[Pharmacokinetics of cefixime in patients with impaired renal function]

Cefixime (CFIX) was given orally in a single dose of 100 mg to 7 patients with varying degrees of impaired renal function (Ccr 12.0-56.7 ml/min) and serum concentrations and urinary excretion rates were measured with time for the first 24 hours by the bioassay method to investigate in vivo pharmacokinetics of the drug. The results obtained are summarized as follows. The mean peak serum concentration of CFIX in 3 patients with moderately impaired renal function (group I: Ccr greater than or equal to 30-less than 60 ml/min) was 2.04 micrograms/ml at 6 hours after dosing and gradually declined to 0.10 microgram/ml at 24 hours after dosing. The half-life was 4.15 hours. The mean peak serum concentration of CFIX achieved was 2.27 micrograms/ml at 8 hours after dosing in 4 patients with severely impaired renal function (group II: Ccr greater than or equal to 10-less than 30 ml/min) and the concentration of CFIX was 0.99 microgram/ml even after 24 hours. The half-life was prolonged to 11.05 hours. There was no great difference between groups I and II in the first 24-hour urinary excretion rates. However, the first 4-hour urinary excretion accounted for 2.14% of the administered dose of CFIX in group I but only 0.47% in group II. Urinary concentrations of CFIX peaked at 4-6 hours after dosing in both groups, and thereafter gradually decreased in group I. Whereas, they did not decline much in group II until 24 hours after dosing.(ABSTRACT TRUNCATED AT 250 WORDS)