The clinical trial will examine whether ambroxol can slow dementia in people with Parkinson's disease

The clinical trial will examine whether ambroxol can slow dementia in people with Parkinson's disease

Dementia represents a major health challenge without safe, affordable treatments to slow its progression.

Researchers at the Lawson Research Institute (Lawson), the research arm of St. Joseph's Health Care London, are studying whether ambroxol - a safe cough medicine used in Europe for decades - can slow Parkinson's disease in people with Parkinson's disease.

Published today in the prestigious publicationJAMA -NeurologyThis 12-month clinical trial of 55 participants with Parkinson's disease dementia (PDD) monitored memory, psychiatric symptoms and GFAP, a blood marker linked to brain damage. The dementia of Parkinson's disease causes memory loss, confusion, hallucinations, and mood changes. About half of those diagnosed with Parkinson's within 10 years, profoundly affecting patients, families and the healthcare system.

Under the direction of cognitive neurologist Dr. Stephen Pasternak's study gave one group daily ambroxol while the other group received a placebo. “Our goal was to change Parkinson’s dementia,” Pasternak says. “This early review offers hope and provides a strong foundation for larger studies.”

Key findings from the clinical trial include:

• Ambroxol was safe, well tolerated and reached therapeutic levels in the brain

• Psychiatric symptoms worsened in the placebo group but remained stable with ambroxol use.

• Participants with high-risk Gba1 gene variants showed improved cognitive performance with ambroxol

• A marker of brain cell damage (GFAP) increased in the placebo group but remained stable with ambroxol, indicating potential brain protection.

Although ambroxol is approved in Europe for the treatment of respiratory conditions and has a long-standing safety record - including use in high doses and during pregnancy - it is not approved for use in Canada or the United States

Current therapies for Parkinson's disease and dementia address symptoms but do not stop the underlying disease. These results suggest that ambroxol may protect brain function, particularly in those at genetic risk. It offers a promising new avenue of treatment where few currently exist. “

Dr. Stephen Pasternak, cognitive neurologist

Ambroxol supports a key enzyme called glucocerebrosidase (GCase), which is produced by the Gba1 gene. Gas levels are often low in people with Parkinson's disease. When this enzyme doesn't function properly, waste builds up in brain cells, causing damage. Pasternak learned about it during a fellowship at the Hospital for Sick Children (Sickkids) in Toronto, where it was identified as a treatment for Gaucher disease - a rare genetic disorder in children caused by a lack of gases.

He is now applying this research to investigate whether boosting gases with ambroxol could protect the brain in Parkinson's-related diseases. “This research is critically important because Parkinson’s dementia profoundly affects patients and families,” says Pasternak. “If a drug like ambroxol can help, it could offer real hope and improve lives.”

Funded by the Weston Foundation, this study is an important step toward developing new treatments for Parkinson's disease and other cognitive disorders, including dementia with Lewy bodies. Pasternak and his team plan to launch a follow-up clinical study focusing on cognition specifically this year.

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