Parkinson’s drug shows promise in helping smokers kick the habit

Ask any smoker who has tried to quit and they’ll tell you it isn’t easy. But a recent study offers a surprising glimmer of hope – one that may already be sitting on pharmacy shelves.

A team of researchers in South Korea at the Korea Institute of Science and Technology has discovered that a Parkinson’s disease drug may effectively ease the physical symptoms of nicotine withdrawal, a development that could significantly boost the success rate of smoking cessation.

According to the World Health Organization, more than 22% of the global population smokes, contributing to over 9 million deaths each year. While two prescription drugs – Bupropion and Varenicline – are currently approved for nicotine withdrawal management, researchers say these treatments don’t work for everyone, and relapse remains common.

Brain activity

When a smoker tries to quit, their brain doesn’t make it easy. Certain regions become hyperactive, triggering symptoms like tremors and decreased physical activity—distress signals that often send former smokers back to their habit.

Researchers zeroed in on a specific brain circuit that appears to be behind these symptoms: the striatal cholinergic interneurons. In animal studies, the researchers selectively silenced sodium channels in these neurons, dramatically reducing the withdrawal tremors in mice. Using advanced neural imaging and electrode mapping, they confirmed that dampening activity in this region effectively neutralized the abnormal brain signaling triggered by nicotine withdrawal.

An analysis of the results showed something even more compelling. Nicotine withdrawal had slashed dopamine levels in the striatum by more than 20%, a neurotransmitter drop closely tied to physical withdrawal symptoms. But when the cholinergic interneurons were suppressed, dopamine levels bounced back to normal.

Old drug, new purpose

Here’s where the study takes a particularly intriguing turn: The researchers found that Procyclidine, a drug currently approved by the FDA to treat Parkinson’s disease, mimicked the effects of neural suppression in these interneurons.

In mice, a single low dose of Procyclidine administered before nicotine withdrawal reduced tremors by over 50%. That’s not just a measurable impact—it’s a potentially transformative breakthrough in how nicotine addiction is treated.

What makes this approach especially promising is its speed to market. Because Procyclidine is already approved and well-studied, repurposing it for smoking cessation could slash the time and cost of clinical trials, making the therapy more accessible to smokers who need alternatives, the researchers said.

The findings were published in the peer-reviewed journal Advanced Science, and the research was supported by Korea’s Ministry of Science and ICT and the Food and Drug Safety Research Project.