Anti-Seizure Drugs for Epilepsy

Reviewed by: HU Medical Review Board | Last reviewed: November 2023 | Last updated: November 2023

Epilepsy is a type of seizure disorder in which neurons (nerve cells in the brain) communicate abnormally. Neurons normally create tiny electrical signals in a regular rhythm. These signals tell other parts of the brain and body what to do.1,2

With epilepsy, neurons create too many electrical signals, too quickly. Some doctors describe this as an electrical storm in the brain. This storm causes a wide variety of physical and mental changes known as seizures.1,2

Someone is thought to have epilepsy if they have 2 or more unprovoked seizures more than 24 hours apart. Unprovoked means the seizures are not caused by some other condition. Conditions that can cause seizures include alcohol withdrawal, drug overdoses, hormone imbalances, or very low blood sugar.1,2

Unlike some other health conditions, prescription medicine is usually the first line of treatment when someone is diagnosed with epilepsy. There are dozens of different drugs prescribed for epilepsy seizures. To pick an anti-seizure drug, your doctor will need to consider several things about you, such as:3-5

  • Type of seizure and type of epilepsy
  • Age
  • Other health conditions
  • Other medicines you take
  • Pregnancy,  breastfeeding status, or plans to become pregnant
  • Potential drug side effects
  • Cost
  • Lifestyle issues such as type of work or caring for small children

Some epilepsy drugs can be started quickly, while others need to be slowly increased over time. The good news is that epilepsy medicines control seizures in 7 out of 10 people.6,7

Types of anti-seizure drugs

In general, epilepsy drugs fall into 2 types: broad-spectrum and narrow-spectrum. Broad-spectrum anti-seizure drugs treat a wide variety of seizure types. These drugs are prescribed for generalized seizures and when the seizure type is unknown. Narrow-spectrum drugs best treat focal seizures. Some people are prescribed both broad- and narrow-spectrum drugs.3,4,6

Anti-seizure drugs may also be grouped by how they work. How a drug works in the body is called its mechanism of action. Epilepsy drugs fall into these basic categories:4

Many drugs used to treat seizures also treat other health conditions, including migraines, mood disorders, neuropathic pain, and movement disorders.3,4

Common side effects of anti-seizure drugs

Anti-seizure drugs often cause side effects. Most side effects are mild and wear off over time, but some do not. The most common side effects of epilepsy medicines include:3,4

  • Headache
  • Fatigue
  • Dizziness
  • Loss of balance
  • Blurry vision
  • Changes in sleep, especially insomnia
  • Stomach upset
  • Weight gain or weight loss
  • Brain fog
  • Change in mood, including irritability, anxiety, and depression
  • Osteoporosis (bone loss)
  • Heart issues
  • Low levels of salt in the blood
  • Reduced vitamin levels, such as B12 and folate

Less common side effects include:3,4

  • Serious skin rash (Stevens-Johnson syndrome)
  • Aplastic anemia (when the body stops producing new blood cells)
  • Psychosis
  • Suicidal thoughts

When you begin taking certain anti-seizure drugs, your doctor will order regular blood tests. These test results help establish the right dose for you and to check if the drug is affecting other parts of your body, such as your liver, bone marrow, and kidneys.5-7

It may take some time to find the right anti-seizure drug, the right dose, or the right time of day to control your seizures and minimize side effects.

These are not all the possible side effects of epilepsy drugs. Talk to your doctor about what to expect when taking any epilepsy drugs. You also should call your doctor if you have any changes that concern you when taking epilepsy drugs.

Monitoring for side effects of epilepsy medication

Anyone taking anti-seizure medicines needs regular follow-up care to monitor for side effects. It is common for someone to get blood tests once a year. A complete blood count, metabolic panel, and liver function test are common. More frequent follow-up may be needed if the person also has liver disease, HIV, cancer, diabetes, or heart disease, or if they are pregnant.5

Never stop taking or change the dose of your anti-seizure drugs without talking to your doctor first.

Before beginning treatment for epilepsy, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.

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Treatment results and side effects can vary from person to person. This treatment information is not meant to replace professional medical advice. Talk to your doctor about what to expect before starting and while taking any treatment.