Pharmacodynamic and pharmacokinetic study of a slow-release formulation of furosemide in man

A slow-release formulation of 40 mg furosemide as capsules (Eutensin) was investigated for its pharmacokinetic and pharmacodynamic properties in comparison with conventional tablets containing 40 mg furosemide (Lasix) in a single-blind clinical pharmacological trial in 6 healthy subjects. The following results were obtained: 1. The AUC0-24 after the administration of slow-release (SR) furosemide was about 42% of that after furosemide tablets. 2. Urine volume and urinary excretion of Na and Cl were significantly greater after furosemide tablets than after SR furosemide during the first 10 h after administration. No significant difference was observed between the two formulations in the urinary excretion of K, creatinine and uric acid. No significant difference was noted in every tested pharmacodynamic parameter during the cumulative 24 h after administration. It was concluded that SR furosemide may be used in the treatment of hypertension due to its characteristics of a slow-release diuretic feature, delayed peak blood concentration, delayed maximum diuretic effect and prolonged duration of action.