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Source: Neurology 2001;57:1829-1834. Date: 12-12-2001 http://dailynews.yahoo.com/h/nm/20011212/hl/parkinsons_1.html Wednesday December 12 1:32 PM ET Drug May Relieve Parkinson's Therapy Side Effects NEW YORK (Reuters Health) - The experimental drug sarizotan counteracts some of the debilitating side effects of levodopa, the most commonly used drug for Parkinson's disease, animal studies show. The encouraging results in animals should give the green light for clinical trials of sarizotan and other similar drugs in patients with Parkinson's, according to the study's authors. Parkinson's disease is a progressive neurological disorder that causes tremor, muscle rigidity and movement problems. The main treatment is the drug levodopa, which helps restore diminishing levels of the brain chemical dopamine in Parkinson's patients. But long-term use of the drug often leads to potentially disabling side effects. Many people who take the drug develop dyskinesia, a condition marked by involuntary movements of the mouth, face and limbs. Some research suggests that the complications of levodopa arise in part from an increase in the release of another brain chemical called serotonin. It is ``conceivable,'' according to a team of researchers led by Dr. Francesco Bibbiani and colleagues at the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, that a class of drugs called 5-HT1A agonists might relieve some of the side effects by blocking the release of serotonin. Bibbiani and his colleagues tested one such drug, sarizotan, in rats and monkeys that had Parkinson-like symptoms. Levodopa can relieve such symptoms in rats, but after about 3 weeks, the animals become less responsive to the drug. But when the rats received a single dose of sarizotan after taking levodopa for 23 days, the diminished response was ``virtually reversed,'' Bibbiani and his colleagues report in a recent issue of the journal Neurology. As is the case in people with Parkinson's, monkeys on daily levadopa therapy develop dyskinesias. But Bibbiani and his colleagues found that sarizotan reduced one form of dyskinesia by as much as 91% in monkeys. The results of these animal tests, the authors point out, are consistent with preliminary research showing that the anti-anxiety drug buspirone, which acts on the same pathway as sarizotan, can improve levodopa-related complications in people with Parkinson's disease. Based on the apparent safety and effectiveness of sarizotan in animals, clinical trials of sarizotan and other similar drugs ``appear warranted,'' the authors conclude. Merck, the company that is developing sarizotan, provided the drug for the study. ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn