- Subject has taken enzyme-modifying drugs that are moderate inhibitors/potent inducers of cytochrome P450 3A4 or potent inhibitors of cytochrome P450 2C19 enzymes (such as cimetidine, quinidine, erythromycin, ciprofloxacin, fluconazole, ketoconazole etc…) and strong inducers of CYP enzymes (such as rifampin etc…), in the previous 28 days before day 0.