Nuedexta (dextromethorphan/quinidine) is a prescription drug that’s used to treat pseudobulbar affect in adults. Nuedexta can cause side effects that range from mild to serious. Examples include dizziness and liver problems.

The active ingredients in Nuedexta are dextromethorphan hydrobromide and quinidine sulfate. (An active ingredient is what makes a drug work.) The drug comes as an oral capsule.

Keep reading to learn about the common, mild, and serious side effects that Nuedexta 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 Nuedexta treatment. Examples of the drug’s commonly reported side effects include:

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

Mild side effects have been reported with Nuedexta. 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 Nuedexta unless your doctor recommends it.

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

* An allergic reaction is possible after taking Nuedexta, but this side effect wasn’t reported in studies. To learn more, see the “Side effects explained” section below.

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

If you develop serious side effects while taking Nuedexta, 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.

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 Nuedexta, visit MedWatch.

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

Is Nuedexta safe for older adults?

Yes, Nuedexta is considered safe for older adults (ages 65 years and over). In studies of Nuedexta, there was no evidence of side effects occurring more often in older adults compared with younger adults.

But in general, older adults may be more likely to have certain health conditions, such as heart problems. These conditions could increase the risk of side effects from Nuedexta.

Due to this risk, doctors may prescribe a lower dose of Nuedexta for older adults when they start treatment. The doctor may then slowly increase the dosage over time to reduce the risk of side effects. For details about Nuedexta’s dosage, see this article.

To learn more about Nuedexta and possible age-related side effects, talk with your doctor or pharmacist.

Can Nuedexta cause weight gain?

It’s not likely. Weight gain wasn’t reported as a side effect in studies of Nuedexta.

If you’re concerned about weight gain with Nuedexta, talk with your doctor.

Does Nuedexta cause long-term side effects?

It’s unlikely. Long-term side effects weren’t reported in studies of Nuedexta.

If you’re concerned about possible long-term side effects from Nuedexta, talk with your doctor or pharmacist.

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

Dizziness

Dizziness was a common side effect reported in studies of Nuedexta. Dizziness may cause loss of balance and, in some cases, could lead to falls.

Certain factors can raise the risk of dizziness that leads to falls during Nuedexta treatment. These include having problems with walking and balance or a history of falling.

What might help

If you have dizziness during Nuedexta treatment, talk with your doctor. They can recommend tips for managing this side effect.

For example, your doctor may suggest sitting down and resting when you feel dizzy. They may also suggest that you avoid switching positions suddenly, such as going from sitting to standing too quickly.

You may also find it helpful to check out this article for tips on managing dizziness.

Liver problems

Nuedexta may cause liver problems in some people. Certain liver problems were more common than others in studies of Nuedexta.

For example, high levels of liver enzymes (proteins) were common. This can be a sign of liver damage. Hepatitis (inflammation of the liver) wasn’t reported in studies, but this side effect has been reported since quinidine* became available for use.

Liver problems may cause symptoms such as:

* Quinidine is one of the active ingredients in Nuedexta. An active ingredient is what makes a drug work.

What might help

If you have symptoms of liver problems during Nuedexta treatment, tell your doctor right away. They can order tests to check your liver function.

If the tests show that you have liver problems, your doctor will likely have you stop taking Nuedexta. They can recommend other ways to manage your condition.

Allergic reaction

Like most drugs, Nuedexta can cause an allergic reaction in some people. But this side effect wasn’t reported 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

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 Nuedexta, they’ll decide whether you should continue taking it.

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 Nuedexta, they may have you switch to a different treatment.

Keeping track of side effects

During Nuedexta 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 Nuedexta affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before taking Nuedexta.

Warnings

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

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

Alcohol and Nuedexta

You should not drink alcohol during your Nuedexta treatment until you know how the drug affects you.

This is because combining alcohol with Nuedexta could worsen some of the drug’s side effects. Examples include vomiting and dizziness.* Drinking large amounts of alcohol during your treatment can also increase the risk of liver problems* from Nuedexta. Because of this, it may be best to limit the amount of alcohol you consume while taking Nuedexta.

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

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

Pregnancy and breastfeeding with Nuedexta

It’s not known whether Nuedexta is safe to take during pregnancy or while breastfeeding. Before starting Nuedexta treatment, it’s important to talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed.

Like most drugs, Nuedexta can cause side effects that range from mild to serious. However, most are temporary and go away after a few days to weeks. If you have questions about side effects that Nuedexta can cause, talk with your doctor.

Examples of questions to help get you started include:

  • Could any other medications I take increase my risk of side effects from Nuedexta?
  • Do any medical conditions I have increase my risk of side effects with this drug?
  • Are there any side effects of Nuedexta I should tell you about right away?

To learn more about Nuedexta, 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.