- Food or drugs that are known to be CYP3A4 inhibitors (e.g. grapefruit juice, verapamil, ketoconazole, miconazole, itraconazole, erythromycin, clarithromycin, telithromycin, indinavir, ritonavir, nelfinavir, atazanavir, amprenavir, nefazodone, diltiazem, and delavirdine) or inducers (i.e. dexamethasone, glucocorticoids, progesterone, rifampin, phenobarbital, St. John's wort).