A decades-old cough medicine could hold new hope in the fight against dementia. A new Canadian-led study is exploring whether a drug widely used in Europe could slow memory loss in people with Parkinson’s disease. Dementia is one of the biggest challenges in health care today, and for those with Parkinson’s disease, the risk is even greater. Roughly half will develop dementia within a decade of their diagnosis. Now, researchers at Lawson Health Research Institute in London, Ont., are looking at a surprising candidate to slow that decline. It’s called Ambroxol, a common cough medicine used safely for decades in Europe. The year-long clinical trial, published today in JAMA Neurology, followed people living with Parkinson’s disease dementia. “We randomized 55 patients to Ambroxol, or placebo for a year. We saw that patients on the placebo had worsening of psychiatric symptoms,” explained Dr. Stephen Pasternak, a cognitive neurologist and study lead. “We saw a small subgroup of patients have improvements in cognition. And we saw that patients on placebo had worsening of a particular brain enzyme in their blood, called GFAP, that we use as a proxy for neurodegeneration.” Ambroxol is not approved in Canada or the U.S., but it’s long been used safely in Europe, even at high doses and during pregnancy. It supports a critical brain enzyme called GCase, often lacking in Parkinson’s patients. “All of our medications for cognition and Parkinson’s disease right now treat the symptoms. They don’t prevent the worsening of the underlying disease. And our hope is if we can identify people before they have symptoms, then we can give them a safe, easy way to take medication, which would prevent the development of these diseases,” explained Dr. Pasternak. Dr. Pasternak first learned about Ambroxol during a fellowship at SickKids Hospital in Toronto, where the drug was used to treat Gaucher disease, a rare childhood disorder. He’s now applying that knowledge to brain diseases in adults, in hopes an old drug might offer new possibilities. Researchers say more studies are needed, but the findings mark a hopeful step toward a safe, affordable treatment that could change the outlook for thousands of Canadians.
