Single Dose Study to Compare the Pharmacodynamics of Torasemide-PR 10 mg,Torasemide-IR 10 mg and Furosemide-IR 40 mg in Patients With Compensated Heart Failure

This is a randomized, open-label, blinded-endpoint, crossover, single dose study to compare the pharmacodynamics of Torasemide-PR 10 mg, Torasemide-IR10 mg and furosemide-IR 40 mg. 30 patients of both sexes with CHF with a maximum imbalance of 60:40% in either direction will be included in the study. Patients with compensated heart failure, grade II or III as defined by the European Society of Cardiology, with a duration of ≥ 3 months at the time of inclusion documented in the patient's record or patients who previously required diuretic therapy. Principal variable will be the efficiency of sodium excretion that will be assessed as the ratio between the average drug-induced natriuresis and the average drug recovered in urine over 24 hours. The difference between the efficiency of 24 hour sodium excretion following administration of torasemide PR and furosemide will be formally tested by means of a Students t-test for paired samples. The test will be two-sided at 5% significance level. Efficiency changes over time will also be assessed, however will not be subject to formal statistical testing.