Decreased plasma levels w/ CYP3A4 inducers (eg, carbamazepine, phenytoin, phenobarb, rifampicin, St. John's wort). Increased plasma levels w/ CYP3A4 inhibitors (eg, itraconazole, ketoconazole, erythromycin, HIV PIs, grapefruit juice, cyclosporin, cimetidine). May increase tacrolimus conc.