[Pharmacokinetics of azlocillin in chronic renal failure and hemodialysis patients].

The pharmacokinetics of azlocillin were studied in 16 patients with varying degrees of renal impairment (creatinine clearance Ccr ranging from 0 to 52 ml/min/1.73 m2) and on and off sessions in 4 of these patients on periodical haemodialysis. A single dose of azlocillin 80 mg/kg was given by intravenous infusion over 30 min. Maximum concentrations in the sera of patients with renal impairment were the same as in normal subjects, ranging from 300 to 400 micrograms/ml. The elimination half-life (t 1/2) increased as renal function deteriorated, with values of 1.11 h in subjects with healthy kidneys to 5.66 h in patients with Ccr less than 15 ml/min (maximum 8.38 h). The apparent volume of distribution (Vd) was unchanged in patients with renal impairment but was significantly increased in patients on haemodialysis. The mean percentage of the dose administered excreted in the urines decreased from 60-70% in normal subjects to about 11% in patients with severe renal failure, but urinary concentrations remained above therapeutic levels. The extra-renal elimination of azlocillin was unmodified by renal impairment. Azlocillin is easily removed by dialysis: t 1/2 values between and during 6 h sessions of haemodialysis were 6.55 h and 2.81 h respectively, corresponding to a 45.8% extraction on the dialyser. These results are comparable to those found in the literature and can be used as a basis for adjusting azlocillin dosage to the degree of renal function.