Although a cough medicine called Ambroxol is approved in Europe for treating respiratory conditions and has a long-standing safety record, including use at high doses and during pregnancy, it is not approved for any use in the United States or Canada.
Ball-and-stick model of ambroxol molecule. Image credit: Marina Vladivostok / ChemSpider.
Parkinson’s disease dementia causes memory loss, confusion, hallucinations and mood changes.
About half of those diagnosed with Parkinson’s develop dementia within 10 years, profoundly affecting patients, families and the health care system.
“Our goal was to change the course of Parkinson’s dementia,” said Dr. Stephen Pasternak, a cognitive neurologist at Parkwood Institute, St Joseph’s Health Care London and Robarts Research Institute.
“This early trial offers hope and provides a strong foundation for larger studies.”
The 12-month clinical trial involved 55 participants with Parkinson’s disease dementia.
The authors gave one group daily Ambroxol while the other group received a placebo.
They monitored memory, psychiatric symptoms and GFAP, a blood marker linked to brain damage.
According to the team, Ambroxol was safe, well-tolerated and reached therapeutic levels in the brain.
Psychiatric symptoms worsened in the placebo group but remained stable in those taking Ambroxol.
Participants with high-risk GBA1 gene variants showed improved cognitive performance on Ambroxol.
GFAP increased in the placebo group but stayed stable with Ambroxol, suggesting potential brain protection.
“Current therapies for Parkinson’s disease and dementia address symptoms but do not stop the underlying disease,” Dr. Pasternak said.
“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 supports a key enzyme called glucocerebrosidase (GCase), which is produced by the GBA1 gene.
In people with Parkinson’s disease, GCase levels are often low. When this enzyme doesn’t work properly, waste builds up in brain cells, leading to damage.
“This research is vital because Parkinson’s dementia profoundly affects patients and families,” Dr. Pasternak said.
“If a drug like Ambroxol can help, it could offer real hope and improve lives.”
The results appear in the journal JAMA Neurology.
_____
Carolina R. A. Silveira et al. Ambroxol as a Treatment for Parkinson Disease Dementia: A Randomized Clinical Trial. JAMA Neurol, published online June 30, 2025; doi: 10.1001/jamaneurol.2025.1687
This was shown first on: https://www.sci.news/medicine/ambroxol-parkinsons-dementia-14031.html
