Chorea Symptoms: Chorea is a significant symptom for many Huntington's people that can greatly interfere with walking, talking, reading and other activities of daily life. Because it is the most visible symptom, chorea often causes social isolation both for the person and their families. More on the impact of chorea

Chorea Treatments: There are several types of drugs that are used to treat chorea. These include: antipsychotic drugs like Haldol® or Zyprexa®, and a newer drug aripiprazole (Abilify®), glutamate-blocker drugs like amantadine , and tetrabenazine which depletes dopamine. With the use of any of these drugs, it is important to be aware of side effects. It is important to visit your doctor on a regular basis so that the best dosage is found that balances benefit and side effects of the chosen drug.

Antipsychotic drugs are frequently used. Zyprexa® (olanzapine) and Risperdal® (risperidone) are most commonly used by Huntington's experts although Haldol® (haloperidol) is commonly used if cost is a major consideration. Haldol®, though thought to be effective, has more longer term side effects than the newer antipsychotics. There are no large studies that give evidence that any antipsychotic drug is better than another HD. However there is a small study that suggests that relatively new antipsychotic aripiprazole (Abilify®) is as effective as tetrabenazine for the treatment of chorea but has fewer side effects [Brusa L 2009]. It is important to see your physician on an ongoing basis to check for side effects. See Antipsychotic Fact Page for more information on these drugs.

Glutamate blocking drugs: The most frequently prescribed drug from this class includes amantadine. In clinical practice, most Huntington specialists believe this drug has only limited and short-term benefits.

Dopamine depleting drugs: Tetrabenazine (Nitoman®, Xenazine®) is the only drug in this class and is now FDA approved for use in the treatment of chorea in HD.

Commonly Used Chorea Medications

Amantadine (Symmetrel®): Studies of this drug for chorea have given variable results. One study found chorea benefit in a two week trial at 400 mg/day [Verhagen Metman L 2002]. Another study using intravenous drug was also positive [Lucetti C 2003]. However, a later two week placebo controlled study of 24 patients using 300 mg/day found no positive effect for chorea [O'Suilleabhain P 2003].

Amantadine dosage begins at 100 mg per day, and is increased to 300-400 mg total dose. Larger doses should be split and taken twice a day. Side effects most often include low blood pressure, nausea, insomnia, agitation, and headache.

Tetrabenazine (Nitoman® in Canada and some European countries; Xenazine® in the U.S. and some European countries). This drug was shown to decrease chorea in a large placebo controlled clinical trial for the short term [Huntington Study Group 2006]. A subsequent study has shown that chorea benefit continues long term. Side effects include sleepiness, insomnia, anxiety, and depression. This drug is now FDA approved in the United States.

Because of the high risk of serious depression and even suicide with this drug, I recommend the judicious use of antidepressants. It is known that tetrabenazine decreases levels of serotonin and norepinephrine, both of which are necessary for maintaining healthy mood.

Tetrabenazine dosing should start at 12.5 mg once or twice a day, and then increase by 12.5 mg per week until chorea decreases, or side effects occur. When on this drug it is important to see your doctor regularly to assess for depression and other side effects.

References

Brusa L, Orlacchio A, Moschella V, Iani C, Bernardi G, Mercuri NB. Treatment of the symptoms of Huntington's disease: preliminary results comparing aripiprazole and tetrabenazine. Mov Disord. 2009 Jan 15;24(1):126-9. doi: 10.1002/mds.22376. PubMed abstract

Verhagen Metman L, Morris MJ, Farmer C, Gillespie M, Mosby K, Wuu J, Chase TN. Huntington's disease: a randomized, controlled trial using the NMDA-antagonist amantadine. Neurology. 2002 Sep 10;59(5):694-9. PubMed abstract

Lucetti C, Del Dotto P, Gambaccini G, Dell' Agnello G, Bernardini S, Rossi G, Murri L, Bonuccelli U. IV amantadine improves chorea in Huntington's disease: an acute randomized, controlled study. Neurology. 2003 Jun 24;60(12):1995-7. PubMed abstract

O'Suilleabhain P, Dewey RB Jr. A randomized trial of amantadine in Huntington disease. Arch Neurol. 2003 Jul;60(7):996-8. PubMed abstract

Huntington Study Group. Tetrabenazine as antichorea therapy in Huntington disease: a randomized controlled trial. Neurology. 2006 Feb 14;66(3):366-72. PubMed abstract