Comparison of intravenous piretanide and furosemide in patients with congestive heart failure

In order to compare the efficacy of piretanide, a loop diuretic, with furosemide in the setting of congestive heart failure, 20 patients with moderate-to-severe congestive heart failure were studied in a double-blind fashion. Ten patients received piretanide and 10 furosemide intravenously every 12 h for 3 days. Prior to treatment, the groups were indistinguishable in all relevant clinical characteristics. No major adverse reactions were encountered in either patient group. There was no ototoxicity, worsening of cardiac arrhythmias, worsening of diabetes, or systematic perturbation of the serum digoxin concentration. Patients in both groups had similar mild elevation in BUN and serum uric acid levels at the end of the study. There was an equal weight loss for patients in the two groups and an equal excretion of Na, K, and total volume of urine for the two groups. The urinary Na/K ratio was also indistinguishable between the two groups. In both groups, plasma aldosterone concentration tended to increase; there was no alteration in plasma renin activity. We conclude that piretanide and furosemide are equieffective for treatment of congestive heart failure in the doses used. Although in some settings piretanide is potassium sparing, we were not able to demonstrate this property in the population studied.