[Pharmacologic bases of cardiovascular therapy with diuretics]

Diuretics may have high, medium or low diuretic potency and their main site of diuretic action at the ascending limb of Henle's loop or at different biochemical sites of the distal tubulus. Loop diuretics have high diuretic potency, act abruptly, are not antihypertensives when prescribed as a monotherapy and are potentially ototoxic. The diuretics acting at the distal tubulus have a gentle time-course of diuretic activity and variable potencies and other properties. The mose frequent side-effect of diuretics is hypokalemia, whose development may be partially prevented by the prescription of a sodium restricted diet. Arrhythmias provoked by diuretics-induced hypokalaemia should be treated with magnesium and potassium. The most frequent drug interaction of diuretics is with unspecific inhibitors of prostaglandin's synthesis (aspirin and indomethacin) which decrease diuretic effects. Diuretics are indicated in the treatment of acute heart failure because of their direct and indirect vasoactive properties, in the treatment of chronic cardiac insufficiency because of their diuretic and vasodilatatory properties and, those diuretics which show as antihypertensives, are first choice drugs in hypertension.