Recent research suggests that Ambroxol, a widely available cough syrup in Europe, may offer new hope for people living with Parkinson’s disease-related dementia. A randomized clinical trial published in JAMA Neurology shows that Ambroxol is safe and well-tolerated and may protect cognitive function in patients with Parkinson’s disease.
What Is Ambroxol?
Ambroxol is an over-the-counter mucolytic cough syrup sold in Europe. It works by loosening mucus in the lungs, making it easier to cough out. But scientists have now found it may do more than treat cough. Ambroxol appears to increase levels of an important enzyme called beta-glucocerebrosidase (GCase)—often found at low levels in people with Parkinson’s disease.
Why GCase Matters in Parkinson’s Disease
GCase is responsible for breaking down waste inside cells. When GCase levels are low, harmful waste can build up inside brain cells, potentially leading to neurodegeneration and cognitive decline.
This study explored whether boosting GCase activity with Ambroxol could reduce symptoms of Parkinson’s disease dementia—a condition that currently has limited treatment options.
Inside the Ambroxol Clinical Trial
The trial, conducted by researchers including Dr. Stephen Pasternak from the Lawson Research Institute and Western University, included 55 patients with mild to moderate Parkinson’s dementia. Participants were randomly assigned to take Ambroxol or a placebo once daily for 52 weeks.
Key findings:
- Ambroxol was safe and well-tolerated, with only mild to moderate gastrointestinal issues.
- ADAS-Cog scores (a measure of cognitive function) didn’t show a significant difference overall.
- However, neuropsychiatric symptoms worsened in the placebo group but remained stable in the Ambroxol group.
- In patients with a GBA1 gene variant—which increases the risk of dementia in Parkinson’s disease—those taking Ambroxol showed cognitive improvement.
- A brain damage marker (GFAP) increased in the placebo group but remained stable with Ambroxol, suggesting potential neuroprotection.
What Is the GBA1 Gene?
The GBA1 gene produces the GCase enzyme. People with Parkinson’s disease who have GBA1 mutations are more likely to experience earlier onset and faster cognitive decline. This study found that Ambroxol may be especially helpful for patients with these gene variants.
Hope for the Future: More Trials Underway
While this study is early-stage, it lays the groundwork for larger and more definitive trials. Currently, three additional clinical trials are investigating Ambroxol for Parkinson’s:
- ASPro-PD – Ambroxol to Slow Progression in Parkinson Disease
- ANeED – Ambroxol in Early Dementia with Lewy Bodies
- AMBITIOUS – Focused on GBA1 gene variant carriers
These trials aim to confirm Ambroxol’s safety and effectiveness in larger patient groups.
Why This Matters
There is no cure for Parkinson’s disease, and current dementia treatments only manage symptoms. Ambroxol offers a potential disease-modifying therapy that targets the root cause—especially for genetically at-risk individuals.
“These findings suggest Ambroxol may protect brain function, especially in those genetically at risk. It offers a promising new treatment avenue where few currently exist,” said Dr. Pasternak.
Final Thoughts
Although Ambroxol is not approved for use in Canada, the U.S., or the U.K., this research offers hope for patients and families dealing with the cognitive challenges of Parkinson’s disease dementia. As science progresses, it’s possible that a simple cough syrup could play a powerful role in future treatment strategies.
This article is for informational purposes only and does not constitute medical advice. Ambroxol is not currently approved for the treatment of Parkinson’s disease in Canada, the U.S., or the U.K. Always consult your healthcare provider before making any changes to your treatment plan.