Calcium channel blocking drugs. Part II: Clinical applications.

CCB are a diverse group of drugs that bind to specific glycoprotein receptors associated with the cell membrane that are most likely identical to the voltage-sensitive calcium channel. By inhibiting the influx of calcium into myocardial, pacemaker, and conducting tissues and vascular smooth muscle, these agents modify excitation-contraction coupling in muscle and electrical impulse transmission in the heart. The vasodilating and electrophysiologic actions of these drugs have been harnessed for the treatment of coronary vasospasm, angina pectoris, and supraventricular arrhythmias. They also have great potential for the treatment of hypertension, cerebrovascular disorders, and Raynaud's phenomenon. Their utility in hypertrophic cardiomyopathy, congestive heart failure, myocardial preservation, and primary pulmonary hypertension has not been convincingly established. Future second-generation CCB may offer greater selectivity, improved side effect profiles, and an even wider range of actions.