Pleiotropic action of calcium antagonists

pp. 225-232

Abstract

Calcium antagonists are a group of different drugs with a common action: they block the L type Ca²⁺ channel and decrease Ca²⁺ cytoplasmic concentration, diminishing myocardial contractility, automatism and stimulus conduction, and facilitating peripheral vascular relaxation. Dihydropyridine type of Ca²⁺ channel blockers at therapeutic dose have no action on myocardial contractility, cardiac rhythm or stimulus conduction, acting almost exclusively on arterial smooth muscle cells. Consequently, they are effective to control arterial blood pressure in hypertensive and to manage coronary artery disease patients. It has bee shown that theses drugs have antiatherosclerotic activity, they decrease the atheromatous plaques growing and improve the regression of atherosclerotic lesions, effects that have been euphemistically named as "pleitropic". In vitro and in vivo investigations have demonstrated that calcium antagonists may influence endogenous antioxidant activity, inhibit fibroblasts and vascular smooth muscle proliferation, reduce the cellular and platelet adhesion, have antithrombogenic actions, and improve the nitric oxide endothelial production. Taken as a whole calcium antagonists may slow down the process of atherosclerosis. This findings partially explain the improvement frequently seen during the follow-up of hypertensive patients or those with coronary artery disease, in clinical trials with calcium antagonists, that exceed the benefits expected by simply lowering arterial pressure.