Pharmacokinetic comparison of cefroxadin (CGP 9000) and cephalexin by simultaneous administration to humans.

The pharmacokinetic parameters of cefroxadin and cephalexin were compared after simultaneous oral administration of the two cephalosporins to 21 subjects. The influence of the dose, the formulation, and food intake on these parameters was investigated. Both drugs were equally well absorbed from all of the tested formulations; identical percentages of the dose were recovered in the urine in all cases. The elimination half-life of cefroxadin and, consequently, the area under the plasma concentration-time curve were about 10% less than those of cephalexin. Plasma concentrations and cumulative excretion curves of the two drugs were almost superimposable. Food intake had the same effect on both drugs; absorption was slowed, but the amounts absorbed were almost the same as those in fasted subjects.