Torasemide versus furosemide in patients with congestive heart failure: A double-masked, randomized study

A new loop diuretic torasemide has recently been introduced into international pharmacopoeia. Its chemical structure, 1-isopropyl-3-[4-(3-methyl-phenylamino)pyridine]-3-sulphonyl urea (pyridinylsulfonyl-urea), is not related to other loop diuretics, such as furosemide. It has been considered suitable for a broad spectrum of clinical settings, including heart failure, hepatic cirrhosis, hypertension, and chronic renal failure. In this study, we compared the efficacy and tolerability of torasemide and furosemide in patients with congestive heart failure (New York Heart Association) classes II and III. We observed that torasemide induced an intense diuresis (a statistically significant increase of 38% from day 3 and 75% on day 28 with respect to baseline) and increased excretion of urinary sodium and potassium, although no significant modification in plasma sodium and potassium levels was observed during the treatment period. Furosemide induced a comparable statistically significant increase of diuresis (24% on day 3 and 65% on day 28) and urinary potassium excretion associated with a significant decrease in serum potassium levels at the end of the treatment period. Two patients in group A and one patient in group B mere withdrawn from treatment because of adverse reactions (muscular cramps). It can be concluded that torasemide, as well as furosemide, appear to be potent diuretic compounds. The administration of torasemide produces an acceptable incidence of clinical side effects and can be indicated for use in chronic clinical conditions requiring an efficacious diuretic.