Mechanism of action of amlodipineamlodipine is a second generation dihydropyridine ca channel blocker. it exerts it`s antihypertensive, antianginal actions through blocking the influx of ca ions through voltage gated l-type ca channels to the peripheral vascular smooth muscle cells, coronary smooth muscle cells and to the myocardial cells. thus causes dilatation of vascular endothelium, decrease peripheral resistance, & reduce myocardial oxygen demand .it markedly relax arterioles and milder effects on veins. they do not compromise haemodynamics and cerebral and renal perfusion.mechanism of action benazeprilat, the active metabolite of benazepril, competes with angiotensin i for binding at the angiotensin-converting enzyme, blocking the conversion of angiotensin i to angiotensin ii. inhibition of ace results in decreased plasma angiotensin ii. as angiotensin ii is a vasoconstrictor and a negative-feedback mediator for renin activity, lower concentrations result in a decrease in blo