[Pharmacokinetic study of intravenous furosemide in nephrotic syndrome in children].

The pharmacokinetics and pharmacological effect of intravenous furosemide (F) (2 mg/kg body weight) were studied in 12 children with the nephrotic syndrome with or without renal failure (R.F.). The concentration of F in blood and urine was determined by a new spectrophotometric method. In the nephrotic syndrome alone, the rate of renal excretion was increased (increased slope of the pharmacokinetic curve, decreased t 1/2), which may be due to a decrease in the fraction bound to plasma albumin. In children with the nephrotic syndrome and renal failure, the decrease in the renal excretion of F was related to the degree of renal failure. In normal children the mean F clearance is 296. In patients with N.S. alone the clearance is greatly increased (X = 377) and in N.S. with R.F. it is reduced (0.17-90). The possible mechanisms and therapeutic implications of the results are discussed.