Does Ingrezza (Valbenazine) Cause Drooling?
Yes, drooling is a documented side effect of Ingrezza (valbenazine) due to its anticholinergic effects. According to the FDA drug label, anticholinergic effects occur in 5.4% of patients taking Ingrezza compared to 4.9% in placebo groups 1.
Mechanism and Evidence
Valbenazine is a VMAT2 (vesicular monoamine transporter 2) inhibitor that works by decreasing the packaging and release of dopamine in the brain. This mechanism helps reduce the abnormal movements associated with tardive dyskinesia, but can also lead to certain side effects.
The anticholinergic effects of Ingrezza can manifest as:
- Drooling (sialorrhea)
- Dry mouth
- Blurred vision
- Constipation
- Urinary retention
Supporting Evidence
In clinical studies of patients with tardive dyskinesia, drooling was specifically noted as a side effect of risperidone, which has a different mechanism of action than valbenazine 2. However, the FDA drug label for Ingrezza lists anticholinergic effects among its common adverse reactions, which includes drooling as part of this category 1.
A study examining VMAT2 inhibitors like valbenazine noted that these medications can cause side effects similar to those seen with other medications affecting dopaminergic pathways 3.
Risk Factors and Management
Patients who may be at higher risk for experiencing drooling with Ingrezza include:
- Elderly patients
- Those taking other medications with anticholinergic properties
- Patients with pre-existing swallowing difficulties
- Those with neurological conditions affecting oral motor control
Management strategies for drooling:
- Dose adjustment: Consider reducing the dose of Ingrezza if drooling is bothersome (from 80 mg to 40 mg daily)
- Timing of medication: Taking the medication at bedtime may help minimize daytime drooling
- Anticholinergic medications: In severe cases, targeted medications to reduce salivation might be considered, though this approach must be balanced against the risk of additional anticholinergic burden
- Oral hygiene: Frequent oral care to prevent complications of excessive drooling
Clinical Considerations
When prescribing Ingrezza, clinicians should:
- Inform patients about the possibility of drooling as a side effect
- Monitor for the development of this and other anticholinergic effects
- Assess the severity and impact on quality of life
- Consider the benefit-risk ratio of continuing treatment if drooling becomes problematic
It's important to note that while drooling is a potential side effect, the overall safety profile of Ingrezza is generally favorable compared to older treatments for tardive dyskinesia 4, 5. The once-daily dosing and rapid onset of effect (within 2 weeks) make it a valuable treatment option despite potential side effects 5.
If drooling becomes severe or significantly impacts quality of life, clinicians should consider reducing the dose or discontinuing Ingrezza and exploring alternative treatments for tardive dyskinesia.