Diuretics in Nonedematous States: Physiological Basis for the Clinical Use

Diuretics may be utilized in the treatment of conditions not usually accompanied by sodium and water retention. The salutary effects on one group of conditions, such as pituitary and nephrogenic diabetes insipidus, renal tubular acidosis, and hypercalciuria, appear to depend primarily on the production of extracellular fluid volume contraction by the diuretic. Therapeutic success in another group, such as hypercalcemia and intoxication (either endogenous or exogenous), depends on the copious excretion of sodium and water induced by potent diuretics that ensures the excretion of the substances in question. Invariably this leads to a reduction in the plasma concentrations of such substances as calcium, halides, salicylates, some barbiturates, and uric acid. In addition, alkalinization of the urine and diuresis will reduce the noxious renal effects of substances like uric acid and cystine. Understanding the physiology of diuretic action is mandatory to institute appropriate therapy in these conditions.