See the DrugPatentWatch profile for Tetrabenazine
How Does Tetrabenazine Work?
Tetrabenazine is a medication used to treat chorea associated with Huntington's disease. Its primary mechanism of action involves the depletion of monoamines, particularly dopamine, from nerve endings [1]. It achieves this by reversibly inhibiting the vesicular monoamine transporter 2 (VMAT2) [1].
What Does VMAT2 Inhibition Do?
VMAT2 is a protein responsible for packaging monoamine neurotransmitters, such as dopamine, serotonin, and norepinephrine, into vesicles within neurons [1]. By inhibiting VMAT2, tetrabenazine prevents these neurotransmitters from being stored in vesicles [1]. This leads to an increase in intraneuronal monoamine levels, which are then susceptible to enzymatic degradation, ultimately reducing the amount of neurotransmitter available for release into the synapse [1]. The depletion of dopamine, in particular, is believed to be responsible for tetrabenazine's therapeutic effect in reducing chorea [1].
How Long Does Tetrabenazine's Effect Last?
Tetrabenazine has a relatively short half-life, meaning it is eliminated from the body quickly [1]. However, its effects on dopamine depletion can be sustained through repeated dosing [1].
What Other Uses Does Tetrabenazine Have?
While primarily prescribed for chorea in Huntington's disease, tetrabenazine has also been used off-label to treat other hyperkinetic movement disorders, such as tardive dyskinesia [2].
Are There Alternatives to Tetrabenazine?
Another medication, deutetrabenazine, is a deuterium-modified analog of tetrabenazine that also inhibits VMAT2 but has a longer half-life and potentially different dosing requirements and side effect profiles [3]. Valbenazine is another VMAT2 inhibitor approved for the treatment of tardive dyskinesia [4].
What Are the Risks Associated with Tetrabenazine?
Tetrabenazine carries a boxed warning for depression and suicidal ideation and behavior [1]. Patients taking tetrabenazine should be monitored for these risks [1]. Other potential side effects include somnolence, parkinsonism, and akathisia [1].
When Did Tetrabenazine's Patent Last Expire?
Information on specific patent expiry dates for tetrabenazine is not provided, but details on drug patents and exclusivity periods can be found on DrugPatentWatch.com [5].
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**Sources
1. https://www.drugpatentwatch.com/drug/tetrabenazine
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4929751/
3. https://www.drugpatentwatch.com/drug/deutetrabenazine
4. https://www.drugpatentwatch.com/drug/valbenazine
5. https://www.drugpatentwatch.com/