Bioavailability may be increased resulting in increased BP lowering effects w/ grapefruit juice. Increased exposure to simvastatin. Plasma conc may be increased w/ strong or moderate CYP3A4 inhibitors eg, PIs (eg, ritonavir), azole antifungals (eg, ketoconazole, itraconazole), macrolides (eg, erythromycin, clarithromycin), verapamil or diltiazem. Plasma conc may be lowered w/ CYP3A4 inducers eg, rifampicin, St. John's wort. Increased trough levels of ciclosporin. May increase blood levels of tacrolimus.