Tetrabenazine as anti-chorea therapy in Huntington Disease: An open-label continuation study. Huntington Study Group/TETRA-HD Investigators

BMC Neurology (Impact Factor: 2.04). 12/2009; 9(1):62. DOI: 10.1186/1471-2377-9-62
Source: PubMed


Tetrabenazine (TBZ) selectively depletes central monoamines by reversibly binding to the type-2 vesicular monoamine transporter. A previous double blind study in Huntington disease (HD) demonstrated that TBZ effectively suppressed chorea, with a favorable short-term safety profile (Neurology 2006;66:366-372). The objective of this study was to assess the long-term safety and effectiveness of TBZ for chorea in HD.
Subjects who completed the 13-week, double blind protocol were invited to participate in this open label extension study for up to 80 weeks. Subjects were titrated to the best individual dose or a maximum of 200 mg/day. Chorea was assessed using the Total Maximal Chorea (TMC) score from the Unified Huntington Disease Rating Scale.
Of the 75 participants, 45 subjects completed 80 weeks. Three participants terminated due to adverse events (AEs) including depression, delusions with associated previous suicidal behavior, and vocal tics. One subject died due to breast cancer. The other 26 subjects chose not to continue on with each ensuing extension for various reasons. When mild and unrelated AEs were excluded, the most commonly reported AEs (number of subjects) were sedation/somnolence (18), depressed mood (17), anxiety (13), insomnia (10), and akathisia (9). Parkinsonism and dysarthria [corrected] scores were significantly increased at week 80 compared to baseline. At week 80, chorea had significantly improved from baseline with a mean reduction in the TMC score of 4.6 (SD 5.5) units. The mean dosage at week 80 was 63.4 mg (range 12.5-175 mg).
TBZ effectively suppresses HD-related chorea for up to 80 weeks. Patients treated chronically with TBZ should be monitored for parkinsonism, dysphagia and other side effects including sleep disturbance, depression, anxiety, and akathisia. registration number (initial study): NCT00219804.

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    • "TBZ can induce symptoms of depression, including fatigue, in people who receive it as a treatment for Huntington's disease (Frank 2009, 2010; Guay 2010), and can induce behavioral signs of depression in animal models such as forced swim and tail suspension tests (Preskorn et al. 1984; Kent et al. 1986; Wang et al. 2010). Recently, TBZ was reported to reduce lever pressing and increase chow intake in rats responding on concurrent lever pressing/chow feeding choice procedures (Nunes et al. 2013b; Randall et al. 2014a). "
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    ABSTRACT: Rationale Depressed people show effort-related motivational symptoms, such as anergia, retardation, lassitude, and fatigue. Animal tests can model these motivational symptoms, and the present studies characterized the effort-related effects of the vesicular monoamine transport (VMAT-2) inhibitor tetrabenazine. Tetrabenazine produces depressive symptoms in humans and, at low doses, preferentially depletes dopamine. Objectives The current studies investigated the effects of tetrabenazine on effort-based decision making using the T-maze barrier task. Methods Rats were tested in a T-maze in which the choice arms of the maze contain different reinforcement densities, and under some conditions, a vertical barrier was placed in the high-density arm to provide an effort-related challenge. The first experiment assessed the effects of tetrabenazine under different maze conditions: a barrier in the arm with 4 food pellets and 2 pellets in the no barrier arm (4-2 barrier), 4 pellets in one arm and 2 pellets in the other with no barrier in either arm (no barrier), and 4 pellets in the barrier arm with no pellets in the other (4-0 barrier). Results Tetrabenazine (0.25-0.75 mg/kg IP) decreased selection of the high cost/high reward arm when the barrier was present, but had no effect on choice under the no barrier and 4-0 barrier conditions. The effects of tetrabenazine on barrier climbing in the 4-2 condition were reversed by the adenosine A2A antagonist MSX-3 and the catecholamine uptake inhibitor and antidepressant bupropion. Conclusions These studies have implications for the development of animal models of the motivational symptoms of depression and other disorders.
    Full-text · Article · Oct 2014 · Psychopharmacology
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    • "We also showed that this small group of TBZ responders did not exhibit parkinsonian gait changes. This study confirms previous work demonstrating a significant improvement in UHDRS total motor and chorea scores on-TBZ than off- TBZ [6] [7] "
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    ABSTRACT: Chorea may contribute to balance problems and walking difficulties that lead to higher fall rates in individuals with Huntington’s disease (HD). Few studies have examined the effects of tetrabenazine (TBZ), an anti-choreic drug, on function and mobility in HD. The purpose of this study was to compare: 1) gait measures in forward walking, 2) balance and mobility measures, and 3) hand and forearm function measures on and off TBZ. We hypothesized that use of TBZ would improve gait, transfers and hand and forearm function. Eleven individuals with HD on stable doses of TBZ were evaluated while off medication and again following resumption of medication. Significant improvements were found on the Unified Huntington’s Disease Rating Scale (UHDRS) motor scores, Tinetti Mobility Test (TMT) total (t = 4.20, p = 0.002) and balance subscale (t = − 4.61, p = 0.001) scores, and the Five Times Sit-to-Stand test (5TSST, t = 3.20, p = .009) when on-TBZ compared to off-TBZ. Spatiotemporal gait measures, the Six Condition Romberg test, and UHDRS hand and forearm function items were not changed by TBZ use. Improved TMT and 5TSST performance when on drug indicates that TBZ use may improve balance and functional mobility in individuals with HD.
    Full-text · Article · Oct 2014 · Journal of the Neurological Sciences
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    • "The same group of study participants was given the opportunity to participate in an open-label extension study. Subjects who completed the 13-week, double-blind protocol were invited to participate in this open-label extension study for up to 80 weeks.16 Of the 75 participants, 45 subjects completed 80 additional weeks of treatment with TBZ. "
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    ABSTRACT: Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by progressive involuntary movements, neuropsychiatric disturbances, and cognitive impairment. The use of tetrabenazine (TBZ), a specific inhibitor of vesicular monoamine transporter, is approved for chorea in HD patients. We aimed to review the medical literature concerning the efficacy and tolerability of TBZ in the treatment of HD patients and to report our personal experience about TBZ use in a cohort of HD patients. We searched PubMed (1960 to July 2010) using the following keywords: "tetrabenazine" + "huntington's disease + chorea". We included randomized controlled trials, open-label trials, and retrospective studies. We excluded case reports and studies conducted on fewer than 20 patients. In addition, we retrospectively evaluated 2 years' follow-up of TBZ treatment on motor and cognitive performances and functional abilities in 28 HD patients, compared with 10 patients treated by other neuroleptics (clotiapine). Only four papers fulfilled the requested criteria. In the first study, which included 84 randomized outpatients, TBZ showed a significant improvement of chorea compared with placebo. In the open-label study extension, TBZ confirmed its efficacy on chorea, with a frequent occurrence of withdrawals due to side effects. In a retrospective study of long-term efficacy, 63 patients under TBZ therapy for an average period of 34 months showed a stable effect on chorea, despite a slight reduction of effect over time. In a telephone survey conducted on a total of 118 patients affected by different movement disorders, TBZ showed the most favorable effect for the 28 included HD patients. Our HD patients showed a slight deterioration of motor performances over time that was nonsignificant compared with TBZ or clotiapine treatments. Despite the fact that the global effect of TBZ seems positive in HD, more attention on evaluating symptomatic treatments for cognitive and psychiatric deterioration as well as motor deterioration would alleviate this devastating disorder until a neuroprotective treatment becomes available.
    Full-text · Article · Mar 2011 · Therapeutics and Clinical Risk Management
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