Diltiazem hydrochloride is a calcium channel antagonist. It is a peripheral and coronary vasodilator with some negative inotropic activity. Diltiazem inhibits cardiac conduction particularly at the sino-atrial and atrioventricular nodes. Diltiazem has the following actions:
Antianginal: A direct dilatation of coronary arteries and arterioles proved oxygen supply to myocardial tissues. In addition dilatation of the peripheral vasculature reduces systemic pressure of cardiac “after load” which results in lessened stress and reduced oxygen requirements of the myocardial tissues.
Antiarrhythmic: The inhibited influx of calcium ions in cardiac tissues result in slowed electrophysiological activity through the S-A and A-V nodes without affecting accessory bypass conduction or altering normal atrial action potential or intraventricular conduction.
Antihypertensive: Reduces peripheral vascular resistance as a result of vasodilatation.