Levetiracetam can cause side effects that range from mild to serious. More common side effects include fatigue and increased risk of infection. If levetiracetam side effects become difficult to tolerate, talk with your doctor about coping tips or other treatment options.

Levetiracetam is a generic drug that’s used in adults and some children to treat certain types of seizures.

Keep reading to learn about the common, mild, and serious side effects levetiracetam can cause. To learn more about this medication, including its uses, dosage, and cost, see this levetiracetam overview article.

Note: The risk of side effects from levetiracetam may vary depending on the dosage you’re prescribed, but this risk is not affected by the tablet strength you take. The levetiracetam oral tablet comes in strengths of 250 milligrams (mg), 500 mg, 750 mg, and 1,000 mg. The levetiracetam ER oral tablet is available in strengths of 500 mg, 750 mg, and 1000 mg.

Levetiracetam can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. Talk with your doctor if side effects do not go away, get worse, or become too difficult to tolerate.

Examples of levetiracetam’s commonly reported side effects include:

  • aggression
  • irritability
  • decreased appetite
  • increased risk of infection (see “Tips for managing side effects” for details)
  • fatigue
  • nasal congestion
  • dizziness
  • sleepiness
  • weakness

Note: Sleepiness and weakness are especially common when you first start taking levetiracetam or after a dose increase. These side effects may go away as your body adjusts to the drug.

For details on common side effects, see the prescribing information for levetiracetam oral tablets or ER oral tablets.

Mild side effects have been reported with levetiracetam. These include:

  • aggression
  • irritability
  • decreased appetite
  • weakness
  • increased risk of infection (see “Tips for managing side effects” for details)
  • fatigue
  • sleepiness
  • nasal congestion
  • dizziness

In most cases, these side effects should be temporary, and some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. Do not stop levetiracetam treatment unless your doctor recommends it.

Levetiracetam may cause mild side effects other than those listed here. For details, see the prescribing information for levetiracetam oral tablets or ER oral tablets.

Levetiracetam may cause serious side effects. The following list may not include all possible serious side effects of the drug. For more information, you can refer to the prescribing information for levetiracetam oral tablets or ER oral tablets.

If you develop serious side effects while taking levetiracetam, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported include:

  • withdrawal seizures (more frequent or severe seizures) if levetiracetam is suddenly stopped
  • changes in behavior, such as aggressive behavior
  • difficulties with coordination could lead to problems in activities such as walking, speaking, or driving
  • severe skin reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS)
  • new or worsening depression, which may increase the risk of suicidal thoughts or behaviors (see “Tips for managing side effects” for details)

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect during treatment with Levetiracetam and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, levetiracetam can cause an allergic reaction. This side effect wasn’t reported in studies of levetiracetam oral tablets and ER oral tablets. But allergic reactions have been reported since the drug was approved for use.

In general, symptoms of an allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should continue levetiracetam treatment.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to levetiracetam, they may have you switch to a different treatment.

There may be things you can do to help make certain Levetiracetam side effects more manageable. If you have ongoing, worsening, or bothersome side effects, talk with your doctor or pharmacist. They can suggest tips for managing them or recommend other available treatment options for your condition.

Increased risk of infection

Infection was a common side effect reported in studies of levetiracetam oral tablets and ER oral tablets. Symptoms associated with this side effect can vary depending on the type of infection you have. But in general, steps you can take to manage symptoms of infection include:

New or worsening depression

Levetiracetam may cause new or worsening depression in some people. This was a common side effect reported in studies of levetiracetam oral tablets and ER oral tablets.

Steps you can take to manage this side effect include:

  • talking with your doctor if you experience new or worsening symptoms
  • watching for symptoms of depression in yourself, such as unusual changes in mood, loss of interest in activities that usually bring you joy, and suicidal thoughts or behaviors
  • calling 911 or your local emergency number if you think your symptoms are life threatening

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Before taking levetiracetam, discuss your health history with your doctor. Levetiracetam may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.