EFFECT OF FOOD ON THE ABSORPTION OF FRUSEMIDE AND BUMETANIDE IN MAN

1 The influence of food on the absorption of frusemide and bumetanide was compared in two separate randomized crossover studies. 2 On three separate occasions frusemide 40 mg was administered to eight healthy m ale volunteers intravenously, orally in the fasting state and orally a fter a standard breakfast. Blood and urine were collected at intervals over 8 h and urine alone for a further 16 h. The study was then repea ted in nine healthy volunteers using intravenous and oral bumetanide 2 mg. 3 Breakfast significantly reduced the peak plasma concentration o f frusemide from 2.35 +/- 0.49 to 0.51 +/- 0.19 mg l(-1) (95% confiden ce intervals (95% CI)=1.39 to 2.28 mg l(-1)) and delayed the time to p eak concentration from 0.69 +/- 0.21 to 1.91 +/- 0.93 h (95% CI=0.41 t o 2.03 h). The oral bioavailability of frusemide was significantly red uced by approximately 30% (75.6 +/- 10.6 to 43.2 +/- 16.8%; 95% CI=13. 5 to 51.4%). 4 With bumetanide, the meal also significantly reduced th e peak concentration from 0.097 +/- 0.015 to 0.036 +/- 0.012 mg l(-1) (95% CI=0.048 to 0.073 mg l(-1)) and delayed the time to peak from 0.5 3 +/- 0.08 to 1.36 +/- 0.72 h (95% CI=0.23 to 1.44h). However, food ha d no statistically significant effect on the bioavailability and urina ry recovery of bumetanide. 5 In this study, the absorption of bumetani de was affected less than frusemide by food.