Anti-epileptic drugs and hormonal treatments

Epilepsy and the medications used in its treatment are known to affect the menstrual cycle, aspects of contraception, and bone health in women. Adolescence is an important time to review the diagnosis of both epilepsy and the epilepsy syndrome because of the implications and decisions, which should be made regarding antiepileptic drug (AED) treatment. In girls, once they are on AED therapy, seizure free, and driving, it becomes difficult to change therapy because of the risk of breakthrough seizures and the fact that the new AED may not be as effective as the first. So a treatment choice made in adolescence is often life-long. Therefore, women need to be started on an AED that currently appears to be the most suitable for their seizure type, has a low teratogenic risk, and hopefully does not interact with contraception. There are no contraindications to the use of non-hormonal methods of contraception in women with epilepsy. Nonenzyme-inducing AEDs (valproate, benzodiazepines, ethosuximide, levetiracetam, tiagabine, and zonisamide) do not show any interactions with the combined oral contraceptive. There are interactions between the combined oral contraceptive and hepatic microsomal-inducing AEDs (phenytoin, barbiturates, carbamazepine, topiramate [dosages >200 mg/day], oxcarbazepine, eslicarbazepine and perampanel [dosages >12 mg/day]) and lamotrigine. Women taking enzyme inducing AEDs should be encouraged to use a method of contraception that is unaffected by their epilepsy medication. Interactions between AEDs and other hormonal therapies are less well studied. Studies have suggested that women with epilepsy are at increased risk of fractures, osteoporosis, and osteomalacia. No studies have been undertaken looking at preventative therapies for these comorbidities. This article will concentrate on current contraceptive treatment options in patients taking AEDs.