The Use of Chlorothiazide in the Nephrotic Syndrome

The new diuretic agent, chlorothiazide (6-chloro-7-sulfamyl-1,2,4-benzot benzothiadiazine-1,1-dioxide),*is useful in the treatment of many clinical disorders, including congestive heart failure, cirrhosis, nephrosis, essential hypertension, premenstrual edema, and toxemia of pregnancy.¹⁻⁹Among its various clinical advantages are (1) remarkable effectiveness when administered orally; (2) prompt diuretic action, consisting of water diuresis, natruresis, and chloruresis but only minimal kaluresis; (3) persistent activity and lack of tolerance until edema subsides; (4) antihypertensive action, and (5) minimal side-effects or toxic reactions. Basic pharmacologic studies have demonstrated that chlorothiazide inhibits carbonic anhydrase in vitro but not significantly in vivo,²and clinical trials in man indicate that its diuretic action is qualitatively similar to that of the mercurial diuretics. In short-term animal experiments,¹maximal diuresis was observed at 40 minutes after intravenous administration, with a total duration of effect of about 4 hours. The peak response after oral administration occurred at 4 hours,