[Modern differential therapy with diuretics].

Diuretics block different electrolyte transporters in renal tubular cells. Their predominant action is inhibition of renal sodium chloride reabsorption, however, and achievement of a negative body sodium balance is the principal goal of diuretic therapy in patients with hypertension and edema. Several classes of diuretics can be distinguished with respect to the sites of sodium reabsorption along the nephron, but loop diuretics and distal-tubular diuretics (incl. thiazides) are the most widely used. The latter have a less potent natriuretic effect than loop diuretics, but their long duration of action predispose them for treatment of patients with uncomplicated hypertension. In conditions of gross edema, e.g. heart and/or renal failure, distal-tubular diuretics lose their efficacy and must be replaced by or combined with loop diuretics ("sequential nephron blockade"). Aldosterone antagonists are unique among diuretics because they improve survival in patients with heart failure independently of their effect on sodium metabolism.