Anticonvulsant and Antiepileptic Drugs

Antiepileptic drugs are medicines used to help treat epilepsy or seizures. They are also called anticonvulsants or antiseizure drugs. While these medicines are often used to treat seizures, they also may prevent migraine attacks.^1,2

How do anticonvulsant and antiepileptic drugs work?

It is unknown exactly how anti-seizure medicines help prevent migraine attacks. It is thought that these medicines calm hyper-excitable nerve cells, or neurons, in the brain. Antiepileptic medicines do not work as an acute treatment for a migraine. This means they will not stop a migraine attack that has started. They are meant to be taken daily to prevent migraine from developing.^2,3

Seizures are also caused by unregulated brain electrical activity. Antiepileptic drugs work by calming and controlling these electrical signals. For migraine, this calming effect may help control the brain pathways that lead to inflammation and discomfort.^1,2

Examples

There are many different types of antiepileptic medicines. But they are not all approved for treating migraine. The US Food and Drug Administration (FDA) has approved 2 antiepileptic drugs for preventing migraine.²

Antiepileptic drugs used for migraine include:^2,3

• Valproate – Valproate sodium (Depacon^®) and divalproex sodium (Depakote^®). These are both medicines in the same family. Divalproex sodium is made of an equal combination of valproic acid and sodium valproate.
• Topiramate (Topamax^®, Trokendi XR^®, Qudexy XR^®) – This medicine has fewer side effects compared to valproate.

Other antiepileptic medicines have been studied for use with migraine, but the results are mixed. For example, gabapentin may be used off-label for the prevention of migraine. It is thought to act on GABA and glutamate, two neurotransmitters linked to migraine.⁴

What are the possible side effects?

Side effects can vary depending on the specific treatment or medicine.

Side effects of valproate may include:¹

• Drowsiness
• Stomach pain
• Nausea, diarrhea, and vomiting
• Low platelet count
• Tremors
• Dizziness
• Double vision
• Weight gain
• Problems with walking or coordination
• Headache
• Weakness
• Increased appetite or loss of appetite
• Hair loss

Side effects of topiramate may include:¹

• Tingling in the hands and feet
• Nausea, vomiting, and diarrhea
• Stomach pain and cramps
• Fatigue
• Sleepiness
• Brain fog
• Hair loss
• Change in the way foods taste
• Loss of appetite and weight loss
• Dizziness

Side effects of gabapentin may include:¹

• Dizziness
• Drowsiness
• Lack of coordination
• Swelling of legs and feet
• Double vision
• Difficulty thinking
• Abnormal eye movements
• Tremors
• Jerky movements

While rare, antiepileptic medicines may also cause serious mental health side effects, including thoughts of hurting yourself or someone else. If you have suicidal thoughts or behavior, call the healthcare provider who prescribed this medicine immediately. You can also call the 988 Suicide Prevention Lifeline at any time by dialing 988.¹

It is best to avoid alcohol in combination with these treatments. This combination can increase sedation and the risk of side effects.^1,2

These are not all the possible side effects of anticonvulsant and antiepileptic drugs. Talk to your doctor about what to expect when taking this type of medicine. You also should call your healthcare provider if you have any changes that concern you when taking anticonvulsant and antiepileptic drugs.

Other things to know

In most cases, these medicines are started at a lower dose and then increased as tolerated. It may take some time to determine the dose of medicine that is the right fit for you in terms of efficacy and tolerability.^1,2

It may take up to 8 to 12 weeks at the target dose to see improvement in migraine. If you have at least some improvement, it may be worth continuing the medicine. Benefits can increase over 6 to 12 months of use.^1,2

Antiepileptic medicines can harm an unborn baby. You should also not breastfeed during treatment with antiepileptic medicines and for some time after the last dose. Talk to your doctor about your options for birth control and breastfeeding while taking antiepileptic medicines.¹

Antiepileptic medicines may interact with other medicines you take. Before beginning this treatment for migraine, tell your healthcare provider about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.