Anti-Seizure Drugs for Epilepsy

Reviewed by: HU Medical Review Board | Last reviewed: May 2022 | Last updated: June 2022

Epilepsy is a type of seizure disorder in which neurons (nerve cells in the brain) behave 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 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 Parkinson’s disease.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

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.

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.5Never stop taking or change the dose of your anti-seizure drugs without talking to your doctor first.

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