A safe and affordable treatment to slow the advancement of Parkinson’s dementia has emerged – in the form of a commonly available cough syrup that’s already being studied for its positive effect on other degenerative diseases.
Researchers at St Joseph’s Health Care London’s Lawson Research Institute have released the results of a 12-month clinical trial investigating the cough medicine Ambroxol and its potential to slow Parkinson’s-related dementia. In the study, 55 patients with Parkinson’s disease dementia (PDD) were given either a daily dose of Ambroxol or a placebo and had their memory, psychiatric symptoms and the brain-damage blood marker GFAP monitored.
“Our goal was to change the course of Parkinson’s dementia,” said study lead Dr Stephen Pasternak, a cognitive neurologist at Lawson. “This early trial offers hope and provides a strong foundation for larger studies.”
The results deemed Ambroxol to be safe, well tolerated and able to achieve targeted therapeutic significance in the brain. GFAP levels were stable in the Ambroxol group, while these brain-damage markers increased in the placebo cohort. The placebo group also experienced worsening psychiatric symptoms. And those with high-risk GBA1 gene variants also showed “improved cognitive perdformance” on the drug.
“Current therapies for Parkinson’s disease and dementia address symptoms but do not stop the underlying disease,” said Pasternak. “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.”
PDD, much like other forms of dementia, comes with memory loss, hallucinations, confusion and mood shifts. Around half of all Parkinson’s sufferers will go on to develop disease-related dementia within 10 years.
Ambroxol is at the center of another Parkinson’s study, which isn’t linked to dementia outcomes but a rare genetic condition known as Gaucher disease, and the Phase III two-year trial results are due out sometime in 2025. Meanwhile, Australian researchers are currently investigating Ambroxol for the treatment of motor neurone disease (MND), and more specifically Amyotrophic Lateral Sclerosis (ALS).
Of particular interest to Pasternak and team is how Ambroxol supports glucocerebrosidase (GCase), an important enzyme produced by the GBA1 gene. In Parkinson’s sufferers GCase levels are often low, which can result in waste building up in the brain and inflicting damage. Raising those levels helps mitigate that process and shields brain cells from damage.
This medicine, which is used to break down and clear mucus from the respiratory system, is widely available as a cough syrup in Europe. Unfortunately, Ambroxol isn’t approved for human use in the US, Canada or Australia, where it’s only available for scientific study. However, some regions have approved it as a veterinary medicine to treat sick horses and dogs.
It’s widely regarded as safe over-the-counter cold medicine in countries that it’s approved in, helping treat coughs and bronchitis by thinning and clearing mucus from airways. But this latest study suggests it has broader application – although more research is needed.
“This research is vital because Parkinson’s dementia profoundly affects patients and families,” said Pasternak. “If a drug like Ambroxol can help, it could offer real hope and improve lives.”
The study was published in the journal JAMA Neurology.
Source: Lawson Research Institute
