Increased antihypertensive effect w/ baclofen; nitroglycerin & other nitrates or other vasodilators; α-blockers; amifostine; TCAs, antipsychotics, anaesth. Reduced antihypertensive effect w/ corticosteroids, tetracosactide. Perindopril: Higher frequency of adverse events w/ other ACE inhibitors, angiotensin II receptor blockers or aliskiren. Increased occurrence of hyperkalaemia w/ aliskiren, K salts, K-sparing diuretics, other ACE inhibitors, angiotensin II receptor antagonists, NSAIDs, heparin, immunosuppressants; co-trimoxazole. Risk of hyperkalaemia, worsening of renal function & CV morbidity & mortality increase w/ aliskiren in diabetic or impaired renal patients. Increased risk of angioedema w/ sacubitril/valsartan; estramustine; racecadotril; mTOR inhibitors (eg, sirolimus, everolimus, temsirolimus); gliptins (eg, linagliptin, saxagliptin, sitagliptin, vildagliptin). Increased serum lithium conc & toxicity. Increased blood-glucose lowering effect of antidiabetic medicines. Increased hypotensive effect w/ non-K-sparing diuretics. Reduced antihypertensive effect w/ NSAIDs including aspirin ≥3 g/day; sympathomimetics. Nitritoid reactions w/ inj gold. Amlodipine: Avoid concomitant use w/ dantrolene infusion in patients susceptible to malignant hyperthermia & in the management of malignant hyperthermia. Reduced plasma conc w/ CYP3A4 inducers (eg, rifampicin, Hypericum perforatum
). Increased exposure w/ strong or moderate CYP3A4 inhibitors (eg, PIs, azole antifungals, macrolides like erythromycin or clarithromycin, verapamil or diltiazem). Increased hypotensive effects w/ other antihypertensives; grapefruit or grapefruit juice. Risk of increased blood levels of tacrolimus. May increase exposure of mTOR inhibitors; simvastatin. Monitor ciclosporin levels in renal transplant patients on amlodipine.