Last updated on RxList: 2/3/2020
Xenazine Side Effects Center

What Is Xenazine?

Xenazine (tetrabenazine) is a monoamine depletory used to treat Huntington's chorea (uncontrolled muscle movements). Xenazine reduces the amount of certain chemicals in the body that are overly active in people with Huntington's disease.

What Are Side Effects of Xenazine?

Common side effects of Xenazine include:

  • insomnia,
  • drowsiness,
  • tired feeling,
  • nausea,
  • breast swelling or discharge,
  • sleep problems (insomnia),
  • feeling anxious or irritable, or
  • cold symptoms such as stuffy nose, sneezing, and sore throat.

Tell your doctor if you have serious side effects of Xenazine including:

  • extreme drowsiness;
  • mood or behavior changes, thoughts about suicide or hurting yourself;
  • restlessness, agitation, hyperactivity (mental or physical);
  • tremor (uncontrolled shaking), restless muscle movements in your eyes, tongue, jaw, or neck;
  • trouble swallowing;
  • problems with balance;
  • dizziness, fainting, fast or pounding heartbeat;
  • very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, feeling like you might pass out;
  • muscle pain, tenderness, or weakness with fever or flu symptoms and dark colored urine; or
  • urinating less than usual or not at all, swelling, weight gain, or shortness of breath.

Dosage for Xenazine

The starting dose of Xenazine is 12.5 mg per day given once in the morning. After one week, the dose is increased to 25 mg per day given as 12.5 mg twice a day.

What Drugs, Substances, or Supplements Interact with Xenazine?

Xenazine may interact with arsenic trioxide, droperidol, celecoxib, cimetidine, darifenacin, ropinirole, terbinafine, ADHD medications, antibiotics, antidepressants, anti-malaria medications, cancer medications, heart rhythm medications, HIV or AIDS medicines, medicine to treat or prevent nausea and vomiting, medicine to treat psychiatric disorders, migraine headache medicines, or narcotics. Tell your doctor all medications you use.

Xenazine During Pregnancy and Breastfeeding

During pregnancy, Xenazine should be taken only if prescribed. It is unknown if this drug passes into breast milk or if it could harm a nursing baby. Consult your doctor before breastfeeding.

Additional Information

Our Xenazine (tetrabenazine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


The abbreviated term ADHD denotes the condition commonly known as: See Answer
Xenazine Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

  • tremors, shaking, restless movement, problems with balance;
  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
  • trouble swallowing;
  • fast or pounding heartbeats;
  • a light-headed feeling, like you might pass out; or
  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats.

Common side effects may include:

  • drowsiness, tiredness;
  • depressed mood;
  • nausea; or
  • feeling anxious, agitated, or restless.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Xenazine (Tetrabenazine Tablets)


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Xenazine Professional Information


The following serious adverse reactions are described below and elsewhere in the labeling:

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

During its development, XENAZINE was administered to 773 unique subjects and patients. The conditions and duration of exposure to XENAZINE varied greatly, and included single and multiple dose clinical pharmacology studies in healthy volunteers (n=259) and open-label (n=529) and double-blind studies (n=84) in patients.

In a randomized, 12-week, placebo-controlled clinical trial of HD patients, adverse reactions were more common in the XENAZINE group than in the placebo group. Forty-nine of 54 (91%) patients who received XENAZINE experienced one or more adverse reactions at any time during the study. The most common adverse reactions were (over 10%, and at least 5% greater than placebo) were sedation/somnolence, fatigue, insomnia, depression, akathisia, and nausea.

Adverse Reactions Occurring in ≥ 4% Patients

The number and percentage of the most common adverse reactions that occurred at any time during the study in ≥ 4% of XENAZINE-treated patients, and with a greater frequency than in placebo-treated patients, are presented in Table 1.

Table 1: Adverse Reactions in a 12-Week, Double-Blind, Placebo-Controlled Trial in Patients with Huntington’s Disease

Adverse Reactionm XENAZINE
n = 54 %
n = 30 %
Sedation/somnolence 31 3
Insomnia 22 0
Depression 19 0
Anxiety/anxiety aggravated 15 3
Irritability 9 3
Decreased appetite 4 0
Obsessive reaction 4 0
Akathisia 19 0
Balance difficulty 9 0
Parkinsonism/bradykine sia 9 0
Dizziness 4 0
Dysarthria 4 0
Unsteady gait 4 0
Headache 4 3
Nausea 13 7
Vomiting 6 3
Fatigue 22 13
Fall 15 13
Laceration (head) 6 0
Ecchymosis 6 0
Upper respiratory tract infection 11 7
Shortness of breath 4 0
Bronchitis 4 0
Dysuria 4 0

Dose escalation was discontinued or dosage of study drug was reduced because of one or more adverse reactions in 28 of 54 (52%) patients randomized to XENAZINE. These adverse reactions consisted of sedation (15), akathisia (7), parkinsonism (4), depression (3), anxiety (2), fatigue (1) and diarrhea (1). Some patients had more than one AR and are, therefore, counted more than once.

Adverse Reactions Due to Extrapyramidal Symptoms

Table 2 describes the incidence of events considered to be extrapyramidal adverse reactions which occurred at a greater frequency in XENAZINE-treated patients compared to placebo-treated patients.

Table 2: Adverse Reactions Due to Extrapyramidal Symptoms in a 12-Week, Double-Blind, Placebo-Controlled Trial in Patients with Huntington’s disease

n = 54%
n = 30%
Akathisia 1 19% 0
Extrapyramidal event 2 15% 0
Any extrapyramidal event 33% 0
1Patients with the following adverse event preferred terms were counted in this category: akathisia, hyperkinesia, restlessness.
2Patients with the following adverse event preferred terms were counted in this category: bradykinesia, parkinsonism, extrapyramidal disorder, hypertonia.

Patients may have had events in more than one category.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of XENAZINE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Nervous system disorders: tremor

Psychiatric disorders: confusion, worsening aggression

Respiratory, thoracic and mediastinal disorders: pneumonia

Skin and subcutaneous tissue disorders: hyperhidrosis, skin rash

Read the entire FDA prescribing information for Xenazine (Tetrabenazine Tablets)

© Xenazine Patient Information is supplied by Cerner Multum, Inc. and Xenazine Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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