A Double‐Blind, Placebo‐Controlled Study on the Effect of Vigabatrin on In Vivo Parameters of Hepatic Microsomal Enzyme Induction and on the Kinetics of Steroid Oral Contraceptives in Healthy Female Volunteers

Abstract

At therapeutic dosages, VGB did not modify in vivo indices of hepatic microsomal enzyme activity and did not interfere significantly with the CYP3A-mediated metabolism of ethinyl estradiol and levonorgestrel. Based on these data, VGB is unlikely to affect consistently the efficacy of steroid oral contraceptives or interact pharmacokinetically with drugs that are eliminated mainly by oxidative pathways, particularly those involving cytochrome CYP3A.