Elimination of furosemide in healthy subjects and in those with renal failure

Furosemide was administered intravenously to 5 healthy volunteers and 15 patients with various degrees of renal failure. Two patients were given the drug orally, The plasma half‐life offurosemide averaged 0.79 hr in the healthy subjects, Although most patients with kidney disease had a prolonged half‐life (t ½ ), up 10 24.58 hr, some with advanced renalfailure had an almost normal t ½ . The plasma clearance of furosemide, which in the normal subjects averaged 194 ml/min, decreased proportionally with decreasing creatinine clearance, as did the renal clearance, which in the healthy subjects averaged 95 ml/min. There was no correlation between kidney function and the apparent volume of distribution or of non renal clearance. One patient was given 35 S‐labeled furosemide intravenously. Although the furosemide plasma t ½ was essentially normal, the elimination rate of metabolites was decreased. Unlike that of healthy subjects, the main route of excretion of label was in the feces.