Effects of CYP3A4/5 and ABCB1 genetic polymorphisms on carbamazepine metabolism and transport in Chinese patients with epilepsy treated with carbamazepine in monotherapy and bitherapy.

Objective: To examine the effects of cytochrome P450 3A4 (CYP3A4), cytochrome P450 3A5 (CYP3A5) and ATP-binding cassette sub-family B member 1 (ABCB1) genetic polymorphisms on carbamazepine (CBZ) plasma concentrations in Chinese patients with epilepsy using CBZ as monotherapy and bitherapy with phenytoin (PHT), phenobarbital (PB), or valproic acid (VPA).

Methods: Eighty-eight Chinese patients with epilepsy were recruited from Xiangya Hospital Central South University, of whom 66 patients were placed in the CBZ monotherapy group, 10 patients were placed in the CBZ bitherapy group combined with one enzyme-inducing anti-seizure medications (PHT or PB), and 12 patients were placed in the CBZ bitherapy group combined with VPA. Carbamazepine and carbamazepine-10,11-epoxide (CBZ-E) plasma concentration of these patients were measured.