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Pivotal Study Results

Patients experienced significant chorea reductions as early as Week 3 with Xenazine^1,2

Proper dosing of Xenaxine involves careful titration of therapy to determine an individualized dose for each patient. When first prescribed, Xenazine therapy should should be titrated slowly over several weeks to allow the identification of a dose that both reduces chorea and is well tolerated. If adverse events such as akathisia, restlessness, parkinsonism, insomnia, anxiety, or intolerable sedation occur, titration should be stopped and the dose should be reduced.

For daily doses up to 50 mg, the maximum recommended single dose is 25 mg.¹

Patients who appear to require doses greater than 50 mg/day should be genotyped for CYP2D6.¹

Noticeable improvements in CGI

Physicians rated 69% of patients receiving Xenazine as significantly improved on the Clinical Global Impression (CGI) Global Improvement scale compared with 24% of patients receiving placebo (p=0.0063).²

CGI was the secondary endpoint ²

In general, measures of functional capacity and cognition showed no difference between Xenazine and placebo. However, 1 functional measure (Part 4 of the UHDRS) showed a decrement for patients treated with Xenazine compared with placebo, a difference that was nominally statistically significant.¹

A 3-item cognitive battery specifically developed to assess cognitive function in patients with HD (Part 2 of the UHDRS) also showed a decrement for patients treated with Xenazine compared with placebo, but the difference was not statistically significant.¹

Pivotal study exploratory outcomes⁴

Xenazine had no significant impact on the UHDRS Total Motor Scores
Xenazine had an adverse impact on the UHDRS Functional Checklist, with the Xenazine group worsening by 0.8 units and the placebo group improving by 0.4 units (p=0.02)
Xenazine had no significant impact on UHDRS gait assessment, UHDRS parkinsonism score, or any other exploratory outcome measures (Total Functional Capacity, Functional Impact Scale, Independence Scale)
Xenazine had no significant impact on the Barnes Akathisia Scale, UHDRS Behavioral Assessment, Unified Parkinson’s Disease Rating Scale (UPDRS) swallowing, or UPDRS speech items
Xenazine had an adverse impact on Stroop word reading but not on other UHDRS measures of cognitive function
Xenazine and placebo had an improvement on the 17-itme HAM-D, but results favored placebo over Xenazine

Sources:

Xenazine [package insert]. Deerfield, IL: Lundbeck Inc; 2009.
Data on file, Lundbeck Inc.
Data on file, Lundbeck Inc.
Huntington Study Group. Tetrabenazine as antichorea therapy in Huntington disease: a randomized controlled trial. Neurology. 2006; 66(3):366-372.
Guy W, ed. Clinical Global Impression (CGI). ECDEU Assessment Manual for Psychopharmacology. Rockville, MD: US Department of Health, Education, and Welfare; 1976.

XENAZINE® (tetrabenazine) Tablets

Indications and Usage:

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

Important Safety Information:

WARNING: DEPRESSION AND SUICIDALITY

See full prescribing information for complete boxed warning.

Increases the risk of depression and suicidal thoughts and behavior (suicidality) in patients with Huntington’s disease.
Balance risks of depression and suicidality with the clinical need for control of choreiform movements when considering the use of XENAZINE.
Monitor patients for the emergence or worsening of depression, suicidality, or unusual changes in behavior.
Inform patients, caregivers and families of the risk of depression and suicidality and instruct to report behaviors of concern promptly to the treating physician.
Exercise caution when treating patients with a history of depression or prior suicide attempts or ideation.
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 (MAOIs) or reserpine. XENAZINE should not be used in combination with an MAOI, or within a minimum of 14 days of discontinuing therapy with an MAOI. At least 20 days should elapse after stopping reserpine before starting XENAZINE.

Prescribers should periodically re-evaluate the need for XENAZINE in their patients by assessing the beneficial effect on chorea and possible adverse effects including worsening mood, cognition, rigidity and functional capacity. 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. Do not exceed 50 mg/day or 25 mg/dose if XENAZINE is administered with a strong CYP2D6 inhibitor.

Neuroleptic malignant syndrome (NMS), akathisia, agitation, parkinsonism, dysphagia and aspiration pneumonia, 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. Alcohol or other sedating drugs can worsen sedation and somnolence.

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.

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.

Pivotal Study Results

Patients experienced significant chorea reductions as early as Week 3 with Xenazine1,2

For daily doses up to 50 mg, the maximum recommended single dose is 25 mg.1

Patients who appear to require doses greater than 50 mg/day should be genotyped for CYP2D6.1