TARKA

Verapamil is a phenylalkylamine calcium antagonist which blocks the inward movement of calcium ions in cardiac muscle cells, in smooth muscle cells of the coronary and systemic arteries and in cells of the intracardiac conduction system. It lowers heart rate, increases myocardial perfusion and reduces coronary spasm. Because of its effect on the movement of calcium in the intracardiac conduction system, verapamil reduces automaticity, decreases conduction velocity and increases the refractory period.

Trandolapril is a prodrug, which is rapidly, non-specifically hydrolysed to its potent, long-acting active metabolite, trandolaprilat (other metabolites are inactive) and acts as an orally-active angiotensin converting enzyme inhibitor (ACE inhibitor) without a sulphydryl group. In addition to inhibition of plasma ACE, trandolapril has been experimentally shown to inhibit tissue ACE (particularly vascular, cardial and adrenal). The clinical relevance of tissue ACE inhibition has not been established in humans.