Dementia remains one of the biggest challenges in healthcare, with no widely available treatments to slow its progression.
But a recent study led by researchers at the Lawson Health Research Institute may offer new hope. They are testing whether Ambroxol, a common cough medicine used for decades in Europe, could help slow the development of dementia in people with Parkinson’s disease.
The 12-month clinical trial, published on June 30 in JAMA Neurology, involved 55 people diagnosed with Parkinson’s disease dementia (PDD). This condition affects memory, mood, and thinking abilities and often leads to confusion and hallucinations. It’s estimated that about half of those diagnosed with Parkinson’s will develop dementia within 10 years.
Dr. Stephen Pasternak, a cognitive neurologist, led the trial. One group of participants took Ambroxol every day, while the other group received a placebo (a harmless fake pill). The researchers tracked participants’ memory, mental health symptoms, and levels of a brain damage marker called GFAP in the blood.
The results were encouraging:
– Ambroxol was safe and well tolerated. It successfully reached the brain at levels high enough to be effective.
– People in the placebo group had worsening psychiatric symptoms, but these symptoms stayed stable in those taking Ambroxol.
– Participants with a high-risk gene variant (GBA1) who took Ambroxol showed improved memory and thinking.
– The GFAP marker increased in the placebo group, indicating more brain damage, but it stayed stable in those on Ambroxol—suggesting that the drug may help protect the brain.
Although Ambroxol is not approved in Canada or the U.S., it has a long safety history in Europe for treating respiratory conditions—even during pregnancy and at high doses.
“Most treatments for Parkinson’s disease and dementia only manage symptoms,” said Dr. Pasternak. “Ambroxol may actually protect the brain, especially for those who have genetic risk factors. This opens the door to a new approach when options are very limited.”
Ambroxol works by helping a key enzyme called glucocerebrosidase (GCase), which is produced by the GBA1 gene. In people with Parkinson’s disease, this enzyme is often at low levels.
Without enough of it, waste builds up in brain cells, causing damage. Pasternak became interested in Ambroxol after learning about its use for Gaucher disease, a rare condition in children that also involves problems with the GCase enzyme.
Now, Pasternak and his team hope Ambroxol could also help people with Parkinson’s-related dementia. “Parkinson’s dementia deeply impacts patients and their families,” he said. “If Ambroxol proves effective, it could bring real relief.”
The study was funded by the Weston Foundation. Next, the research team plans to launch a larger trial later this year, focusing specifically on improving thinking and memory.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more health information, please see recent studies about how wheat gluten might be influencing our brain health, and Olive oil: a daily dose for better brain health..
The study is published in JAMA Neurology.
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