Medicine guide

Tetrabenazine

25 mg · Tablet

Prescription only
Vesicular Monoamine Transporter 2 Inhibitor

Active substance: Tetrabenazine
Made by: Golden State Medical Supply, Inc.
Source: Official label

Quoted from the official source. Not yet reviewed by Mediclarum — the leaflet in your pack is authoritative.

At a glance

Quoted from the official label · 2025-10-13

What it is

Vesicular Monoamine Transporter 2 Inhibitor

Used for

Tetrabenazine tablets are indicated for the treatment of chorea associated with Huntington's disease.

The label’s usual adult dose

The 1 st week's starting dose is 12.5 mg daily; 2 nd week, 25 mg (12.5 mg twice daily); then slowly titrate at weekly intervals by 12.5 mg to a tolerated dose that reduces chorea.

( 2.2 , 5.3 ) Maximum daily dose in PMs: 50 mg with a maximum single dose of 25 mg.

Full directions ↓

Serious warning

DEPRESSION AND SUICIDALITY Tetrabenazine can increase the risk of depression and suicidal thoughts and behavior (suicidality) in patients with Huntington’s disease.

All warnings ↓

Good to know

Prescription only
FDA enforcement reports list no ongoing recall, and none from the last two years, for this product code · checked 2026-10-02

23other products contain Tetrabenazine — compare makers, forms and strengths

Every line above is selected, not written, from the official label. Nothing is reworded. DailyMed

What it is for

Tetrabenazine tablets are indicated for the treatment of chorea associated with Huntington's disease.
Tetrabenazine tablets are a vesicular monoamine transporter 2 (VMAT) inhibitor indicated for the treatment of chorea associated with Huntington's disease ( 1 )

From the official label · 2025-10-13 · DailyMed

How it works

From this product’s own US prescribing label.

The precise mechanism by which tetrabenazine exerts its anti-chorea effects is unknown but is believed to be related to its effect as a reversible depletor of monoamines (such as dopamine, serotonin, norepinephrine, and histamine) from nerve terminals.
Tetrabenazine reversibly inhibits the human vesicular monoamine transporter type 2 (VMAT2) (K i ≈ 100 nM), resulting in decreased uptake of monoamines into synaptic vesicles and depletion of monoamine stores.

Half-life17.5 h

Mostly cleared after≈ 4 daysfive half-lives — our arithmetic

How the body breaks it down

After oral administration, tetrabenazine is extensively hepatically metabolized, and the metabolites are primarily renally eliminated. α-HTBZ, β-HTBZ and 9-desmethyl-β-DHTBZ have half-lives of 7 hours, 5 hours and 12 hours respectively.

How it leaves the body

In a mass balance study in 6 healthy volunteers, approximately 75% of the dose was excreted in the urine, and fecal recovery accounted for approximately 7 to 16% of the dose.

With food

Food Effects The effects of food on the bioavailability of tetrabenazine were studied in subjects administered a single dose with and without food.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2025-10-13

Serious warning

The strongest warning the FDA requires. It is printed in a box at the top of the label.

DEPRESSION AND SUICIDALITY Tetrabenazine can increase the risk of depression and suicidal thoughts and behavior (suicidality) in patients with Huntington’s disease.
Anyone considering the use of tetrabenazine must balance the risks of depression and suicidality with the clinical need for control of chorea.
Close observation of patients for the emergence or worsening of depression, suicidality, or unusual changes in behavior should accompany therapy.
Patients, their caregivers, and families should be informed of the risk of depression and suicidality and should be instructed to report behaviors of concern promptly to the treating physician.
Particular caution should be exercised in treating patients with a history of depression or prior suicide attempts or ideation, which are increased in frequency in Huntington’s disease.
Tetrabenazine is contraindicated in patients who are actively suicidal, and in patients with untreated or inadequately treated depression [see Contraindications ( 4 ), Warnings and Precautions ( 5.1 )].
WARNING:
DEPRESSION AND SUICIDALITY See full prescribing information for complete boxed warning .
Increases the risk of depression and suicidal thoughts and behavior (suicidality) in patients with Huntington’s disease ( 5.1 ) Balance risks of depression and suicidality with the clinical need for control of chorea when considering the use of tetrabenazine tablets ( 5.2 ) Monitor patients for the emergence or worsening of depression, suicidality, or unusual changes in behavior ( 5.1 ) Inform patients, caregivers and families of the risk of depression and suicidality and instruct to report behaviors of concern promptly to the treating physician ( 5.1 ) Exercise caution when treating patients with a history of depression or prior suicide attempts or ideation ( 5.1 ) Tetrabenazine tablets are contraindicated in patients who are actively suicidal, and in patients with untreated or inadequately treated depression ( 4 , 5.1 )

Quoted from the official label, section “Boxed Warning”.

Do not take it if

Tetrabenazine tablets are contraindicated in patients:
Who are actively suicidal, or in patients with untreated or inadequately treated depression [see Warnings and Precautions ( 5.1 )] .
With hepatic impairment [see Use in Specific Populations ( 8.6 ), Clinical Pharmacology ( 12.3 )] .
Taking monoamine oxidase inhibitors (MAOIs).
Tetrabenazine tablets should not be used in combination with an MAOI, or within a minimum of 14 days of discontinuing therapy with an MAOI [see Drug Interactions ( 7.3 )] .
Taking reserpine.
At least 20 days should elapse after stopping reserpine before starting tetrabenazine tablets [see Drug Interactions ( 7.2 )] .
Taking deutetrabenazine or valbenazine [see Drug Interactions ( 7.7 )] .
Actively suicidal, or who have depression which is untreated or undertreated ( 4 , 5.1 ) Hepatic impairment ( 4 , 8.6 , 12.3 ) Taking monoamine oxidase inhibitors (MAOIs) or reserpine ( 4 , 7.2 , 7.3 ) Taking deutetrabenazine or valbenazine ( 4 , 7.7 )

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

Individualization of dose with careful weekly titration is required.
The 1 st week's starting dose is 12.5 mg daily; 2 nd week, 25 mg (12.5 mg twice daily); then slowly titrate at weekly intervals by 12.5 mg to a tolerated dose that reduces chorea.
( 2.1 , 2.2 ) Doses of 37.5 mg and up to 50 mg per day should be administered in three divided doses per day with a maximum recommended single dose not to exceed 25 mg.
( 2.2 ) Patients requiring doses above 50 mg per day should be genotyped for the drug metabolizing enzyme CYP2D6 to determine if the patient is a poor metabolizer (PM) or an extensive metabolizer (EM).
( 2.2 , 5.3 ) Maximum daily dose in PMs: 50 mg with a maximum single dose of 25 mg.
( 2.2 ) Maximum daily dose in EMs and intermediate metabolizers (IMs):
100 mg with a maximum single dose of 37.5 mg.
( 2.2 ) If serious adverse reactions occur, titration should be stopped and the dose should be reduced.
If the adverse reaction(s) do not resolve, consider withdrawal of tetrabenazine tablets.
( 2.2 )
2.1 General Dosing Considerations The chronic daily dose of tetrabenazine tablets used to treat chorea associated with Huntington's disease (HD) is determined individually for each patient.
When first prescribed, tetrabenazine therapy should be titrated slowly over several weeks to identify a dose of tetrabenazine tablets that reduces chorea and is tolerated.
Tetrabenazine tablets can be administered without regard to food [see Clinical Pharmacology ( 12.3 )] .
2.2 Individualization of Dose The dose of tetrabenazine tablets should be individualized.
Dosing Recommendations Up to 50 mg per day The starting dose should be 12.5 mg per day given once in the morning.
After one week, the dose should be increased to 25 mg per day given as 12.5 mg twice a day.
Tetrabenazine tablets should be titrated up slowly at weekly intervals by 12.5 mg daily, to allow the identification of a tolerated dose that reduces chorea.
If a dose of 37.5 mg to 50 mg per day is needed, it should be given in a three times a day regimen.
The maximum recommended single dose is 25 mg.
If adverse reactions such as akathisia, restlessness, parkinsonism, depression, insomnia, anxiety or sedation occur, titration should be stopped and the dose should be reduced.
If the adverse reaction does not resolve, consideration should be given to withdrawing tetrabenazine treatment or initiating other specific treatment (e.g., antidepressants) [see Adverse Reactions ( 6.1 )] .
Dosing Recommendations Above 50 mg per day Patients who require doses of tetrabenazine tablets greater than 50 mg per day should be first tested and genotyped to determine if they are poor metabolizers (PMs) or extensive metabolizers (EMs) by their ability to express the drug metabolizing enzyme, CYP2D6.
The dose of tetrabenazine should then be individualized accordingly to their status as PMs or EMs [see Warnings and Precautions ( 5.3 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )] .
Extensive and Intermediate CYP2D6 Metabolizers Genotyped patients who are identified as extensive (EMs) or intermediate metabolizers (IMs) of CYP2D6, who need doses of tetrabenazine tablets above 50 mg per day, should be titrated up slowly at weekly intervals by 12.5 mg daily, to allow the identification of a tolerated dose that reduces chorea.
Doses above 50 mg per day should be given in a three times a day regimen.
The maximum recommended daily dose is 100 mg and the maximum recommended single dose is 37.5 mg.
If adverse reactions such as akathisia, parkinsonism, depression, insomnia, anxiety or sedation occur, titration should be stopped and the dose should be reduced.
If the adverse reaction does not resolve, consideration should be given to withdrawing tetrabenazine treatment or initiating other specific treatment (e.g., antidepressants) [see Warnings and Precautions ( 5.3 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )] .
Poor CYP2D6 Metabolizers In PMs, the initial dose and titration is similar to EMs except that the recommended maximum single dose is 25 mg, and the recommended daily dose should not exceed a maximum of 50 mg [see Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )] . 2.3Dosage Adjustment withCYP2D6 Inhibitors Strong CYP2D6 Inhibitors Medications that are strong CYP2D6 inhibitors such as quinidine or antidepressants (e.g., fluoxetine, paroxetine) significantly increase the exposure to α-HTBZ and β-HTBZ; therefore, the total dose of tetrabenazine tablets should not exceed a maximum of 50 mg and the maximum single dose should not exceed 25 mg [see Warnings and Precautions ( 5.3 ), Drug Interactions ( 7.1 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )].
2.4 Discontinuation of Treatment Treatment with tetrabenazine can be discontinued without tapering.
Re-emergence of chorea may occur within 12 to 18 hours after the last dose of tetrabenazine [see Drug Abuse and Dependence ( 9.2 )] .
2.5 Resumption of Treatment Following treatment interruption of greater than five (5) days, tetrabenazine therapy should be re-titrated when resumed.
For short-term treatment interruption of less than five (5) days, treatment can be resumed at the previous maintenance dose without titration.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

Periodically reevaluate the benefit and potential for adverse effects such as worsening mood, cognition, rigidity, and functional capacity.
( 5.2 )
Do not exceed 50 mg/day and the maximum single dose should not exceed 25 mg if administered in conjunction with a strong CYP2D6 inhibitor (e.g., fluoxetine, paroxetine).
( 5.3 , 7.1 ) Neuroleptic Malignant Syndrome (NMS): Discontinue if this occurs.
( 5.4 , 7.6 ) Restlessness, agitation, akathisia and parkinsonism:
Reduce dose or discontinue if occurs.
( 5.5 , 5.6 ) Sedation/Somnolence:
May impair patient’s ability to drive or operate complex machinery.
( 5.7 ) QTc prolongation:
Not recommended in combination with other drugs that prolong QTc.
( 5.8 )
5.1 Depression and Suicidality Patients with Huntington’s disease are at increased risk for depression, suicidal ideation or behaviors (suicidality).
Tetrabenazine increases the risk for suicidality in patients with HD.
In a 12-week, double-blind, placebo-controlled study in patients with chorea associated with Huntington’s disease, 10 of 54 patients (19%) treated with tetrabenazine were reported to have an adverse event of depression or worsening depression compared to none of the 30 placebo-treated patients.
In two open-label studies (in one study, 29 patients received tetrabenazine for up to 48 weeks; in the second study, 75 patients received tetrabenazine for up to 80 weeks), the rate of depression/worsening depression was 35%.
In all of the HD chorea studies of tetrabenazine (n=187), one patient committed suicide, one attempted suicide, and six had suicidal ideation.
When considering the use of tetrabenazine, the risk of suicidality should be balanced against the need for treatment of chorea.
All patients treated with tetrabenazine should be observed for new or worsening depression or suicidality.
If depression or suicidality does not resolve, consider discontinuing treatment with tetrabenazine.
Patients, their caregivers, and families should be informed of the risks of depression, worsening depression, and suicidality associated with tetrabenazine, and should be instructed to report behaviors of concern promptly to the treating physician.
Patients with HD who express suicidal ideation should be evaluated immediately.
5.2 Clinical Worsening and Adverse Effects Huntington’s disease is a progressive disorder characterized by changes in mood, cognition, chorea, rigidity, and functional capacity over time.
In a 12-week controlled trial, tetrabenazine was also shown to cause slight worsening in mood, cognition, rigidity, and functional capacity.
Whether these effects persist, resolve, or worsen with continued treatment is unknown.
Prescribers should periodically re-evaluate the need for tetrabenazine in their patients by assessing the effect on chorea and possible adverse effects, including depression and suicidality, cognitive decline, parkinsonism, dysphagia, sedation/somnolence, akathisia, restlessness, and disability.
It may be difficult to distinguish between adverse reactions and progression of the underlying disease; decreasing the dose or stopping the drug may help the clinician distinguish between the two possibilities.
In some patients, underlying chorea itself may improve over time, decreasing the need for tetrabenazine.
5.3 Laboratory Tests Before prescribing a daily dose of tetrabenazine that is greater than 50 mg per day, patients should be genotyped to determine if they express the drug metabolizing enzyme, CYP2D6.
CYP2D6 testing is necessary to determine whether patients are poor metabolizers (PMs), extensive (EMs) or intermediate metabolizers (IMs) of tetrabenazine.
Patients who are PMs of tetrabenazine will have substantially higher levels of the primary drug metabolites (about 3-fold for α-HTBZ and 9-fold for β-HTBZ) than patients who are EMs.
The dosage should be adjusted according to a patient's CYP2D6 metabolizer status.
In patients who are identified as CYP2D6 PMs, the maximum recommended total daily dose is 50 mg and the maximum recommended single dose is 25 mg [see Dosage and Administration ( 2.2 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )] .
5.4 Neuroleptic Malignant Syndrome (NMS) A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with tetrabenazine and other drugs that reduce dopaminergic transmission [see Drug Interactions ( 7.6 )] .
Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status, and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmia).
Additional signs may include elevated creatinine phosphokinase, myoglobinuria, rhabdomyolysis, and acute renal failure.
The diagnosis of NMS can be complicated; other serious medical illness (e.g., pneumonia, systemic infection), and untreated or inadequately treated extrapyramidal disorders can present with similar signs and symptoms.
Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever, and primary central nervous system pathology.
The management of NMS should include (1) immediate discontinuation of tetrabenazine;
(2) intensive symptomatic treatment and medical monitoring; and (3) treatment of any concomitant serious medical problems for which specific treatments are available.
There is no general agreement about specific pharmacological treatment regimens for NMS.
Recurrence of NMS has been reported with resumption of drug therapy.
If treatment with tetrabenazine is needed after recovery from NMS, patients should be monitored for signs of recurrence.
5.5 Akathisia, Restlessness, and Agitation Tetrabenazine may increase the risk of akathisia, restlessness, and agitation.
In a 12-week, double-blind, placebo-controlled study in patients with chorea associated with HD, akathisia was observed in 10 (19%) of tetrabenazine-treated patients and 0% of placebo-treated patients.
In an 80-week open-label study, akathisia was observed in 20% of tetrabenazine-treated patients.
Patients receiving tetrabenazine should be monitored for the presence of akathisia.
Patients receiving tetrabenazine should also be monitored for signs and symptoms of restlessness and agitation, as these may be indicators of developing akathisia.
If a patient develops akathisia, the tetrabenazine dose should be reduced; however, some patients may require discontinuation of therapy.
5.6 Parkinsonism Tetrabenazine can cause parkinsonism.
In a 12-week, double-blind, placebo-controlled study in patients with chorea associated with HD, symptoms suggestive of parkinsonism (i.e., bradykinesia, hypertonia and rigidity) were observed in 15% of tetrabenazine-treated patients compared to 0% of placebo-treated patients.
In 48-week and 80-week, open-label studies, symptoms suggestive of parkinsonism were observed in 10% and 3% of tetrabenazine-treated patients, respectively.
Because rigidity can develop as part of the underlying disease process in Huntington's disease, it may be difficult to distinguish between this drug-induced adverse reaction and progression of the underlying disease process.
Drug-induced parkinsonism has the potential to cause more functional disability than untreated chorea for some patients with Huntington's disease.
If a patient develops parkinsonism during treatment with tetrabenazine, dose reduction should be considered; in some patients, discontinuation of therapy may be necessary.
5.7 Sedation and Somnolence Sedation is the most common dose-limiting adverse reaction of tetrabenazine.
In a 12-week, double-blind, placebo-controlled trial in patients with chorea associated with HD, sedation/somnolence occurred in 17/54 (31%) of tetrabenazine-treated patients and in 1 (3%) of placebo-treated patient.
Sedation was the reason upward titration of tetrabenazine was stopped and/or the dose of tetrabenazine was decreased in 15/54 (28%) patients.
In all but one case, decreasing the dose of tetrabenazine resulted in decreased sedation.
In 48-week and 80-week, open-label studies, sedation/somnolence occurred in 17% and 57% of tetrabenazine-treated patients, respectively.
In some patients, sedation occurred at doses that were lower than recommended doses.
Patients should not perform activities requiring mental alertness to maintain the safety of themselves or others, such as operating a motor vehicle or operating hazardous machinery, until they are on a maintenance dose of tetrabenazine and know how the drug affects them.
5.8 QTc Prolongation Tetrabenazine causes a small increase (about 8 msec) in the corrected QT (QTc) interval.
QT prolongation can lead to development of torsade de pointes-type ventricular tachycardia with the risk increasing as the degree of prolongation increases [see Clinical Pharmacology (12.2) ].
The use of tetrabenazine tablets should be avoided in combination with other drugs that are known to prolong QTc, including antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QTc interval [see Drug Interactions ( 7.5 ) ] .
Tetrabenazine should also be avoided in patients with congenital long QT syndrome and in patients with a history of cardiac arrhythmias.
Certain circumstances may increase the risk of the occurrence of torsade de pointes and/or sudden death in association with the use of drugs that prolong the QTc interval, including (1) bradycardia;
(3) concomitant use of other drugs that prolong the QTc interval; and (4) presence of congenital prolongation of the QT interval [see Clinical Pharmacology ( 12.2 )] .
5.9 Hypotension and Orthostatic Hypotension Tetrabenazine induced postural dizziness in healthy volunteers receiving single doses of 25 or 50 mg.
One subject had syncope, and one subject with postural dizziness had documented orthostasis.
Dizziness occurred in 4% of tetrabenazine-treated patients (vs. none on placebo) in the 12-week, controlled trial; however, blood pressure was not measured during these events.
Monitoring of vital signs on standing should be considered in patients who are vulnerable to hypotension.
5.10 Hyperprolactinemia Tetrabenazine elevates serum prolactin concentrations in humans.
Following administration of 25 mg to healthy volunteers, peak plasma prolactin levels increased 4- to 5-fold.
Tissue culture experiments indicate that approximately one third of human breast cancers are prolactin-dependent in vitro , a factor of potential importance if tetrabenazine is being considered for a patient with previously detected breast cancer.
Although amenorrhea, galactorrhea, gynecomastia, and impotence can be caused by elevated serum prolactin concentrations, the clinical significance of elevated serum prolactin concentrations for most patients is unknown.
Chronic increase in serum prolactin levels (although not evaluated in the tetrabenazine development program) has been associated with low levels of estrogen and increased risk of osteoporosis.
If there is a clinical suspicion of symptomatic hyperprolactinemia, appropriate laboratory testing should be done and consideration should be given to discontinuation of tetrabenazine.
5.11 Binding to Melanin-Containing Tissues Since tetrabenazine or its metabolites bind to melanin-containing tissues, it could accumulate in these tissues over time.
This raises the possibility that tetrabenazine may cause toxicity in these tissues after extended use.
Neither ophthalmologic nor microscopic examination of the eye has been conducted in the chronic toxicity studies in a pigmented species, such as dogs.
Ophthalmologic monitoring in humans was inadequate to exclude the possibility of injury occurring after long-term exposure.
The clinical relevance of tetrabenazine’s binding to melanin-containing tissues is unknown.
Although there are no specific recommendations for periodic ophthalmologic monitoring, prescribers should be aware of the possibility of long-term ophthalmologic effects [see Clinical Pharmacology ( 12.2 )] .

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

Risk Summary There are no adequate data on the developmental risk associated with the use of tetrabenazine in pregnant women.
Administration of tetrabenazine to rats throughout pregnancy and lactation resulted in an increase in stillbirths and postnatal offspring mortality.
Administration of a major human metabolite of tetrabenazine to rats during pregnancy or during pregnancy and lactation produced adverse effects on the developing fetus and offspring (increased mortality, decreased growth, and neurobehavioral and reproductive impairment).
The adverse developmental effects of tetrabenazine and a major human metabolite of tetrabenazine in rats occurred at clinically relevant doses [see Data] .
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
The background risk of major birth defects and miscarriage for the indicated population is unknown.
Data Animal Data Tetrabenazine had no clear effects on embryofetal development when administered to pregnant rats throughout the period of organogenesis at oral doses up to 30 mg/kg/day (or 3 times the maximum recommended human dose [MRHD] of 100 mg/day on a mg/m 2 basis).
Tetrabenazine had no effects on embryofetal development when administered to pregnant rabbits during the period of organogenesis at oral doses up to 60 mg/kg/day (or 12 times the MRHD on a mg/m 2 basis).
When tetrabenazine (5, 15, and 30 mg/kg/day) was orally administered to pregnant rats from the beginning of organogenesis through the lactation period, an increase in stillbirths and offspring postnatal mortality was observed at 15 and 30 mg/kg/day and delayed pup maturation was observed at all doses.
A no-effect dose for pre- and postnatal developmental toxicity in rats was not identified.
The lowest dose tested (5 mg/kg/day) was less than the MRHD on a mg/m 2 basis.
Because rats dosed orally with tetrabenazine do not produce 9-desmethyl-β-DHTBZ, a major human metabolite of tetrabenazine, the metabolite was directly administered to pregnant and lactating rats.
Oral administration of 9-desmethyl-β-DHTBZ (8, 15, and 40 mg/kg/day) throughout the period of organogenesis produced increases in embryofetal mortality at 15 and 40 mg/kg/day and reductions in fetal body weights at 40 mg/kg/day, which was also maternally toxic.
When 9-desmethyl-β-DHTBZ (8, 15, and 40 mg/kg/day) was orally administered to pregnant rats from the beginning of organogenesis through the lactation period, increases in gestation duration, stillbirths, and offspring postnatal mortality (40 mg/kg/day); decreases in pup weights (40 mg/kg/day); and neurobehavioral (increased activity, learning and memory deficits) and reproductive (decreased litter size) impairment (15 and 40 mg/kg/day) were observed.
Maternal toxicity was seen at the highest dose.
The no-effect dose for developmental toxicity in rats (8 mg/kg/day) was associated with plasma exposures (AUC) of 9-desmethyl-β-DHTBZ in pregnant rats lower than that in humans at the MRHD.
IN SPECIFIC POPULATIONS Pregnancy: Based on animal data, may cause fetal harm.
( 8.1 )
8.1 Pregnancy Risk Summary There are no adequate data on the developmental risk associated with the use of tetrabenazine in pregnant women.
Administration of tetrabenazine to rats throughout pregnancy and lactation resulted in an increase in stillbirths and postnatal offspring mortality.
Administration of a major human metabolite of tetrabenazine to rats during pregnancy or during pregnancy and lactation produced adverse effects on the developing fetus and offspring (increased mortality, decreased growth, and neurobehavioral and reproductive impairment).
The adverse developmental effects of tetrabenazine and a major human metabolite of tetrabenazine in rats occurred at clinically relevant doses [see Data] .
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
The background risk of major birth defects and miscarriage for the indicated population is unknown.
Data Animal Data Tetrabenazine had no clear effects on embryofetal development when administered to pregnant rats throughout the period of organogenesis at oral doses up to 30 mg/kg/day (or 3 times the maximum recommended human dose [MRHD] of 100 mg/day on a mg/m 2 basis).
Tetrabenazine had no effects on embryofetal development when administered to pregnant rabbits during the period of organogenesis at oral doses up to 60 mg/kg/day (or 12 times the MRHD on a mg/m 2 basis).
When tetrabenazine (5, 15, and 30 mg/kg/day) was orally administered to pregnant rats from the beginning of organogenesis through the lactation period, an increase in stillbirths and offspring postnatal mortality was observed at 15 and 30 mg/kg/day and delayed pup maturation was observed at all doses.
A no-effect dose for pre- and postnatal developmental toxicity in rats was not identified.
The lowest dose tested (5 mg/kg/day) was less than the MRHD on a mg/m 2 basis.
Because rats dosed orally with tetrabenazine do not produce 9-desmethyl-β-DHTBZ, a major human metabolite of tetrabenazine, the metabolite was directly administered to pregnant and lactating rats.
Oral administration of 9-desmethyl-β-DHTBZ (8, 15, and 40 mg/kg/day) throughout the period of organogenesis produced increases in embryofetal mortality at 15 and 40 mg/kg/day and reductions in fetal body weights at 40 mg/kg/day, which was also maternally toxic.
When 9-desmethyl-β-DHTBZ (8, 15, and 40 mg/kg/day) was orally administered to pregnant rats from the beginning of organogenesis through the lactation period, increases in gestation duration, stillbirths, and offspring postnatal mortality (40 mg/kg/day); decreases in pup weights (40 mg/kg/day); and neurobehavioral (increased activity, learning and memory deficits) and reproductive (decreased litter size) impairment (15 and 40 mg/kg/day) were observed.
Maternal toxicity was seen at the highest dose.
The no-effect dose for developmental toxicity in rats (8 mg/kg/day) was associated with plasma exposures (AUC) of 9-desmethyl-β-DHTBZ in pregnant rats lower than that in humans at the MRHD.
8.2 Lactation Risk Summary There are no data on the presence of tetrabenazine or its metabolites in human milk, the effects on the breastfed infant, or the effects of the drug on milk production.
The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for tetrabenazine and any potential adverse effects on the breastfed infant from tetrabenazine or from the underlying maternal condition.
8.4 Pediatric Use Safety and effectiveness in pediatric patients have not been established.
8.5 Geriatric Use The pharmacokinetics of tetrabenazine and its primary metabolites have not been formally studied in geriatric subjects.
8.6 HepaticImpairment Because the safety and efficacy of the increased exposure to tetrabenazine and other circulating metabolites are unknown, it is not possible to adjust the dosage of tetrabenazine in hepatic impairment to ensure safe use.
The use of tetrabenazine in patients with hepatic impairment is contraindicated [see Contraindications ( 4 ), Clinical Pharmacology ( 12.3 )] .
8.7 Poor or Extensive CYP2D6 Metabolizers Patients who require doses of tetrabenazine tablets greater than 50 mg per day, should be first tested and genotyped to determine if they are poor (PMs) or extensive metabolizers (EMs) by their ability to express the drug metabolizing enzyme, CYP2D6.
The dose of tetrabenazine should then be individualized accordingly to their status as either poor (PMs) or extensive metabolizers (EMs) [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.3 ), Clinical Pharmacology ( 12.3 )] .
Poor Metabolizers Poor CYP2D6 metabolizers (PMs) will have substantially higher levels of exposure to the primary metabolites (about 3-fold for α-HTBZ and 9-fold for β-HTBZ) compared to EMs.
The dosage should, therefore, be adjusted according to a patient’s CYP2D6 metabolizer status by limiting a single dose to a maximum of 25 mg and the recommended daily dose to not exceed a maximum of 50 mg/day in patients who are CYP2D6 PMs [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.3 ), Clinical Pharmacology ( 12.3 )] .
Extensive/Intermediate Metabolizers In extensive (EMs) or intermediate metabolizers (IMs), the dosage of tetrabenazine can be titrated to a maximum single dose of 37.5 mg and a recommended maximum daily dose of 100 mg [see Dosage and Administration ( 2.2 ), Drug Interactions ( 7.1 ), Clinical Pharmacology ( 12.3 )].

Quoted from the official label, section “OTC — Pregnancy or Breast Feeding”.

Other medicines

7.1 Strong CYP2D6 Inhibitors In vitro studies indicate that α-HTBZ and β-HTBZ are substrates for CYP2D6.
Strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine, quinidine) markedly increase exposure to these metabolites.
A reduction in tetrabenazine dose may be necessary when adding a strong CYP2D6 inhibitor (e.g., fluoxetine, paroxetine, quinidine) in patients maintained on a stable dose of tetrabenazine.
The daily dose of tetrabenazine should not exceed 50 mg per day and the maximum single dose of tetrabenazine should not exceed 25 mg in patients taking strong CYP2D6 inhibitors [see Dosage and Administration ( 2.3 ), Warnings and Precautions ( 5.3 ), Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )] .
7.2 Reserpine Reserpine binds irreversibly to VMAT2, and the duration of its effect is several days.
Prescribers should wait for chorea to re-emerge before administering tetrabenazine to
avoid overdosage and major depletion of serotonin and norepinephrine in the CNS.
At least 20 days should elapse after stopping reserpine before starting tetrabenazine.
Tetrabenazine and reserpine should not be used concomitantly [see Contraindications ( 4 )].
7.3 Monoamine Oxidase Inhibitors (MAOIs) Tetrabenazine is contraindicated in patients taking MAOIs.
Tetrabenazine should not be used in combination with an MAOI, or within a minimum of 14 days of discontinuing therapy with an MAOI [see Contraindications ( 4 )].
7.4 Alcohol or Other Sedating Drugs Concomitant use of alcohol or other sedating drugs may have additive effects and worsen sedation and somnolence [see Warnings and Precautions ( 5.7 )].
7.5 Drugs That Cause QTc Prolongation Tetrabenazine causes a small prolongation of QTc (about 8 msec), concomitant use with other drugs that are known to cause QTc prolongation should be avoided, these including antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications or any other medications known to prolong the QTc interval.
Tetrabenazine should be avoided in patients with congenital long QT syndrome and in patients with a history of cardiac arrhythmias.
Certain conditions may increase the risk for torsade de pointes or sudden death such as (1) bradycardia;
(2) hypokalemia or hypomagnesemia;
(3) concomitant use of other drugs that prolong the QTc interval; and (4) presence of congenital prolongation of the QT interval [see Warnings and Precautions ( 5.8 ), Clinical Pharmacology ( 12.2 )].
7.6 Neuroleptic Drugs The risk for Parkinsonism, NMS, and akathisia may be increased by concomitant use of tetrabenazine and dopamine antagonists or antipsychotics (e.g., chlorpromazine, haloperidol, olanzapine, risperidone, thioridazine, ziprasidone) [see Warnings and Precautions ( 5.4 , 5.5 , 5.6 )] .
7.7 Concomitant Deutetrabenazine or Valbenazine Tetrabenazine is contraindicated in patients currently taking deutetrabenazine or valbenazine.

Quoted from the official label, section “Drug Interactions”.

If you take too much

In an emergency, call your local emergency number or a poison control centre.

Three episodes of overdose occurred in the open-label trials performed in support of registration.
Eight cases of overdose with tetrabenazine have been reported in the literature.
The dose of tetrabenazine in these patients ranged from 100 mg to 1 g.
Adverse reactions associated with tetrabenazine overdose include acute dystonia, oculogyric crisis, nausea and vomiting, sweating, sedation, hypotension, confusion, diarrhea, hallucinations, rubor, and tremor.
Treatment should consist of those general measures employed in the management of overdosage with any CNS-active drug.
General supportive and symptomatic measures are recommended.
Cardiac rhythm and vital signs should be monitored.
In managing overdosage, the possibility of multiple drug involvement should always be considered.
The physician should consider contacting a poison control center on the treatment of any overdose.

Quoted from the official label, section “Overdosage”.

Misuse and dependence

9.1 Controlled Substance Tetrabenazine is not a controlled substance.
9.2 Abuse Clinical trials did not reveal patients developed drug seeking behaviors, though these observations were not systematic.
Abuse has not been reported from the postmarketing experience in countries where tetrabenazine has been marketed.
As with any CNS-active drug, prescribers should carefully evaluate patients for a history of drug abuse and follow such patients closely, observing them for signs of tetrabenazine misuse or abuse (such as development of tolerance, increasing dose requirements, drug-seeking behavior).
Abrupt discontinuation of tetrabenazine from patients did not produce symptoms of withdrawal or a discontinuation syndrome; only symptoms of the original disease were observed to re-emerge [see Dosage and Administration ( 2.4 )].
Tetrabenazine is not a controlled substance.

Quoted from the official label, section “Drug Abuse and Dependence”.

Use in children

Safety and effectiveness in pediatric patients have not been established.

Quoted from the official label, section “Pediatric Use”.

Use in older people

The pharmacokinetics of tetrabenazine and its primary metabolites have not been formally studied in geriatric subjects.

Quoted from the official label, section “Geriatric Use”.

Side effects

The following serious adverse reactions are described below and elsewhere in the labeling:
Depression and Suicidality [see Warnings and Precautions ( 5.1 )] Neuroleptic Malignant Syndrome (NMS) [see Warnings and Precautions ( 5.4 )] Akathisia, Restlessness, and Agitation [see Warnings and Precautions ( 5.5 )] Parkinsonism [see Warnings and Precautions ( 5.6 )] Sedation and Somnolence [see Warnings and Precautions ( 5.7 )] QTc Prolongation [see Warnings and Precautions ( 5.8 )] Hypotension and Orthostatic Hypotension [see Warnings and Precautions ( 5.9 )] Hyperprolactinemia [see Warnings and Precautions ( 5.10 )] Binding to Melanin-Containing Tissues [see Warnings and Precautions ( 5.11 )] Most common adverse reactions (>10% and at least 5% greater than placebo) were:
Sedation/somnolence, fatigue, insomnia, depression, akathisia, anxiety/anxiety aggravated, nausea.
( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Apotex Corp. at 1-800-706-5575 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
During its development, tetrabenazine was administered to 773 unique subjects and patients.
The conditions and duration of exposure to tetrabenazine varied greatly, and included single-dose and multiple-dose clinical pharmacology studies in healthy volunteers (n=259) and open-label (n=529) and double-blind studies (n=84) in patients.
In a randomized, 12-week, placebo-controlled clinical trial of HD patients, adverse reactions were more common in the tetrabenazine group than in the placebo group.
Forty-nine of 54 (91%) patients who received tetrabenazine experienced one or more adverse reactions at any time during the study.
The most common adverse reactions (over 10%, and at least 5% greater than placebo) were sedation/somnolence, fatigue, insomnia, depression, akathisia, anxiety/anxiety aggravated, and nausea.
Adverse Reactions Occurring in ≥4% of Patients The number and percentage of the most common adverse reactions that occurred at any time during the study in ≥4% of tetrabenazine-treated patients, and with a greater frequency than in placebo-treated patients, are presented in Table 1.
Table 1 :
Adverse Reactions in a 12-Week, Double-Blind, Placebo-Controlled Trial in Patients with Huntington’s Disease Adverse Reaction Tetrabenazine n = 54 (%) Placebo n = 30 (%) Sedation/somnolence 31 3 Insomnia 22 0 Fatigue 22 13 Depression 19 0 Akathisia 19 0 Anxiety/anxiety aggravated 15 3 Fall 15 13 Nausea 13 7 Upper respiratory tract infection 11 7 Irritability 9 3 Balance difficulty 9 0 Parkinsonism/bradykinesia 9 0 Vomiting 6 3 Laceration (head) 6 0 Ecchymosis 6 0 Decreased appetite 4 0 Obsessive reaction 4 0 Dizziness 4 0 Dysarthria 4 0 Unsteady gait 4 0 Headache 4 3 Shortness of breath 4 0 Bronchitis 4 0 Dysuria 4 0 Dose escalation was discontinued or dosage of study drug was reduced because of one or more adverse reactions in 28 of 54 (52%) patients randomized to tetrabenazine.
These adverse reactions consisted of sedation (15), akathisia (7), parkinsonism (4), depression (3), anxiety (2), fatigue (1) and diarrhea (1).
Some patients had more than one AR and are, therefore, counted more than once.
Adverse Reactions Due to Extrapyramidal Symptoms Table 2 describes the incidence of events considered to be extrapyramidal adverse reactions which occurred at a greater frequency in tetrabenazine-treated patients compared to placebo-treated patients.
Table 2:
Adverse Reactions Due to Extrapyramidal Symptoms in a 12-Week, Double-Blind, Placebo-Controlled Trial in Patients with Huntington’s Disease Tetrabenazine n = 54 % Placebo n = 30 % Akathisia 1 19 0 Extrapyramidal event 2 15 0 Any extrapyramidal event 33 0 1 Patients with the following adverse event preferred terms were counted in this category:
akathisia, hyperkinesia, restlessness. 2 Patients with the following adverse event preferred terms were counted in this category:
bradykinesia, parkinsonism, extrapyramidal disorder, hypertonia.
Patients may have had events in more than one category.
Dysphagia Dysphagia is a component of HD.
However, drugs that reduce dopaminergic transmission have been associated with esophageal dysmotility and dysphagia.
Dysphagia may be associated with aspiration pneumonia.
In a 12-week, double-blind, placebo-controlled study in patients with chorea associated with HD, dysphagia was observed in 4% of tetrabenazine-treated patients and 3% of placebo-treated patients.
In 48-week and 80-week, open-label studies, dysphagia was observed in 10% and 8% of tetrabenazine-treated patients, respectively.
Some of the cases of dysphagia were associated with aspiration pneumonia.
Whether these events were related to treatment is unknown.
6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of tetrabenazine tablets.
Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Nervous system disorders:
tremor Psychiatric disorders:
confusion, worsening aggression Respiratory, thoracic and mediastinal disorders:
pneumonia Skin and subcutaneous tissue disorders:
hyperhidrosis, skin rash

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

Advise the patient to read the FDA-approved patient labeling (Medication Guide).
Risk of Suicidality Inform patients and their families that tetrabenazine tablets may increase the risk of suicidal thinking and behaviors.
Counsel patients and their families to remain alert to the emergence of suicidal ideation and to report it immediately to the patient’s physician [see Contraindications ( 4 ), Warnings and Precautions ( 5.1 )] .
Risk of Depression Inform patients and their families that tetrabenazine tablets may cause depression or may worsen pre-existing depression.
Encourage patients and their families to be alert to the emergence of sadness, worsening of depression, withdrawal, insomnia, irritability, hostility (aggressiveness), akathisia (psychomotor restlessness), anxiety, agitation, or panic attacks and to report such symptoms promptly to the patient’s physician [see Contraindications ( 4 ), Warnings and Precautions ( 5.1 )] .
Dosing of Tetrabenazine Inform patients and their families that the dose of tetrabenazine tablets will be increased slowly to the dose that is best for each patient.
Sedation, akathisia, parkinsonism, depression, and difficulty swallowing may occur.
Such symptoms should be promptly reported to the physician, and the tetrabenazine tablets dose may need to be reduced or discontinued [see Dosage and Administration ( 2.2 )] .
Risk of Sedation and Somnolence Inform patients that tetrabenazine tablets may induce sedation and somnolence and may impair the ability to perform tasks that require complex motor and mental skills.
Advise patients that until they learn how they respond to tetrabenazine tablets, they should be careful doing activities that require them to be alert, such as driving a car or operating machinery [see Warnings and Precautions ( 5.7 )] .
Interaction with Alcohol Advise patients and their families that alcohol may potentiate the sedation induced by tetrabenazine tablets [see Drug Interactions ( 7.4 )].
Usage in Pregnancy Advise patients and their families to notify the physician if the patient becomes pregnant or intends to become pregnant during tetrabenazine therapy, or is breastfeeding or intending to breastfeed an infant during therapy [see Use in Specific Populations ( 8.1 )] .
All registered trademarks in this document are the property of their respective owners.
Dispense with Medication Guide available at www1.apotex.com/products/us APOTEX INC.
Tetrabenazine Tablets 12.5 mg and 25 mg Manufactured by Apotex Inc.
Toronto, Ontario Canada M9L 1T9 Manufactured for Apotex Corp.
Weston, Florida USA 33326 Revised: November 2021 Revision: 5 Marketed by: GSMS, Inc.
Camarillo, CA 93012 USA

Quoted from the official label, section “Patient Counseling Information”.

Strengths and forms

FORMS AND STRENGTHS Tetrabenazine tablets are available in the following strengths:
Tetrabenazine tablets 12.5 mg are available for oral administration as white to off-white, round, flat face, bevelled edge, unscored tablets, engraved “T12.5” on one side, “APO” on the other side.
Tetrabenazine tablets 25 mg are available for oral administration as yellow, round, flat face, bevelled edge tablets with functional scoring on one side, engraved “APO” over “T25” on the other side.
Tablets: 12.5 mg non-scored and 25 mg with functional score ( 3 )

Quoted from the official label, section “Dosage Forms & Strengths”.

What it looks like and how it is packed

16.1 How Supplied Tetrabenazine tablets are available in the following strengths and packages:
Tetrabenazine tablets 12.5 mg are available for oral administration as white to off-white, round, flat face, bevelled edge, unscored tablets, engraved "T12.5" on one side, "APO" on the other side.
They are supplied as follows:
Bottles of 112 NDC 51407-480-12 Tetrabenazine tablets 25 mg are available for oral administration as yellow, round, flat face, bevelled edge tablets with functional scoring on one side, engraved "APO" over "T25" on the other side.
They are supplied as follows: Bottles of 112 NDC 51407-481-12
Storage
Store at 20ºC to 25ºC (68ºF to 77ºF); excursions permitted from 15ºC to 30ºC (59ºF to 86ºF) [see USP Controlled Room Temperature].

Quoted from the official label, section “How Supplied”.

How to store it

Store at 20ºC to 25ºC (68ºF to 77ºF); excursions permitted from 15ºC to 30ºC (59ºF to 86ºF) [see USP Controlled Room Temperature].

Quoted from the official label, section “Storage and Handling”.

What is in it

Tetrabenazine is a monoamine depletor for oral administration.
The molecular weight of tetrabenazine is 317.43 g/mol; the pKa is 6.51.
Tetrabenazine is a hexahydro-dimethoxy-benzoquinolizine derivative and has the following chemical name:
cis rac –1,3,4,6,7,11b-hexahydro-9,10-dimethoxy-3-(2-methylpropyl)-2H-benzo[a]quinolizin-2-one.
The molecular formula C 19 H 27 NO 3 is represented by the following molecular structure:
Tetrabenazine is a white to almost white powder that is sparingly soluble in water and soluble in ethanol.
Each tetrabenazine tablet contains either 12.5 or 25 mg of tetrabenazine as the active ingredient.
Tetrabenazine tablets contain tetrabenazine as the active ingredient and the following inactive ingredients:
anhydrous lactose, colloidal silicon dioxide, croscarmellose sodium and magnesium stearate.
The 25 mg strength tablet also contains ferric oxide yellow as an inactive ingredient.
Tetrabenazine tablets are supplied as a yellow tablet with functional score containing 25 mg of tetrabenazine or as an unscored white to off-white tablet containing 12.5 mg of tetrabenazine.
Structure.jpg

Quoted from the official label, section “Description”.

Ingredients people check for

Lactose, gluten, dyes, sugars and other ingredients that matter with an allergy, intolerance or diet — as this product’s FDA label lists them.

Lactoseanhydrous lactoseMilk sugar: matters with lactose intolerance or a milk allergy.

Quoted from the FDA label. A label that does not name an ingredient is not a guarantee that the product is free of it, and formulations change. With an allergy, check the pack and ask a pharmacist.

Every version of this medicine (12)

The same active substance, strength and kind of form, from every company that sells it — with what each label lists.

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Same active substance, strength and form in other countries

Matched on active substance, strength and kind of form only. This is not a statement that the products are equivalent or interchangeable: other ingredients, release and approved uses can differ — ask a pharmacist before swapping.

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Details

Made by	Golden State Medical Supply, Inc.
Active substance	Tetrabenazine
Strength	25 mg
Form	Tablet
Route	Oral
Packs	112 TABLET in 1 BOTTLE
NDC	51407-481

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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Other strengths and forms

22 products are sold under this name. Grouped by form; a number on a strength means several companies make it.

Tablet20 products
- 12.5 mg10
  12.5 mg · 10 companies
  +2 more
- 25 mg10
  25 mg · 10 companies
  - Ajanta Pharma USA Inc.
  - Apotex Corp.
  - Bionpharma Inc.
  - Dr. Reddys Laboratories Inc
  - Golden State Medical Supply, Inc. · this page
  - Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.
  - Oceanside Pharmaceuticals
  - Precision Dose Inc.
  +2 more
Tablet, Coated2 products
- 12.5 mg
- 25 mg

Same active substance

These contain the same substance. That does not mean one can replace another — ask a pharmacist.

Tetrabenazine12.5 mgPrescription onlyTablet Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. · Tetrabenazine Tetrabenazine25 mgPrescription onlyTablet Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. · Tetrabenazine Tetrabenazine12.5 mgPrescription onlyTablet Ajanta Pharma USA Inc. · Tetrabenazine Tetrabenazine25 mgPrescription onlyTablet Ajanta Pharma USA Inc. · Tetrabenazine Tetrabenazine12.5 mgPrescription onlyTablet, Coated Camber Pharmaceuticals, Inc. · Tetrabenazine Tetrabenazine25 mgPrescription onlyTablet, Coated Camber Pharmaceuticals, Inc. · Tetrabenazine

See every product with Tetrabenazine