FUROSEMIDE DISPOSITION IN PATIENTS ON CAPD

Single doses of oral and intravenous furosemide were given to 8 health y male volunteers (40 mg) and 11 patients with renal failure maintaine d on continuous ambulatory peritoneal dialysis (CAPD) (80 mg). In the volunteers, absorption was variable. Only one half of the intravenous dose and one third of the oral dose was available for renal pharmacolo gical action as judged by the urinary recovery. In the patients, absor ption was also variable and was markedly delayed (t(max) 128 vs 90 min ) but more complete (bioavailability 70.1 vs 53.6%). The differences b etween the two groups were not significant, however (95% C.I.: -90 to 30 and -40.4 to 7.5 respectively). The mean elimination half-life was significantly longer in the patients following both the oral (228 vs 6 5.1 min) and intravenous dose (195 vs 60.3 min). The total body cleara nce of furosemide in the volunteers was 138 . ml . min(-1) and this wa s much lower in the CAPD patients (61.9 ml . min(-1)), in whom the ren al clearance was minimal. The peritoneal clearance of furosemide was n egligible. Although there were trends indicating differences in absorp tion between the two groups, the significant differences in furosemide disposition observed in CAPD patients were due to renal failure.