Naftidrofuryl (CAS 31329-57-4) is used, mainly in elderly patients, in the treatment of various vascular disorders. The aim of this study was to evaluate and compare the pharmacokinetics of naftidrofuryl after single oral administration of a 200 mg naftidrofuryl tablet (Praxilene) in caucasian male and female subjects with renal impairment versus healthy volunteers. This prospective and open study was conducted in three parallel groups: Group A = healthy subjects with a Cl(CR) > 80 ml/min, Group B = uraemic patients with a 20 < or = Cl(CR) < 40 ml/min, Group C = uraemic patients with a Cl(CR) < 20 ml/min. Blood samples were taken over a period of 32 h after dosing. The mean values (+/-SD) of the pharmacokinetic parameters of naftidrofuryl for group A were as follows: tmax: 1.3 h (median), Cmax: 174 +/- 46 ng/ml, t(1/2 beta): 4.4 +/- 1.1 h, AUC(0-infinity): 1541 +/- 384 ng x h/ml; for group B: tmax: 2.5 h (median), Cmax: 239 +/- 94 ng/ml, t(1/2 beta): 5.0 +/- 1.2 h, AUC(0-infinity): 2361 +/- 751 ng x h/ml; for group C: tmax: 3.0 h (median), Cmax: 236 +/- 104 ng/ml, t(1/2 beta): 5.0 +/- 2.1 h, AUC(0-infinity): 2488 +/- 2003 ng x h/ml. The statistical analysis was performed on the pharmacokinetic parameters with one-way ANOVA in order to compare each group. No significant difference between each group was observed. In conclusion, renal insufficiency did not appear to influence the pharmacokinetic profile of oral naftidrofuryl.