[Pharmacokinetic properties of cefixime]

After a 200 mg intravenous or oral dose, the absolute bioavailability of cefixime, evaluated by comparison of areas under the serum concentration-time curve values, is 50 per cent. Because food has no effect on peak serum concentrations or on the extent of drug absorption, cefixime can be taken with or without meals. Protein binding is 70 per cent. Cefixime is cleared, mainly unchanged, partly by the liver (60 per cent) and partly by the kidneys (40 per cent). The elimination half-life varies between 3 and 4 hours. Plasma concentrations increase linearly but not proportionally to doses. No significant accumulation was observed after repeated administration in young and elderly subjects. The pharmacokinetic profile of cefixime is significantly altered in patients with marked renal impairment (creatinine clearance less than 20 ml/min), and in such cases dosage should be reduced from 400 to 200 mg/day. Haemodialysis or peritoneal dialysis do not remove significant amounts of the drug from the body. In cirrhotic patients, no dosage adjustment is needed, although the elimination half-life is increased twofold (congruent to 6.5 hours). The extravascular and tissue diffusion of cefixime is satisfactory in those areas where the organisms need to be eradicated.