Women and epilepsy
Which antiepileptic drug (AED)?
The goal of epilepsy treatment is to completely prevent seizures, and this is achievable in about 70% of cases. The most appropriate drug for the specific type (or syndrome) of epilepsy should be used.
Sometimes, an adverse or allergic reaction to the first medication prescribed occurs and then another antiepileptic drug (AED) is required.
As a general rule (and exceptions will occur), any AEDs can be used for focal epilepsies while sodium valproate, lamotrigine, topiramate, levetiracetam and perampanel are the AEDs used most often for the generalised epilepsies. Unfortunately, valproate and to a lesser extent topiramate, have been shown to cause an increased risk of major malformations in developing babies. Valproate may also cause learning difficulties and increase the risk of autism in children exposed to valproate in pregnancy.
Therefore, valproate must be avoided in women of childbearing age.
Levetiracetam and lamotrigine are better initial choices in women with generalised epilepsy. Only after other antiepileptic drugs have failed to be effective should valproate be considered. If valproate is absolutely essential to control seizures, then the lowest effective dose should be used. Supplementary folic acid is advised to all women, especially those on AEDs and of childbearing age, to reduce risks of malformations. (Talk to your doctor about the dose but it’s usually about 1mg /day).
Contraception and antiepileptic drugs
For women who want user-independent highly effective contraception, the Mirena intrauterine device may be the appropriate choice. Oral Contraceptive Pills (OCPs) are effective for many women on AEDs as long as they are taken daily at the same time and are not forgotten. It is important to ask your doctor about any possible problems with the OCP and your AED because some AEDs may enhance the metabolic breakdown of the OCP and also may affect other implanted hormones such as Implanon or Depo-provera. This might increase the risk of an unexpected pregnancy. The AEDs with this disadvantage include phenytoin, carbamazepine, barbiturates and also topiramate and perampanel in higher doses. If these methods are used, your doctor may consider prescribing a higher oestrogen containing OCP. The use of an additional barrier contraceptive method will help to ensure contraception. Some oral hormones can lower blood lamotrigine levels and may increase the risk of seizures.
Do antiepileptic drugs affect weight?
While there are reports of many AEDs tending to cause weight gain, sodium valproate is probably the most recognised. Topiramate may suppress appetite and induce weight loss.
The menstrual cycle and seizure patterns
Increased seizures around the time of the menstrual period are called Catamenial epilepsy. In some women, there are two peaks in seizure occurrence – one peak at the time of ovulation and another just before or during the menses. This occurs because of direct hormone effects on epilepsy and also the effects of cyclic hormones on AED metabolism.
Antiepileptic drugs and bone health
Phenytoin, carbamazepine and valproate can increase bone turnover which may lead to osteoporosis and increase risk of a bone fracture. Less is known about the new AEDs in this regard but they seem to be less problematic. It is important to ensure that there is an adequate intake of dietary calcium and that Vitamin D levels (normally obtained from exposure to sunlight) are sufficient. If the Vitamin D level in the serum is low in women taking these AEDs, then consideration should be given to Vitamin D supplementation.
Acknowledgement: Special thanks to Dr Cecilie Lander and Dr Lata Vadlamudi for writing this fact sheet.
You can download this information in the factsheets below about women and epilepsy.