Increased plasma exposure w/ CYP3A4 inhibitors (eg, boceprevir, clarithromycin, cobicistat, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, voriconazole, diltiazem, erythromycin, fluconazole, verapamil). Decreased plasma exposure w/ CYP3A4 inducers [eg, carbamazepine, phenobarb, phenytoin, rifampicin, St. John's wort (
Hypericum perforatum), bosentan, efavirenz, etravirine, modafinil, nafcillin]. Potential effect w/ P-gp substrates w/ narrow therapeutic index. Possible primary CNS effects in combination w/ other centrally acting medicinals & alcohol.