Tetrabenazine is a drug for the symptomatic treatment of hyperkinetic movement disorders. It is sold under the brand names Nitoman and Xenazine among others. On August 15, 2008, the US Food and Drug Administration approved the use of tetrabenazine to treat chorea associated with Huntington disease. Pharmacologically, tetrabenazine is a reversible inhibitor of the vesicular monoamine transporter 2 VMAT2 that reduces presynaptic uptake and storage of monoamines, most notably dopamine, resulting in decreased synaptic dopamine availability; it is rapidly absorbed and extensively metabolized by hepatic CYP2D6 to active alpha and beta dihydrotetrabenazine metabolites which have longer apparent half lives than the parent compound. Clinically the product is dosed in divided administrations with typical adult maintenance ranges from 12.5 mg per day up to 100 mg per day depending on response and tolerability, with dose titration recommended and dose reduction advised for CYP2D6 poor metabolizers and significant hepatic impairment. Safety considerations include sedation, parkinsonism, akathisia, and mood effects including depression and suicidal ideation, and concomitant use with monoamine oxidase inhibitors and reserpine is contraindicated.
Parent: Tetrabenazine
Parent: Tetrabenazine
Parent: Tetrabenazine
Parent: Tetrabenazine
Parent: Tetrabenazine
Parent: Tetrabenazine
Parent: Tetrabenazine / Valbenazine
![(2S,3S,11bS)-3-Isobutyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-ol](https://veeprho.com/wp-content/uploads/2026/04/2S3S11bS-3-Isobutyl-910-dimethoxy-1346711b-hexahydro-2H-pyrido21-aisoquinolin-2-ol-164104-49-8-VE0028700.png "(2S,3S,11bS)-3-Isobutyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro-2H-pyrido[2,1-a]isoquinolin-2-ol")
Parent: Tetrabenazine/ Valbenazine
![1,3,4,6,7,11b-Hexahydro-9,10-dimethoxy-1-(2-methylpropyl)-2H-benzo[a]quinolizine-2-one](https://veeprho.com/wp-content/uploads/2026/05/1346711b-Hexahydro-910-dimethoxy-1-2-methylpropyl-2H-benzoaquinolizine-2-one-99672-64-7-VE0026300-825f.png "1,3,4,6,7,11b-Hexahydro-9,10-dimethoxy-1-(2-methylpropyl)-2H-benzo[a]quinolizine-2-one")
Parent: Tetrabenazine
![3-Isobutyl-9,10-dimethoxy-3,4,6,7-tetrahydro-2H-pyrido[2,1-a]isoquinolin-2-one](https://veeprho.com/wp-content/uploads/2026/05/3-Isobutyl-910-dimethoxy-3467-tetrahydro-2H-pyrido21-aisoquinolin-2-one-100322-43-8-VE0027568-ef19.png "3-Isobutyl-9,10-dimethoxy-3,4,6,7-tetrahydro-2H-pyrido[2,1-a]isoquinolin-2-one")
Parent: Tetrabenazine
Parent: Tetrabenazine
Manufacture and quality control of tetrabenazine API and finished products monitor related substances by stability indicating HPLC and orthogonal methods such as LC-MS for identity. Typical related compounds and degradation products reported in production and stability studies include alpha-dihydrotetrabenazine and beta-dihydrotetrabenazine (the primary active metabolites), N-desmethyl tetrabenazine, tetrabenazine N-oxide, and low-level oxidative or dehydrogenated derivatives; manufacturers commonly specify individual identified related substances at not more than 0.5 percent w w for each named impurity, unspecified individual impurities at or below 0.05 to 0.1 percent w w, and total impurities not to exceed approximately 1.0 to 2.0 percent w w, consistent with ICH Q3A and Q3B risk-based thresholds and qualification requirements; final product specifications and analytical acceptance criteria are product and regulatory filing dependent, and identification and qualification of impurities above reporting thresholds is performed using LC-MS and NMR as needed.
Tetrabenazine is prescribed for symptomatic control of hyperkinetic movement disorders, principally chorea associated with Huntington disease, and for other severe, disabling hyperkinetic conditions when reduction of excessive involuntary movements is required.
No, tetrabenazine is not classified as an antipsychotic. It is a VMAT2 inhibitor that reduces presynaptic monoamine storage, whereas antipsychotics primarily block postsynaptic dopamine receptors.
No, tetrabenazine is not a monoamine oxidase inhibitor. Because it alters monoamine handling, coadministration with MAO inhibitors is contraindicated due to risk of adverse interactions.
Tetrabenazine is not primarily a sedative, but drowsiness and somnolence are common adverse effects; patients should be cautioned about operating machinery or driving until they know how the drug affects them.
