Xenazine (tetrabenazine) is a brand-name drug that’s prescribed for chorea associated with Huntington’s disease in adults. It comes as an oral tablet that’s typically taken two or three times per day.

Xenazine belongs to a drug class called vesicular monoamine transporter 2 (VMAT2) inhibitors. This drug is available in a generic version.

Keep reading for specific information about the dosage of Xenazine, including its strengths and how to take the medication. For a comprehensive look at Xenazine, see this article.

Note: This article describes typical dosages for Xenazine provided by the drug’s manufacturer. When taking Xenazine, always follow the dosage prescribed by your doctor.

If you have thoughts of suicide during Xenazine treatment, call 911 or your local emergency number. In the United States, you can also call the Suicide and Crisis Lifeline at 988 or text HOME to the Crisis Textline at 741741. You can also refer to this article for ways to seek support.

The typically recommended dosages for Xenazine are described below.

Xenazine form

Xenazine comes as an oral tablet.

Xenazine strengths

Xenazine comes in two strengths: 12.5 milligrams (mg) and 25 mg.

Typical dosages

Typically, your doctor will start by prescribing you a low dosage. Then, they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly prescribed or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosage for chorea associated with Huntington’s disease

Doctors may prescribe Xenazine to treat chorea associated with Huntington’s disease. Chorea is a neurological condition that causes involuntary, unpredictable muscle movement.

If your doctor prescribes Xenazine for your chorea, your starting dosage will likely be 12.5 mg taken once per day. Typically, you’ll take this in the morning.

After 1 week, your doctor may recommend increasing your dosage to 12.5 mg twice per day. If necessary, they may increase your dose once per week until they find the dose that’s right for you. If your total daily dose is more than 37.5 mg, your doctor will recommend taking the medication three times per day.

If you need to take more than 50 mg of Xenaxine per day, your doctor will likely order a test to determine how fast your body processes drugs. The results of this test will help your doctor determine a safe maximum dosage for you. Depending on how quickly your body processes drugs, your maximum recommended dosage may be 50 or 100 mg.

For more information about your specific dosage, talk with your doctor.

Long-term treatment

Xenazine is meant to be taken as a long-term treatment. If you and your doctor determine that it’s safe and effective for you, you’ll likely take it long term.

Before you start taking Xenazine, your doctor will discuss your treatment plan with you.

The Xenazine dosage your doctor prescribes will depend on several factors. These include:

  • how your body responds to Xenazine
  • other medications you take
  • the severity of the condition you’re taking Xenazine to treat
  • side effects you may experience with Xenazine

Dosage adjustments

Your doctor may need to adjust your dosage if you take certain medications, such as strong CYP2D6 inhibitors.* These drugs can affect the level of Xenazine in your body.

Your doctor may also adjust your dose based on how well your body metabolizes drugs. If you need more than 50 mg of Xenazine per day, your doctor will order a lab test to determine this. The results of this lab test will determine the best dose for you.

If you experience side effects after a dosage increase, your doctor may lower your dose or discontinue treatment. They may also recommend other medications to help manage certain side effects.

Be sure to tell your doctor about all medications you take and any health conditions you may have.

* CYP2D6 is an enzyme (a type of protein) in the liver that breaks down medications.

Xenazine comes as an oral tablet that you swallow whole. Do not crush, chew, or place the tablet in water. The 25-mg tablet can be split into equal halves. You may take your dose with or without food.

If you have trouble swallowing tablets, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.


Some pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Xenazine in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Xenazine, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose and take your next scheduled dose. Do not take two doses to make up for the missed one. If you’re not sure whether you should take a missed dose or skip it, talk with your doctor or pharmacist.

If you miss a dose of Xenazine, your chorea symptoms may worsen or return within 12–18 hours of your last dose.

If you miss more than 5 days of Xenazine in a row, talk with your doctor. They may have you start taking the drug again at a lower dose and slowly increase the dose over time. Do not start taking your regular dose again without first talking with your doctor.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.

It’s important that you do not take more Xenazine than your doctor prescribes. For some medications, taking more than the recommended amount may lead to harmful effects or overdose.

Symptoms of an overdose

Overdose symptoms of Xenazine can include:

If you take more than the recommended amount of Xenazine

Call your doctor right away if you believe you’ve taken too much Xenazine. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

Below are some frequently asked questions about Xenazine.

Can Xenazine be used for tardive dyskinesia? If so, what’s the dosage?

No, Xenazine isn’t approved to treat tardive dyskinesia. It’s approved to treat Huntington’s chorea, which is a different type of dyskinesia.

Because Xenazine isn’t used for tardive dyskinesia, the drug’s manufacturer doesn’t provide recommended dosages for this use.

However, similar drugs are approved to treat tardive dyskinesia, including deutetrabenazine (Austedo).

If you have questions about managing your condition, talk with your doctor. They can recommend the right treatment options for you. To learn more about the differences between chorea and other types of dyskinesia, see this article.

What is the recommended maximum dosage of Xenazine?

The maximum dosage of Xenazine that the manufacturer recommends is 100 mg. However, the maximum dosage that’s safe for you will depend on how quickly your body metabolizes drugs. Based on this, your maximum dosage could be 50 or 100 mg.

If you have questions or concerns about your dosage of Xenazine, talk with your doctor or pharmacist. If it seems like you need a higher dosage, ask your doctor whether a dosage increase is right for you. Do not increase your dosage unless your doctor recommends doing so.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Xenazine for you, they’ll prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes.

As with any drug, never change your dosage of Xenazine without your doctor’s recommendation. If you have questions about the dosage of Xenazine that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Xenazine. These additional articles might be helpful:

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.