Valbenazine for Tardive Dyskinesia | FDA Approval

The U.S. Food and Drug Administration today approved Ingrezza (valbenazine) capsules to treat adults with tardive dyskinesia. This is the first drug approved by the FDA for this condition.

Tardive dyskinesia is a serious side effect sometimes seen in patients who have been treated with antipsychotic medications, especially the older medications, for long periods to treat chronic conditions, such as schizophrenia and bipolar disorder. Tardive dyskinesia can also occur in patients taking antipsychotic medications for depression and certain medications for gastrointestinal disorders and other conditions. It is unclear why some people who take these medications develop tardive dyskinesia yet others do not.

Valbenazine is known to cause reversible reduction of dopamine release by selectively inhibiting pre-synaptic human vesicular monoamine transporter type 2 (VMAT2). In vitro, valbenazine shows great selectivity for VMAT2 and little to no affinity for VMAT1 or other monoamine receptors. Although the exact cause of tardive dyskinsia is unknown, it is hypothesized that it may result from neuroleptic-induced dopamine hypersensitivity. By selectively reducing the ability of VMAT2 to load dopamine into synaptic vesicles, the drug reduces overall levels of available dopamine in the synaptic cleft, ideally alleviating the symptoms associated with dopamine hypersensitivity. The importance of valbenazine selectivity inhibiting VMAT2 over other monoamine transporters is that VMAT2 is mainly involved with the transport of dopamine, and to a much lesser extent other monoamines such as norepinephrine, serotonin, and histamine. This selectivity is likely to reduce the likelihood of “off-target” adverse effects which may result from the upstream inhibition of these other monoamines.

Vesicular Monoamine Transporter 2

 

VMAT2 inhibition

Read more about it here.

Older VAMP2 inhibitor: Tetrabenazine

Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorders. On August 15, 2008, the U.S. Food and Drug Administration approved the use of tetrabenazine to treat chorea associated with Huntington’s disease. Although other drugs had been used “off label,” tetrabenazine was the first approved treatment for Huntington’s disease in the U.S. The compound has been known since the 1950s.

Drugs<>Therapeutics<>Big Pharma
impas Natesh Prabhu Administrator & Chief Editor
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