About Verapamil Calcium channel blocker, phenylalkylamine derivative, Class IV Antiarrhythmic, antihypertensive. Mechanism of Action of Verapamil Verapamil is a phenylalkylamine- Ca channel blocker. It exerts it`s antianginal, antihypertensive, antiarrythmic 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, and decrease BP in hypertensive individuals. It increase exercise tolerance and reduce myocardial oxygen demand in angina patients. It acts as a coronary artery dilator inhibits coronary artery spasm and improves coronary blood flow and myocardial oxygen supply. It decreases after load and cardiac work. It prevents conduction and development of action potentials in heart. It suppresses automaticity. e