Ethacrynic Acid Effectiveness and Mode of Diuretic Action

ETHACRYNIC ACID is an unsaturated ketone derivative of phenoxyacetic acid* chemically different from other known diuretic agents.' Compounds of this general class have a significant ability to bind sulfhydryl groups in vitro. Ethacrynic acid was shown by Baer and associates2 to be highly effective as a diuretic in the dog, but not in the rat. A preliminary report from this laboratory indicated that the compound was a highly potent natriuretic and diuretic agent in man.3 This study also suggested that ethacrynic acid had a unique mode of action in the nephron. In the present communication results of a 2-year experience with ethacrynic acid are reported. During this period ethacrynic acid was found to produce effective natriuresis and diuresis in a study of 82 patients, many of whom had edema which was refractory to treatment with other diuretic agents. The results of a series of investigations designed to explore some of the mechanisms by which the compound alters electrolyte excretion and acid-base balance are also reported.