Can Austedo XR Cause Excessive Salivation?
No, Austedo XR (deutetrabenazine) does not typically cause excessive salivation; in fact, it is not listed as a known adverse effect in the FDA prescribing information. However, the combination of dextromethorphan/quinidine (a different medication sometimes confused with Austedo XR) has been associated with increased salivation in specific contexts.
Key Distinction: Austedo XR vs. Dextromethorphan/Quinidine
It's critical to clarify that Austedo XR contains deutetrabenazine, not dextromethorphan/quinidine 1. These are entirely different medications:
- Austedo XR (deutetrabenazine): A VMAT2 inhibitor used for chorea in Huntington's disease and tardive dyskinesia 1
- Dextromethorphan/quinidine (Nuedexta): Used for pseudobulbar affect and has been studied for bulbar symptoms in ALS 2, 3, 4
Adverse Effects of Austedo XR
The FDA-approved prescribing information for Austedo XR does not list excessive salivation (hypersalivation or sialorrhea) as a recognized adverse effect 1. The documented side effects include:
- Depression and suicidality (particularly in Huntington's disease patients) 1
- QTc interval prolongation 1
- Parkinsonism 1
- Sedation and somnolence 1
- Akathisia and restlessness 1
Context: Medications That Do Cause Excessive Salivation
If you're concerned about drug-induced sialorrhea, the following medication classes are well-established culprits:
- Clozapine and other antipsychotics: Clozapine notably causes hypersalivation in a significant proportion of patients 5, 6
- Cholinergic agonists: Direct and indirect cholinergic agents used for Alzheimer's disease and myasthenia gravis 6, 7
- Certain psychoactive medications: Including some antidepressants and antipsychotics 7
The American Geriatrics Society Beers Criteria mentions that dextromethorphan/quinidine should be used with caution in older adults due to limited efficacy in behavioral symptoms of dementia and potential for falls and drug interactions, but does not specifically highlight excessive salivation as a concern 5.
Clinical Implications
If a patient on Austedo XR develops excessive salivation, consider alternative causes including:
Austedo XR's mechanism as a VMAT2 inhibitor depletes monoamines from nerve terminals 1, which does not typically result in increased salivation
Monitor for the documented adverse effects of Austedo XR, particularly depression, QTc prolongation, and parkinsonism, rather than salivation changes 1