Hormonal contraception and epilepsy

Attempts to normalize lifestyle and optimize quality of life in women with epilepsy should include the option of a reliable method of birth control, including oral contraceptives (OCs). Despite the well-known effects of estrogen on lowering seizure threshold, it has never been shown that estrogen-containing OCs worsen seizures in epileptic patients. In theory, the presence of progesterone (which is known to inhibit seizures experimentally) in OCs could counterbalance the seizure-promoting effects of estrogen. However, there is evidence that some OCs may fail when combined with antiepileptic drugs (AEDs), possibly because of the latters' inducing effects on endogenous estradiol and progesterone. Physicians have a duty to offer appropriate and accurate counseling to epileptic patients concerning optimal choice in the use of OCs for those considering this method of contraception. Recommendations include possible use of a noninducing AED, or (for patients taking inducing AEDs) use of an OC containing > or = 50 microg estrogen. Patients should be warned that midcycle bleeding indicates possible OC failure and that the absence of such bleeding is not an indication of OC effectiveness. Additional contraceptive measures are also advised.