Parkinson's disease is a condition where dopamine nerve cells decrease, causing tremors in the hands and feet and making walking heavy./Courtesy of pixabay

A study has found that the ingredients in cold medicine can help patients with Parkinson's disease-related dementia. Parkinson's disease is a degenerative disorder characterized by the deterioration of dopamine nerve cells in the brain that control unconscious muscle movements. The body trembles, movement becomes heavy, and severe cases can result in cognitive dysfunction.

Dr. Carolina Silveira and her team at the Canadian Centre for Neurology and Alzheimer’s Research said on the 8th, "The ingredient ambroxol in cold medicine has been shown to have therapeutic effects on patients with Parkinson's disease-related dementia." Ambroxol is an expectorant that thins sticky mucus, making it easier to expel. The study was published in the Journal of the American Medical Association (JAMA Neurology) on the 30th of last month.

The research team conducted a clinical trial over 52 weeks involving 55 patients aged 50 and older with Parkinson's disease-related dementia. Among the patients, 31 received ambroxol, while 24 were given a placebo. Dementia patients who took the placebo experienced worsening symptoms, but those who received ambroxol showed no significant changes.

The researchers explained that the activation of the enzyme glucocerebrosidase in the brain occurred when Parkinson's disease-related dementia patients took ambroxol. Parkinson's disease is linked to the excessive accumulation of alpha-synuclein protein in the brain, and glucocerebrosidase is said to prevent this. The research team noted, "When glucocerebrosidase increases, alpha-synuclein decreases."

However, ambroxol only prevented the deterioration of symptoms in Parkinson's disease-related dementia patients and is not a fundamental treatment. The research team stated, "The direct effects of ambroxol on cognitive function in patients have not been confirmed."

References

JAMA Neurology (2025), DOI: https://doi.org/10.1001/jamaneurol.2025.1687