Levodopa, the most common drug used to treat Parkinson's disease, is initially very effective. However, long-term treatment often lessens efficacy and causes multiple complications, including abnormal involuntary movements, called dyskinesias. These uncontrolled movements of the head and limbs tend to worsen over time and can become as debilitating as Parkinson's disease itself. Currently, there are only limited therapeutic options for dyskinesias, including reduction in levodopa dose, amantadine administration, and deep brain stimulation for a limited number of patients.
Most of the research on tobacco has focused on its detrimental health effects. Studies conducted over the last 40 years show that the incidence of Parkinson's disease is about 50 percent less in smokers than in the general population. Recent studies in experimental models suggest that the nicotine in smoke may be responsible for this neuroprotective effect. In addition, this is the first research to show that nicotine may also reduce levodopa-induced dyskinesias. With an estimated 1.5 million Parkinson's disease patients in the United States, and levodopa being the top prescribed medication for Parkinson's disease, this study has far-reaching implications for the treatment of Parkinson's disease.
"Our hope is that this research represents a useful treatment strategy to reduce the dyskinesias that so many Parkinson's disease patients suffer, "said Dr. Maryka Quik of the Parkinson's Institute and Clinical Center in Sunnyvale. "Reducing the side effects of levodopa makes it a much more effective and long-term treatment."