3.1.16 Patient must have discontinued use of the following drugs which are an inducers or inhibitors of CYP3A4 at least 2 days prior to registration: ethinylestradiol, gestodene, itraconazole, ketoconazole, cimetidine, erythromycin, carbamazepine, high dose chronic steroids, phenobarbital, phenytoin, rifampin (rifampcin), and sulfinpyrazone.