- Participants taking a known significant CYP 3A4 inducer or inhibitor; known significant inducers/inhibitors include: amprenavir, aprepitant, atazanavir, carbamazepine, clarithromycin, conivaptan, diltiazem, darunavir/ritonavir, dronedarone, erythromycin, fluconazole, fosamprenavir, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, phenytoin, posaconazole, rifampin, ritonavir, St. John's wort, saquinavir, telithromycin, tipranavir/ritonavir, verapamil, voriconazole