Ingrezza (Valbenazine) Dosing for Tremors
Ingrezza (valbenazine) is not FDA-approved for the treatment of tremors. The FDA-approved indications for Ingrezza are tardive dyskinesia and chorea associated with Huntington's disease 1.
Dosing for FDA-Approved Indications
For reference, the FDA-approved dosing for Ingrezza is:
Tardive Dyskinesia:
- Initial dose: 40 mg once daily
- After 1 week: Increase to 80 mg once daily
- Alternative maintenance dose: 60 mg once daily may be considered based on response and tolerability
Chorea Associated with Huntington's Disease:
- Initial dose: 40 mg once daily
- Titration: Can be increased every 2 weeks in 20 mg increments
- Maximum dose: 80 mg once daily
Important Clinical Considerations
Valbenazine works through reversible inhibition of vesicular monoamine transporter 2 (VMAT2), which regulates monoamine uptake from the cytoplasm to the synaptic vesicle 1.
The medication reaches steady-state plasma concentrations within 1 week of starting treatment 1.
Valbenazine has a half-life of 15-22 hours, making once-daily dosing appropriate 1.
For patients with moderate or severe hepatic impairment, dose adjustments are necessary due to increased drug exposure 1.
When used with strong CYP3A4 inhibitors or strong CYP2D6 inhibitors, dose adjustments may be required 1.
Off-Label Use for Tremors
While Ingrezza has shown efficacy in treating movement disorders like tardive dyskinesia and chorea, there is insufficient evidence supporting its use specifically for tremors.
For tremor management, other medications have established efficacy:
Essential tremor: First-line treatments include propranolol (80-240 mg/day) or primidone (50-1000 mg/day) 2, 3.
Cerebellar tremors: Carbamazepine (400-600 mg/day) has shown benefit 4.
Clinical Recommendation
If considering Ingrezza for tremors (off-label use), the dosing protocol would reasonably follow the FDA-approved regimen for movement disorders: start at 40 mg once daily and titrate to 80 mg once daily after one week, with dose adjustments based on hepatic function and drug interactions.
Monitoring and Safety
Monitor for QT prolongation, particularly in CYP2D6 poor metabolizers or patients taking strong CYP2D6 or CYP3A4 inhibitors 1.
Common side effects include somnolence and QT prolongation 1.
Valbenazine should be used with caution in patients with congenital long QT syndrome or cardiac arrhythmias 1.
The medication can be taken with or without food, though high-fat meals may decrease peak concentration 1.
Remember that using Ingrezza for tremors represents off-label use, and treatment decisions should be based on careful assessment of potential benefits versus risks, especially given the lack of specific evidence for this indication.