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Xenazine Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 6/16/2015

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

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. 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. 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 breast-feeding.

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.

What is Patient Information in Detail?

Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.

Xenazine in Detail - Patient Information: Side Effects

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

Stop using tetrabenazine and call your doctor at once if you have a serious side effect such as:

  • extreme drowsiness;
  • mood or behavior changes, thoughts about suicide or hurting yourself;
  • feeling restless, agitated, or hyperactive (mentally or physically);
  • 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, feeling short of breath.

Less serious side effects may include:

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

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)

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Xenazine FDA Prescribing Information: Side Effects
(Adverse Reactions)


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)

Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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