- Use of strong CYP1A2 or 3A4 inducers and/or inhibitors (for example, but not limited to, ketoconazole, rifampicin, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, troleandomycin (TAO), voriconazole, grapefruit or grapefruit juice, rifabutin, rifapentine, phenytoin, carbamazepine, phenobarbital and St. John's Wort) is not permitted while on study or within 7 days prior to study enrollment