Verapamil, known as the brand names Calan, Isoptin, Tarka, and Verelan, is a non-dihydropyridine calcium channel blocker used in the treatment of angina, arrhythmia, and hypertension. It is used for the treament of vasopastic angina, unstable angina, chronic stable angina, treat hypertension, for the prophylaxis of repetitive paroxysmal supraventricular tachycardia,and atrial fibrillation or atrial flutter in combination with digoxin. It is normally given intravenously, so it has a rapid release with a short duration of action. Verapamil acts on smooth muscles and cardiac muscles. Verapamil is an L-type calcium channel blocker with antiarrhythmic, antianginal, and antihypertensive activity. The inhibition of L-type calcium channels prevents the influx of calcium in vascular smooth muscle myocytes and the heart's cardiomyocytes, which prevents contraction of vascular smooth muscles and heart muscles. Preventing the contraction of vascular smooth muscles causes relaxation or dilation of peripheral blood vessels. This reduction in vascular resistance also reduces the force on the heart, decreasing myocardial energy consumption and oxygen requirements. Verapamil's mechanism of action in the treatment of cluster headaches is unclear, but is thought to be involved with its effect on calcium channels.

Verapamil Calcium Channel Vasodilation Pathway References