 - g. CYP3A4 inducers: Patients must also avoid strong inducers of CYP3A4 and may not have received these medications within 1 week of entry. These include: Anticonvulsants: carbamazepine, phenobarbital, phenytoin; Antibiotics: rifabutin, rifapentine; Herbal preparations: St. Johns wort Hypericum perforatum, hypericine. 