- CYP3A4 inducers: patients chronically receiving drugs that are known potent CYP3A4 inducers within 12 days prior to study enrollment, including but not limited to carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, ritonavir, and St. John's wort are not eligible; the topical use of these medications (if applicable) is allowed