Contraception for women with epilepsy.

The choice of a contraceptive drug can be challenging for women with epilepsy due to possible interactions between antiepileptic drugs (AEDs) and hormonal contraception. Enzyme-inducing AEDs can cause hormonal contraception to fail and can increase the risk of teratogenicity. Higher doses of oral contraceptives can overcome pharmacologic failure but may create additional risks. The effects of reproductive hormones on individual AEDs have recently been clarified, providing helpful guidelines for physicians and patients. Studies show that lamotrigine has a significantly increased clearance (> 50%) when used with combined oral contraceptives, which results in an increased seizure frequency in most patients. Useful alternatives to oral contraceptives include depot injections and intrauterine devices. Subdermal implants may increase the risk of pregnancy in women with epilepsy on enzyme-inducing AEDs. Depot medroxyprogesterone acetate is effective but can increase side effects. Intrauterine devices are an alternative to pharmacologic approaches because they lack drug-drug interactions and side effects.