Calcium Blocking Drugs for Angina Pectoris

The introduction of the calcium channel blockers for the treatment of angina pectoris has been heralded as the most significant medical event in cardiology since the introduction of the beta adrenergic receptor blocking drugs (1-5). Calcium blockers, sometimes called calcium antagonists or slow channel blockers, have as their primary mechanism of action the ability to reduce intracellular calcium ion (Ca2+) concentration in cardiac and vascular smooth muscle (6-10). In studies of isolated tissue, the drugs exert negative chronotropic, dromotropic, and inotropic effects on the heart and relax vascular smooth muscle. This latter property has generated the present intense interest in these drugs since it is now recognized that coro­ nary vasospasm may play a major role in a significant minority of patients with ischemic heart disease (11-18). In this paper we review the clinical picture of coronary vasospasm, the pharmacology of the major calcium blockers, and the use of these drugs in the treatment of Prinzmetal's or variant angina and chronic stable angina pectoris.