Serum sex hormone levels after replacing carbamazepine with oxcarbazepine.

The function of the hepatic P450 enzyme system was evaluated by measuring the kinetics of antipyrine and serum sex hormone levels were determined in 12 male patients with epilepsy during carbamazepine medication, and two and six months after changing their medication to oxcarbazepine. Antipyrine t1/2 increased and antipyrine CL decreased after the change reflecting normalisation of the liver P450 enzyme system function. Serum sex hormone binding globulin levels decreased, and serum dehydroepiandrosterone sulphate increased after the change. The results show that the carbamazepine-associated induction of the liver P450 enzyme system and changes in serum sex hormone balance can be avoided by replacing carbamazepine with oxcarbazepine.