Carbamazepine and carbamazepine-10,11- epoxide during pregnancy and postnatal period in epileptic mother and their nursed infants: pharmacokinetics and clinical effects.

A total of 11 epileptic mothers treated with carbamazepine (CBZ) as well as their 12 newborns were included in this study. Maternal CBZ concentrations remained rather constant during pregnancy and slightly increased after parturition. Carbamazepine-10, 11-epoxide ( CBZE ) levels were less predictable and either increased or decreased during pregnancy. Fetal/maternal serum concentration ratios at birth were 0.78 +/- 0.14 (n = 5) for CBZ and 0.75 +/- 0.09 (n = 5) for CBZE . Neonatal half-lives were 28 +/- 11 hours (n = 4) for CBZ and 20 and 24 hours (n = 2) for CBZE . maternal milk/serum concentration ratios of CBZ and CBZE were 0.39 +/- 0.22 (N = 11) and 0.49 +/- 0.28 (n = 6), respectively. The steady-state CBZ serum levels of nursed infants were about 1.0 micrograms/ml in all cases but one, where a maximum concentration of 4.7 micrograms/ml was reached. One of the infants had major malformations. Minor anomalies were less frequent in the CBZ group, compared to the whole group of infants exposed to anticonvulsive drugs other than CBZ and as frequent as in a matched pair control group of unexposed neonates. Neonatal somatic data were found to be below the corresponding values of neonates exposed to antiepileptic drugs other than CBZ.