PHARMACOKINETICS OF CARBAMAZEPINE IN THE NEONATE AND IN THE CHILD

Abstract

Pharmacokinetic studies of carbamazepine were made in 7 newborns and in 5 children. They were hospitalized for epilepsy and were receiving drugs i.e., phenobarbital alone or in association with other antiepileptic drugs, but not with carbamazepine. The drug was given by oral route with a mean dose of 17.2 mg/kg. The determination of carbamazepine concentration in serum was made by GLC on a 50 .mu.l sample. A 1-compartment body model was used to determine the pharmacokinetic constants with 1st order rate constants for absorption and elimination. Absorption was generally delayed by .apprx. 1/2 h, the maximum concentrations ranging from 3.14-10 .mu.g/ml at 2 and 9 h after administration. The mean half-life [t1/2] for absorption was 1.42 .+-. 0.34 h. The mean t1/2 for elimination was 8.76 .+-. 0.85 h. The t1/2 for elimination was much shorter than those already described even in multiple dosing epileptic adult patients. The pharmacokinetic parameters were used to predict blood levels in chronic treatment in 3 children. The predicted steady state concentrations disagreed with the concentrations measured.