Xcopri (cenobamate) is a prescription oral tablet used to treat focal (partial) onset seizures in adults. Xcopri can cause side effects that range from mild to serious. Examples include weight loss and drowsiness.

The active ingredient in Xcopri is cenobamate. (An active ingredient is what makes a drug work.)

Keep reading to learn about the common, mild, and serious side effects Xcopri can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Xcopri treatment. Examples of the drug’s commonly reported side effects include:

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Xcopri, visit MedWatch.

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

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. And do not stop taking Xcopri unless your doctor recommends it.

Xcopri may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.

Serious side effects have been reported with Xcopri. These include:

If you develop serious side effects while taking Xcopri, 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.

* To learn more about this side effect, see the “Side effects explained” section below.
† Withdrawal symptoms are side effects that can happen when you stop taking a drug your body is used to.

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Get answers to some frequently asked questions about Xcopri’s side effects.

How do side effects of Xcopri compare with those of Vimpat?

Xcopri and Vimpat are both types of antiepileptic drugs prescribed to treat focal (partial) onset seizures in adults. (Vimpat also has other approved uses.) Both drugs can cause many similar side effects but also a few different ones.

Some side effects both Xcopri and Vimpat may cause include:

  • double vision
  • headache
  • dizziness
  • sleepiness
  • eye-related side effects, including uncontrolled eye movements and double vision
  • suicidal thoughts or behaviors
  • nervous system side effects, such as problems with balance, coordination, and clear thinking

Xcopri may cause a high blood potassium level, a side effect not reported with Vimpat. On the other hand, Vimpat can cause heart block, also known as an atrioventricular (AV) block, which isn’t a side effect reported with Xcopri.

Talk with your doctor or pharmacist to learn more about how side effects of Xcopri and Vimpat compare.

Does Xcopri cause long-term side effects?

It’s possible. According to Xcopri’s studies, side effects that can occur even if you’ve taken the drug for a long time include nervous system side effects and hyperkalemia (high blood potassium level).

Talk with your doctor to learn more about possible side effects of Xcopri and how long they may last.

Learn more about some of the side effects Xcopri may cause.

Weight loss

Weight loss was a rare side effect reported in studies of Xcopri. In addition to weight loss, decreased appetite was also reported with this drug.

Although decreased weight was reported by people taking Xcopri, the drug should not be used for weight loss. It’s not approved for this purpose.

What might help

If you have concerns about your weight or appetite during Xcopri treatment, talk with your doctor. They’ll likely recommend switching you to another seizure medication if this side effect bothers you.

Nervous system side effects

In studies of Xcopri, serious nervous system side effects were rarely reported.

Your nervous system is made up of your brain, spinal cord, and a network of nerves running throughout your body. Symptoms of nervous system side effects caused by Xcopri include:

  • difficulty with coordination or walking
  • fatigue (low energy) and sleepiness
  • problems with concentration, memory, and clear thinking
  • vision problems, such as double vision

Nervous system side effects caused by Xcopri are dose-dependent. This means your risk of these effects increases as your dose increases.

Also, your risk of nervous system side effects from Xcopri is higher if you take other medications that can slow your nervous system. Examples include:

Consuming alcohol (if you drink) while taking Xcopri also increases this risk.

What might help

Call your doctor right away if you have symptoms of a nervous system side effect while taking this medication. Your doctor may recommend you stop taking Xcopri and can suggest other treatments for your condition.

Allergic reaction

Like most drugs, Xcopri can cause an allergic reaction in some people. These reactions were rare in studies.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

Rarely, Xcopri can also cause a type of allergic reaction called drug reaction with eosinophilia and systemic symptoms, also called DRESS syndrome. This reaction can affect numerous body organs, such as your liver and heart.

Symptoms of DRESS syndrome can include fever, skin rash, and swollen lymph nodes. Other symptoms vary depending on the parts of your body that are affected. For example, if this reaction affects your heart and causes myocarditis (inflammation of your heart muscle), you may experience:

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. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Xcopri, they’ll decide whether you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling, trouble breathing, or DRESS symptoms, call 911 or your local emergency number immediately. These symptoms could be life threatening and require urgent medical care.

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

Keeping track of side effects

During your Xcopri treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Xcopri affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Xcopri.

Warnings

Xcopri can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you.

Talk with your doctor about your health history before starting Xcopri. Be sure to tell them if any of the following factors apply to you:

Alcohol and Xcopri

You should not take Xcopri with alcohol without first speaking with your doctor.

Consuming alcohol while taking Xcopri raises your risk of nervous system side effects this drug may cause. (To learn more, see the ”Side effects explained” section above.)

If you have questions about consuming alcohol during Xcopri treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Xcopri

There’s limited information about the safety of Xcopri use during pregnancy and while breastfeeding.

Pregnancy

It’s not known whether it’s safe to take Xcopri during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before starting this medication.

If you take this drug while pregnant, consider signing up for The North American Antiepileptic Drug Pregnancy Registry by visiting the website or calling 888-233-2334. (Xcopri is an antiepileptic drug.) A pregnancy registry collects information about the safety of certain drugs when used during pregnancy.

Breastfeeding

It’s not known whether Xcopri affects breast milk production, passes through breast milk, or has any effects on a breastfed child. If you’re breastfeeding or planning to do so, talk with your doctor before starting this medication.

Xcopri is a Schedule V controlled substance, which means it has a small risk of misuse during treatment. Misuse refers to taking a drug in a way other than how it’s prescribed. Examples of misuse include taking the drug more often or at higher doses than recommended by your doctor.

You should take Xcopri only as your doctor has prescribed. Misuse increases the risk of overdose, which can lead to trouble breathing, coma, and even death.

Like most drugs, Xcopri can cause a number of side effects that range from mild to serious. But most are temporary and go away after a few days to weeks. If you have questions about side effects this drug can cause, talk with your doctor. Examples of questions to help get you started include:

  • Based on my medical history, how does my risk of side effects from Xcopri compare with that of other seizure treatments?
  • If I develop side effects from Xcopri but it’s working to manage my seizures, can you prescribe a lower dose for me?
  • If I’ve had memory problems as a side effect of other seizure drugs, do I have a higher risk of this side effect from Xcopri?

To learn more about Xcopri, see these articles:

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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.