Description

Tetrabenazine Tablets 12.5mg & 25mg – Uses, Dosage, Side Effects & Precautions

Tetrabenazine tablets are prescription medications used to treat involuntary movements (chorea) caused by Huntington’s disease. By blocking the VMAT2 protein, tetrabenazine lowers levels of certain brain chemicals (dopamine, serotonin, norepinephrine), helping control uncontrollable body movements. Unlike some antipsychotics, tetrabenazine has the potential advantage of not causing tardive dyskinesia.

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Key Features of Tetrabenazine

• Active Ingredient: Tetrabenazine

• Strengths Available: 12.5 mg & 25 mg tablets

• Indication: Management of chorea (involuntary movements) in Huntington’s disease

• Mechanism of Action:

  • Selective inhibition of VMAT2 transporter → reduces monoamine neurotransmitters (dopamine, serotonin, norepinephrine).

  • Weak blockade of dopamine D2 receptors → decreases hyperkinetic (excessive) movements.

• Advantage: Lower risk of tardive dyskinesia compared to typical antipsychotics.

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Dosage & Administration

• Adults (Huntington’s Chorea):

  • Initial dose: 12.5 mg once daily (morning).

  • After 1 week: Increase to 12.5 mg twice daily.

  • Maintenance: Titrate gradually by 12.5 mg weekly to lowest effective dose.

  • Maximum single dose: 25 mg

  • Maximum daily dose: 200 mg (in divided doses).

• CYP2D6 Genotyping (for doses >50 mg/day):

  • Poor metabolizers (PM): Max 50 mg/day.

  • Extensive metabolizers (EM): Max 100 mg/day.

• Elderly: Use with caution; may cause Parkinson-like symptoms.

• Children: Not recommended (no adequate studies).

• Hepatic impairment: Start at half dose with slow titration.

• Renal impairment: Use cautiously (limited data).

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Common Side Effects

• Drowsiness or fatigue

• Depression or mood changes

• Parkinson-like symptoms (rigidity, slowed movement)

• Nausea, vomiting, diarrhea

• Insomnia or restlessness

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Serious Side Effects (Seek Medical Help Immediately)

• Severe depression or suicidal thoughts

• Worsening involuntary movements

• Severe liver problems

• Extreme drowsiness or confusion

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Important Safety Information

• May increase risk of depression and suicidal thoughts – regular monitoring is essential.

• If treatment is stopped for more than 5 days, re-titration is required.

• Store at 25°C (77°F), protected from light.

• Take regularly to achieve best results.

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Inactive Ingredients

• Lactose monohydrate

• Maize/Corn starch

• Talc

• Magnesium stearate

• Sodium starch glycolate

• Colloidal anhydrous silica

• Iron oxide yellow

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Product Information

• Brand Names: Xenazine, Nitoman, Xentra (varies by region)

• Generic Name: Tetrabenazine

• Therapeutic Class: VMAT2 Inhibitor, Movement Disorder Treatment

• Pack Sizes: Varies (commonly 25 or 100 tablets per pack)