Advantages of the new loop diuretic torasemide over furosemide in patients with cirrhosis and ascites

Torasemide is a new loop diuretic with a longer half-life and
longer action than furosemide in healthy subjects. In order to
evaluate the pharmacodynamic effects, single oral doses of
furosemide (80 mg) and torasemide (20 mg), which were equipotent in
healthy subjects, were given to 14 patients with cirrhosis and
ascites. Before the study patients underwent an equilibration
period of 4 days without diuretics. The drugs were alternated
following a randomized double-blind cross-over design after a
wash-out period of at least 2 days. Urine was collected at defined
intervals for 24 h after drug administration and blood samples were
taken before, 6 h and 24 h after medication. Torasemide induced
greater cumulative 24 h diuresis (2863 ± 343 vs. 2111 ± 184 ml, p
< 0.01) than furosemide. Torasemide did not differ from
furosemide for cumulative 0–6 h sodium excretion (96 ± 17 vs. 92 ±
23 mmol sodium) but caused a more pronounced cumulative 6–24 h
natriuresis (38 ± 11 vs. 17 ± 4 mmol, p < 0.05). Five patients
exhibited a weak response to furosemide (0–36 mmol sodium/24 h,
median 24 mmol; 690–1460 ml urinary volume/24 h, median 1325 ml).
These patients showed significantly higher natriuresis and diuresis
following torasemide (26–136 mmol sodium/24 h, median 78 mmol, p
< 0.05; 1670–3610 ml urinary volume/24 h, median 2200 ml, p <
0.05). Twenty-four hours after administration of both drugs there
were no significant changes in hemodynamic, renal or hormonal
parameters. No adverse effects were noted with either treatment.
These findings suggest that torasemide might be more advantageous
than furosemide in the treatment of ascites due to cirrhosis.