Carbamazepine coadministration with an oral contraceptive: effects on steroid pharmacokinetics, ovulation, and bleeding.

ABSTRACT:

Purpose

Antiepileptic drugs (AEDs) are widely used in reproductive-age women. The AED carbamazepine (CBZ) induces the hepatic cytochrome P450 system, thereby accelerating hormone metabolism. We sought to assess the pharmacodynamic effects of CBZ on breakthrough bleeding and ovulation during oral contraceptive (OC) use.

Methods

A double-blind, randomized, crossover study of healthy women ages 18-35 years. Participants took an OC containing 20 μg ethinyl estradiol (EE) and 100 μg levonorgestrel (LNG) for 4 months. Concurrently, participants took 600 mg CBZ or a matching placebo for 2 months each, administered in random order. During the second month of CBZ or placebo, we measured EE and LNG levels 12 times over 24 h, ovarian follicular diameters with eight biweekly vaginal ult

SUBMITTER: Davis AR 

PROVIDER: S-EPMC3057928 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature