DIURETICS, drugs used to increase the elimination of urine. Such diuretics may be di rect, in that they affect the renal epithelium, or indirect, in that they increase the blood pres sure within the kidney and thus increase the urine elimination. This is largely an artificial classification, since it would seem that urine is always a true secretion and not a filtrate, and the renal epithelium must always be involved in the process of manufacture. Still it is a sub division that has received wide recognition. Diuretics are frequently used in a number of heart, lung and kidney diseases; because in the normal elimination of urine certain catabolic products are cast off from the body in the urine. If they are retained, however, they give rise to various degrees of intoxication, which may be even fatal. Thus in certain heart diseases, either from insufficient pressure or from accompany ing disease of the blood vessels, the elimination of the ordinary amount of urinary solids may be insufficient and result in poisoning. Hence
diuretics, by increasing the elimination of urine, increases the output of these poisonous prod ucts. In all patients for whom diuretics are useful, certain concomitant drugs are of benefit, those namely that empty the bowels freely and those that increase the elimination of perspira tion. Of the numerous diuretics the saline salts of potassium, sodium, lithium, calcium, magnesium, the heart tonics, such as digitalis, adonis, caffeine, strophanthus convallaria, theo bromine, are most frequently employed. To this list calomel, copaiba, cubebs, juniper, oil of sandal and other irritating diuretics might be added. Injections of hot water into the rectum cause a pronounced diuresis, and this method is now recognized to be one of the best modes of inducing an increased elimination of urine.