- Not currently on enzyme-inducing anti-convulsants or other strong inducers of CYP3A4 (efavirenz, nevirapine, barbiturates, carbamazepine, modafinil, phenobarbital, phenytoin, rifabutin, rifampin, pioglitazone, or St. John wort) or strong inhibitors of CYP3A4 (indinavir, nelfinavir, ritonavir, clarithromycin, itraconazole, voriconazole, ketoconazole, nefazodone, saquinavir, or telithromycin)