SULFONAMYL DIURETICS--MECHANISM OF ACTION AND THERAPEUTIC USE.

The mechanism whereby sulfonamyl diuretics are effective is through the blockage of the renal tubular reabsorption of chloride. The excretion of sodium, potassium and water is a passive one to maintain ionic equilibrium. Chlorothiazide has been shown to be almost ineffective as a diuretic agent per se. Although it does block a moiety of the renal tubular reabsorption of bicarbonate, the effect is merely a transient one.