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Prescribing Xenazine Medication Assistance Program

Huntington Study Group (HSG) Trial


Xenazine has been proven effective for the treatment of chorea associated with HD.1

A multicenter, prospective, double-blind, placebo-controlled study of patients with HD conducted at 16 HSG sites in the United States:1,2

chart

Five patients discontinued Xenazine because of AEs, 4 of them serious: complicated fall, suicide, breast cancer (non-drug related preexisting condition), restlessness/suicidal ideation, and akathisia

The UHDRS is a valid research tool3

In the Xenazine U.S. pivotal study (HSG Trial), chorea was measured by the investigators using the Motor Function subsection (item 12) of the UHDRS. The Total Chorea Score was measured by the investigators using a 5-point scale with a score range from 0 to 28.1

Sources:

  • Xenazine [package insert]. Deerfield, IL: Lundbeck Inc; 2009.
  • Huntington Study Group. Tetrabenazine as antichorea therapy in Huntington disease: a randomized controlled trial. Neurology. 2006; 66(3):366-372.
  • Huntington Study Group. Unified Huntington's disease rating scale: reliability and consistency. Mov Dis. 1996; 11(2):136-142.
  • Phillips W, Barker R. The use of tetrabenazine in movement disorders. Adv ClinNeurosci Rehabil. 2005; 5(1):40-41.


XENAZINE® (tetrabenazine) Tablets

Indications and Usage:

Xenazine is indicated for the treatment of chorea associated with Huntington’s disease.

Important Safety Information:

DEPRESSION AND SUICIDALITY

XENAZINE can increase the risk of depression and suicidal thoughts and behavior (suicidality) in patients with Huntington’s disease. Anyone considering the use of XENAZINE must balance the risks of depression and suicidality with the clinical need for control of choreiform movements. Close observation of patients for the emergence or worsening of depression, suicidality, or unusual changes in behavior should accompany therapy. Patients, their caregivers, and families should be informed of the risk of depression and suicidality and should be instructed to report behaviors of concern promptly to the treating physician.

Particular caution should be exercised in treating patients with a history of depression or prior suicide attempts or ideation, which are increased in frequency in Huntington’s disease. XENAZINE is contraindicated in patients who are actively suicidal, and in patients with untreated or inadequately treated depression.

Xenazine is also contraindicated in patients who have impaired hepatic function or are taking monoamine oxidase inhibitors or reserpine. At least 20 days should elapse after stopping reserpine before starting Xenazine.

The need for therapy should be evaluated on an ongoing basis with the patient’s doctor. Xenazine should be titrated slowly over several weeks for a dose that is appropriate for each patient. Before a dose greater than 50 mg is administered, the patient’s CYP2D6 metabolizer status should be determined.

Neuroleptic malignant syndrome (NMS), akathisia, agitation, parkinsonism, dysphagia, and QT prolongation–related arrhythmias have been reported with use of Xenazine. Xenazine should not be used in combination with drugs known to prolong QTc (which in certain circumstances can lead to torsades de pointes and/or sudden death), in patients with congenital long QT syndrome, or in patients with a history of cardiac arrhythmias. A potentially irreversible syndrome of involuntary, dyskinetic movements called tardive dyskinesia (TD) may develop in patients treated with neuroleptic drugs. If signs and symptoms of TD appear in a patient treated with Xenazine, drug discontinuation should be considered. Adverse reactions associated with Xenazine, such as QTc prolongation, NMS, and extrapyramidal disorders, may be exaggerated by concomitant use of dopamine antagonists.

Xenazine elevates serum prolactin concentrations. Xenazine may induce sedation and somnolence (sleepiness or drowsiness) and may impair the ability to drive or operate dangerous machinery.

Some adverse events such as depression, fatigue, insomnia, sedation/somnolence, parkinsonism, and akathisia may be dose-dependent. If the adverse effect does not resolve or decrease, consideration should be given to lowering or discontinuing Xenazine. The most commonly reported adverse events with Xenazine compared to placebo were sedation/somnolence (31% vs 3%), fatigue (22% vs 13%), insomnia (22% vs 0%), depression (19% vs 0%), akathisia (19% vs 0%), anxiety (15% vs 3%), and nausea (13% vs 7%).

For more information, please see Full Prescribing Information, including Boxed Warning.

®Xenazine is a registered trademark of Biovail Laboratories International (Barbados) S.R.L.

©2009 Lundbeck Inc., Deerfield IL 60015. All rights reserved.

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The product information provided in this site is intended only for residents of the U.S. The health information contained herein is provided for educational purposes only and is not intended to replace discussions with a healthcare provider.