Aprotinin is a small protein (molecular weight 6512) and the normalized V values 0.23 l kg’1 and 0.28 l kg’1. Similar values were recorded for patients with normal and is absorbed and accumulated by the proximal tubule after glomerular filtration. Following tubular renal function [4, 5]. The elimination half-lives for the patients with renal impairment were 13.3 h and 14.9 h, absorption the molecule is degraded by lysosomal enzymes. The renal uptake of aprotinin is considered a the normalized clearance 0.013 l kg’1 h’1 and 0.015 l kg’1 h’1 and the AUC norm 67.6 l kg’1 h and typical example of the renal handling of small proteins [1, 2]. There are no pronounced changes in renal 78.2 l kg’1 h. In patients with normal renal function [4, 5] the range of mean elimination half-lives was 5.25 h function following aprotinin administration. It appears that aprotinin has no effect on blood pressure, glomeru- to 8.28 h, the range of mean normalized clearances 0.035 l kg’1 h’1 to 0.042 l kg’1 h’1, and the range of lar filtration rate, total renal plasma flow, or renal excretory function [3]. Single dose pharmacokinetics of mean AUC norm 24.0 l kg’1 h to 28.7 l kg’1 h. Therefore, with the dosage regimen studied, renal impairment high doses of aprotinin have been previously investigated in both young and elderly female patients with normal causes a substantial decrease in clearance of aprotinin, with a consequent increase in the elimination half-life renal function [4, 5]. We now describe the pharmacokinetics of a single intravenous dose of aprotinin and the AUC of aprotinin; renal impairment did not affect the maximum concentrations or the distribution (TrasylolB, Bayer AG, Wuppertal, Germany) in two patients with impaired renal function. This is the first half-life of the drug. report of the pharmacokinetics of aprotinin in patients with renal impairment [6]. The authors thank the nursing and technical staff of the The study was conducted according to the same FARMOVS Research Centre for assistance with the clinical protocol as reported previously by Schall et al. [4, 5], study, Dr M. J. Oelofsen for the aprotinin assays, Miss J. M. Erasmus for assistance with the statistical analysis, and except that patients with chronic renal impairment Mrs L. van der Westhuizen for assistance in preparing this (long-standing serum creatinine concentration of at least