Fycompa (perampanel) is a brand-name medication that’s prescribed to treat certain types of seizures in adults and some children. As with other drugs, Fycompa can cause side effects, such as dizziness, fatigue, and headache.

Fycompa has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Side effect specifics” section below.

Fycompa 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. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Fycompa in clinical trials:

Mild side effects can occur with Fycompa use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Fycompa’s prescribing information.

Mild side effects that have been reported with Fycompa include:

  • dizziness
  • fatigue
  • abdominal pain
  • nausea or vomiting
  • difficulty walking
  • anxiety
  • sleepiness
  • vertigo (spinning sensation)
  • weight gain (see “Side effect specifics” below)

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the FDA approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Fycompa and want to tell the FDA about it, visit MedWatch.

Fycompa may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Fycompa’s prescribing information.

If you develop serious side effects while taking Fycompa, 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 and their symptoms include:

ALLERGIC REACTION

For some people, Fycompa can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome (a severe allergic reaction) was reported in clinical trials of Fycompa. DRESS may include symptoms such as:

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Fycompa, your doctor may recommend taking a different medication instead.

Fycompa may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How do side effects of Fycompa compare with those seen with Keppra?

Fycompa and Keppra are both used to treat certain types of seizures. They have many similar side effects, but some different ones as well.

The most common side effects caused by both Fycompa and Keppra are sleepiness, dizziness, and headaches. While Fycompa can cause weight gain, weight loss has been reported with Keppra. Mild changes in blood counts were also reported with Keppra, but not with Fycompa.

Fycompa and Keppra can also cause severe side effects. These include serious skin reactions, behavioral or mental health changes, and suicidal thoughts or behaviors. Fycompa has a boxed warning for serious behavior and mental health changes. This is the most serious warning from the FDA. For more information, see the “Side effect specifics” section below.

If you have questions or concerns about side effects with Fycompa or Keppra, talk with your doctor or pharmacist.

Can Fycompa cause withdrawal side effects?

Yes, all antiseizure medications, including Fycompa, can cause withdrawal side effects if a person with a seizure disorder stops taking the drug. This can result in more frequent or life threatening seizures.

Withdrawal symptoms more commonly include:

Don’t stop taking Fycompa without talking with your doctor first. If you and your doctor decide to stop treatment with Fycompa, they’ll likely have you decrease your Fycompa dosage slowly over time.

Learn more about some of the side effects that Fycompa may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Fycompa.

Weight gain

Fycompa can cause weight gain in some people. The average weight gain reported in clinical trials of the drug was 1.1 kilograms, which is about 2.5 pounds. This was common in people who took Fycompa for both partial-onset seizures and primary generalized tonic-clonic seizures.

What you can do

Talk with your doctor if you have concerns about weight gain while taking Fycompa. They can recommend ways to help manage your weight, including eating a balanced diet and doing regular exercise.

Serious behavior and mental health changes

Fycompa has a boxed warning about the risk of serious behavior and mental health changes. A boxed warning is the most serious warning from the FDA. Changes in personality, mood, or behavior were common in clinical trials of Fycompa. Aggression-related side effects were the most frequently reported behavioral changes.

Other mental health or behavioral changes included:

These side effects occurred in both people diagnosed with mental health conditions and those with no previous history of them. In some cases, Fycompa worsened symptoms in people with previously diagnosed mental health conditions, such as depression or anxiety.

The risk of side effects may increase during the first few weeks after starting therapy or after dosage increases. The risk may also increase when taking higher doses of Fycompa. In rare cases, some behavior changes in people taking Fycompa were serious and life threatening, including thoughts of violence or homicide.

What you can do

Call your doctor immediately if you or anyone around you notice a change in your mental health or behavior while taking Fycompa. If you think you’re having a medical emergency, immediately call 911 or your local emergency number.

If you experience changes in mental health or behaviors while taking Fycompa, your doctor will likely decrease the dosage or have you stop taking the drug. In some cases, they may suggest you talk with a mental health professional.

Below is important information you should consider before taking Fycompa.

Fycompa has a boxed warning. A boxed warning is the most serious warning from the FDA. For details, see the “Side effect specifics” section above.

Other precautions

Before taking Fycompa, discuss your health history with your doctor. Fycompa 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:

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

  • Ask the tough question: “Are you considering suicide?”
  • Listen to the person without judgment.
  • Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
  • Stay with the person until professional help arrives.
  • Try to remove any weapons, medications, or other potentially harmful objects if it’s safe to do so.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The 988 Suicide and Crisis Lifeline is available 24 hours a day at 988. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 988.

Find more links and local resources.

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Disclaimer: Medical News Today 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.