Kinetics of furosemide in children with chronic renal failure undergoing regular haemodialysis.

Furosemide was measured by gas-liquid chromatography in blood and dialysis fluid from 7 children with chronic renal failure, undergoing regular haemodialysis. It was administered chronically, in two or three daily doses (4.2-9.4mg/kg). Two children received 1 mg/kg intravenously for determination of the pharmacokinetics. The half-life was longer than in adults and in anephric patients on haemodialysis. Systemic and renal clearance were also much lower. Plasma protein binding in 2 out of 6 cases was reduced as compared to normal adults. The data do not suggest any need to modify the present dosage schedule despite the 4-5 fold increase in the half-life of furosemide. The contribution of haemodialysis to drug clearance was minimal, and accounted for less than 10% of the total clearance.