Calcium Antagonists in Intensive Care

Abstract

In 1963, Fleckenstein observed that two newly synthetized vasodilators mimicked the effect of calcium ion withdrawal. Both inhibited the excitation-contraction coupling, diminishing the contractile force of cardiac muscle without a major change in the action potential. Several years later Fleckenstein and his colleagues demonstrated that verapamil and nifidipine selectively depress the slow transmembrane Ca^{+ +} current [15]. Of the many agents which inhibit the slow inward current, verapamil, nifedipine and diltiazem are the drugs most widely used. A striking feature of the calcium antagonist is their chemical heterogeneity, which suggests that they act at different receptor sites.