Indications
Ajuben is a vesicular monoamine transporter 2 (VMAT2) inhibitor indicated for the treatment of:

• Chorea associated with Huntington's disease
• Tardive dyskinesia in adults
  Use as prescribed by a registered healthcare professional.

Pharmacology
The exact mechanism by which deutetrabenazine alleviates chorea symptoms remains unclear. However, it is believed to work by depleting monoamines (such as dopamine, serotonin, norepinephrine, and histamine) from nerve terminals. The primary metabolites of deutetrabenazine (α-dihydrotetrabenazine and β-dihydrotetrabenazine) act as reversible inhibitors of vesicular monoamine transporter 2 (VMAT2), reducing the uptake of monoamines into synaptic vesicles and leading to a depletion of these neurotransmitters in the brain.

Dosage & Administration
For Patients Not Currently on Tetrabenazine:

• For Chorea associated with Huntington’s disease:
  • Initial dose: 6 mg per day
  • Maintenance dose: 6 mg to 48 mg per day
  • Maximum dose: 48 mg per day
• For Tardive dyskinesia:
  • Initial dose: 12 mg per day
  • Maintenance dose: 12 mg to 48 mg per day
  • Maximum dose: 48 mg per day

Start with an initial dose, and gradually increase by 6 mg weekly to the highest tolerated dose. The total daily dose should be divided into two doses if the total is 12 mg or more, and it should be taken with food.

For Patients Switching from Tetrabenazine to Deutetrabenazine:
Discontinue tetrabenazine and begin with deutetrabenazine the following day. The starting dose for patients transitioning from tetrabenazine is as follows:

After transitioning to deutetrabenazine, the dose can be adjusted weekly based on the patient’s response.

Always follow the dosage as recommended by your healthcare provider.

Interactions

• When used with strong CYP2D6 inhibitors, the maximum recommended dose of Ajuben is 36 mg per day (18 mg twice daily).
• Alcohol or other sedative drugs may increase the sedative effects and cause excessive sleepiness.

Contraindications
Deutetrabenazine should not be used in patients with:

• Suicidal thoughts or untreated/inadequately treated depression
• Hepatic impairment
• Those taking MAOIs, reserpine, or tetrabenazine

Side Effects
The most common side effects of deutetrabenazine (affecting more than 8% of patients) include:

• Somnolence (sleepiness)
• Diarrhea
• Dry mouth
• Fatigue

Pregnancy & Lactation
There are insufficient data to determine the risk associated with using deutetrabenazine during pregnancy. The effects on human milk or breastfed infants are not well understood. Caution is advised when administering this medication to breastfeeding mothers.

Precautions & Warnings

• Patients may experience Neuroleptic Malignant Syndrome. If this occurs, discontinue Ajuben immediately.
• Akathisia, agitation, restlessness, and Parkinsonism may occur. In such cases, reduce the daily dose or discontinue the medication.
• Sedation or excessive sleepiness may occur; patients should be monitored.

Use in Special Populations

• Use in Children: The safety and effectiveness of deutetrabenazine in children and infants have not been established.
• Patients with Hepatic or Renal Impairment: There are no studies evaluating the effects of hepatic or renal impairment on Ajuben's pharmacokinetics.
• For Poor CYP2D6 Metabolizers: The maximum recommended dose for these patients is 36 mg per day (18 mg twice daily).

Overdose Effects
Overdose may result in the following symptoms:

• Acute dystonia, oculogyric crisis, nausea, vomiting, sweating, sedation, hypotension, confusion, diarrhea, hallucinations, rubor (redness of the skin), and tremors.

Storage Conditions
Store below 30°C, away from light and moisture. Keep out of reach of children.