 inhibitors eg, ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, voriconazole. Concomitant use w/ moderate CYP3A inhibitors. Decreased conc w/ strong CYP3A4 inducers eg, phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarb.