Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorder and is marketed under the trade names Nitoman in Canada and Xenazine in New Zealand and some parts of Europe, and is also available in the USA as an orphan drug. On August 15, 2008 the U.S. Food and Drug Administration (FDA) approved the use of tetrabenazine to treat chorea associated with Huntington's disease (HD), the first in the US. The compound has been known since the 1950s.
§Pharmacology
Tetrabenazine works mainly as a VMAT-inhibitor, and as such promotes the early metabolic degradation of monoamines, in particular the neurotransmitter dopamine.
§Uses2>
Tetrabenazine is used as a treatment, but not as a cure, for hyperkinetic disorders such as:
- Huntington's Disease â€" specifically the chorea associated with it
- Tourette syndrome and other tic disorders
- Tardive dyskinesia, a serious and sometimes irreversible side effect of long-term use of many antipsychotics, mainly typical antipsychotics
- Hemiballismus, spontaneous flinging limb movements due to contra-lateral subthalamic nucleus damage
§Side effects
Some of these include:
- Akathisia (aka "restless pacing" â€" an inability to keep still, with intense anxiety when forced to do so)
- Depression - the most common side effect, reported in roughly 15% of those who take the medication
- Dizziness, drowsiness, insomnia, fatigue, nervousness and anxiety
- parkinsonism
§Warnings
- Because of the relatively high incidence of depression, it has been recommended that people with a history of depression avoid taking tetrabenazine.
- The concomitant intake of MAO inhibitors is contraindicated.
§References
§External links
- NIMH Repository data sheet
- "Tetrabenazine" from HOPES: Huntington's Disease Outreach Project for Education at Stanford
- Detailed monograph on tetrabenazine on rxmed.com
- Information on tetrabenazine from netdoctor.co.uk