Prestwick Pharmaceuticals manufactured the Xenazine (Tetrabenazine) for Treatment of Chorea Associated with Huntington's disease. Xenazine is a highly selective and reversible dopamine depletor that works by inhibiting vesicular monoamine transporter Xenazine works by depleting the stores of certain chemicals called neurotransmitters within nerve cells of the brain. These neurotransmitters include dopamine, noradrenaline, and serotonin and are normally involved with the passage of messages between nerve cells in the brain and the normal functioning of the brain and nervous system.

Depleting the brain of these neurotransmitters can help control the movement disorders caused by diseases of the brain and nervous system, although the exact mechanism of action is not fully understood.

Xenazine is mainly used to control movement disorders associated with diseases of the brain and nervous system, such as Huntington's chorea, but it can also be used to control the movement disorders caused by antipsychotic medicines.

The older antipsychotic medicines such as chlorpromazine, flupentixol, and haloperidol can cause side effects involving involuntary movement of the tongue, face, mouth and jaw, which may sometimes be accompanied by involuntary movements of the arms and legs. If this is a disabling or socially embarrassing, and persists despite stopping or reducing the dose of the antipsychotic, the symptoms can be treated using Xenazine. can also be used if it is not possible to stop or change the antipsychotic drug.

Xenazine is also the first product for which an NDA has been filed in the U.S. for the treatment of chorea associated with Huntington's disease Chorea, a debilitating feature of a number of neurological diseases, is characterized by excessive, involuntary, and repetitive movements, which may involve the face, limbs, or the entire body. In Huntington's disease, it is the result of overactivity of the neurotransmitter dopamine.