New Study Finds Ambroxol May Alleviate Parkinson’s-Related Dementia

A recent clinical trial has revealed promising results regarding the use of Ambroxol, a cough medicine commonly used in Europe, as a potential treatment for dementia associated with Parkinson's disease. The 12-month study, led by Dr. Stephen Pasternak, a professor at Schulich Medicine & Dentistry and a researcher at the Lawson Research Institute, involved 55 participants diagnosed with Parkinson’s disease dementia.

The findings, published in the esteemed *JAMA Neurology* journal on June 30, 2025, indicate that Ambroxol not only proved safe and well-tolerated among participants, but also reached therapeutic levels in the brain. Notably, while psychiatric symptoms worsened in the placebo group, those taking Ambroxol exhibited stable psychiatric conditions. Furthermore, participants possessing high-risk GBA1 gene variants demonstrated improved cognitive performance when administered Ambroxol.

Parkinson's disease dementia is a significant concern, affecting approximately half of those diagnosed with Parkinson’s within a decade. Symptoms include memory deterioration, confusion, hallucinations, and mood fluctuations, significantly impacting patients and their families. The urgency for effective treatments is underscored by current therapies that primarily address symptoms without halting the underlying disease progression.

Dr. Pasternak explained, "Current therapies for Parkinson’s disease and dementia address symptoms but do not stop the underlying disease. 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."

Ambroxol functions by enhancing the activity of a crucial enzyme known as glucocerebrosidase (GCase), encoded by the GBA1 gene. In individuals with Parkinson’s disease, GCase levels are typically low, leading to waste accumulation in brain cells and subsequent damage. Dr. Pasternak’s interest in Ambroxol originated during a fellowship at The Hospital for Sick Children in Toronto, where it was identified as a treatment for Gaucher disease, a rare genetic disorder.

The study, funded by the Weston Family Foundation, marks a significant advance in the quest for new treatments for Parkinson’s disease and related cognitive disorders, including dementia with Lewy bodies. Dr. Pasternak and his team are planning to initiate a follow-up clinical trial focusing specifically on cognitive outcomes later this year.

The implications of this research are profound. If further studies validate these findings, Ambroxol could offer new hope for patients suffering from Parkinson's-related dementia, improving not only cognitive function but also overall quality of life for those affected by this debilitating condition.