Increased exposure of simvastatin. Increased bioavailability w/ grapefruit or grapefruit juice. CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir) may increase plasma conc of amlodipine. Increased risk of hypotension w/ clarithromycin. May decrease plasma conc of amlodipine w/ CYP3A4 inducers (eg, rifampicin, Hypericum perforatum
). Cyclosporine, tacrolimus. Amlodipine may increase exposure of mTOR inhibitors.