Comparison of piretanide and chlorothiazide in the treatment of cardiac failure.

Piretanide, a diuretic that acts on the loop of Henle, was used to treat patients with cardiac failure. Over a three-day period it caused a significant dose related diuresis and weight loss. It was as effective as chlorothiazide in the control of cardiac failure and was well tolerated by the patients. Potassium loss was less than occurred with chlorothiazide. Its role in the treatment of cardiac failure requires further study and warrants further investigation. The study also showed that many patients with cardiac failure receive diuretic drugs which are not necessary.