Comparative bioavailability of two furosemide formulations in humans.
Twelve healthy male volunteers participated in a balanced crossover comparison of a brand-name and generic furosemide formulations. Each treatment was given as a single 40-mg tablet following an overnight fast. Furosemide concentrations in plasma and urine were determined up to 24 h after treatment; urine output and urinary sodium excretion were also measured. In comparison with the brand-name tablets, generic furosemide was significantly less bioavailable. Using a 95% confidence interval approach, generic furosemide gave up to 66% lower maximum furosemide plasma levels, up to 52% less area under the plasma level curve to infinite time, and up to 37% less urinary recovery of furosemide. Comparison of the effect of the two treatments was a less sensitive measurement of bioequivalence. Confidence intervals for differences in urinary output and sodium excretion over the period of maximum effect (0-4 h) were, however, asymmetrical, and pharmacodynamic differences between treatments were significant at the 10% level.
D000293:Adolescent; D000328:Adult; D001682:Biological Availability; D004231:Diuresis / Q000187:drug effects; D005665:Furosemide / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D013607:Tablets; D013810:Therapeutic Equivalency
D013607:Tablets; D005665:Furosemide