The Food and Drug Administration (FDA) on Friday approved tetrabenazine, marketed by Prestwick Pharmaceuticals under the Xenazine brand name, for the treatment of hyperkinetic movement disorder associated with Huntington disease, being the first treatment for the inherited disease's symptoms approved in the United States.

The uncontrolled movements, named chorea by the academic world, makes those suffering of Huntington disease often socially incompatible with their peers, forcing them to live as shut-ins.

Xenazine has already been approved in Canada, Europe and Australia. About 30,000 people in the United States are affected by the rare Huntington disease, which also leads to the impairing of mental abilities and, ultimately, death. However, tetrabenazine, as nearly all antipsychotics, has serious side effects which have to be carefully evaluated when prescribing the medication.

The drug inhibits the Vesicular Monoamine Transporter 2 or VMAT2, a protein which acts to transport dopamine and other neurotransmitters from cellular cytosol into synaptic vesicles. This enables the drug to tone down the patients' overactive neurological system.

Nancy Wexler, Ph.D., Higgins Professor of Neuropsychology in the departments of neurology and psychiatry at Columbia University and president of the Hereditary Disease Foundation, applauded FDA's decision, underlining that it will enable patients to control chorea, which often prevents them from walking, talking, working, watching television and other basic tasks.