Interactions between hormonal contraception and antiepileptic drugs: Clinical and mechanistic considerations.

Antiepileptic drugs (AEDs) and hormonal contraceptives may affect each other's metabolism and clinical efficacy. Loss of seizure control and unplanned pregnancy may occur when these compounds are used concomitantly. Although a large number of available preparations yield a plethora of possible drug combinations, most of these drug interactions are predictable and, thus, avoidable. Unfortunately, there is a substantial lack of data regarding the newer AEDs. Detailed understanding of these issues is necessary for those who prescribe AEDs and/or hormonal contraception to women with epilepsy, as well as for those who provide comprehensive care, education and counseling to them, in order to reduce the unacceptably high number of unplanned pregnancies among women with epilepsy.