Avoid co-administration w/ CYP3A4 inhibitors eg, ketoconazole, itraconazole, ritonavir, erythromycin, troleandomycin, clarithromycin.
Increased cyclosporin, simvastatin AUC. Increased hypotensive effect w/ grapefruit or grapefruit juice, high-dose cimetidine, other BP-affecting drugs eg, α-blockers, TCAs, neuroleptics. Reduced antihypertensive effect w/ CYP3A4 inducers ie, anticonvulsants (eg, phenytoin, phenobarb, carbamazepine), rifampicin. Potentiated effect w/ alcohol. Increased absorption w/ midazolam. Reduced bioavailability w/ metoprolol. Increased digoxin C
max. Reduced hypotensive effect w/ corticosteroids. Caution w/ other CYP3A4 substrates ie, terfenadine, astemizole, class III antiarrhythmics eg, amiodarone, quinidine, sotalol.