Do persons taking seizure medicines need to be concerned about interactions?

Yes. Most seizure medicines (also known as antiepileptic drugs or AEDs) interact with each other and with other medicines. Such interactions are common and can be dangerous. The effects of interactions between two medications vary. Some seizure medicines can lower or raise the levels of other types of medicines in your blood. Some combinations cause the levels of both medications to fall, some cause one level to fall and one level to rise, and some cause unpredictable effects.

If you've been taking the same combination of medicines for a long time and are doing well, you probably don't need to be too concerned. But if you are just starting one of the medicines or are having problems, check with your doctor.

How can I prevent interactions between my medicines?

Make sure you are under the care of a doctor who knows about all the medications you are taking. Also, tell your pharmacist or doctor about all over-the-counter medications you use, including herbs and dietary supplements, because some of them can affect seizure medicine levels, cause seizures in someone who has never had a seizure, or increase seizure frequency in a person with epilepsy.

Can I take birth control pills and seizure medicines?

Most women with epilepsy can take birth control pills without affecting seizure control. Although there is usually no change when the pills are started, some women have slightly improved seizure control and some have a slight worsening.

Do seizure medicines decrease the effectiveness of birth control pills?

Some seizure medicines reduce the effectiveness of birth control pills by increasing the breakdown, or metabolism, of estrogen and progesterone by the liver and thereby increasing the chances of getting pregnant while on the pill. If you are a sexually active woman taking birth control pills, ask your doctor if the type of seizure medicines you're taking will reduce the effectiveness of birth control pills. The best-known seizure medicines that interact in this way with birth control pills are Tegretol, Carbatrol, Dilantin, Phenytek, phenobarbital, Mysoline, Trileptal, and Topamax.

Topic Editor:Steven C. Schachter, M.D.
Last Reviewed:12/15/06