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Source: The Oregonian OHSU finds new aid for Parkinson's Researchers say the drug Ritalin appears to boost the efficacy of the main Parkinson's drug and help patients with movement Saturday, May 08, 2004 ANDY DWORKIN The drug Ritalin, often prescribed to hyperactive children, may help adults fight the tremors and movement problems of Parkinson's disease, say Oregon Health & Science University researchers. small experiment found Ritalin alone did not affect Parkinson's, said Dr. John Nutt, the OHSU neurologist who led the research. But a high dose of Ritalin seemed to enhance the effects of levadopa, or "L-dopa," the main drug used to treat Parkinson's. Nutt and colleagues gave 14 Parkinson's patients L-dopa every two hours, as is common, but occasionally added Ritalin. A dozen of the patients responded to the two-drug combination, but only five responded well to the L-dopa alone. The Ritalin also lengthened L-dopa's effects, as measured by tests of everyday movements such as walking and turning. "You could probably give smaller doses" of L-dopa by adding Ritalin, Nutt said, "and have the effect last longer." Nutt cautioned that the study does not prove that benefit -- it only suggests it. He plans to study whether the benefit continues if patients take Ritalin several times every day, as they take L-dopa. However, the initial study, presented last week at a professional conference, gives definite insight to the workings of a brain attacked by Parkinson's. Parkinson's destroys brain cells that produce dopamine, a chemical that sends signals through the brain. The resulting loss of dopamine interferes with normal brain functions, especially those controlling movement. The disease, which usually hits older adults, can cause tremors, rigid muscles, slow movement and balance problems. L-dopa helps because the brain chemically changes that drug into dopamine. Some of the dopamine cells survive Parkinson's, however, and Nutt wanted to see what roles they play in patients. That curiosity led him to methylphenidate, the drug sold as Ritalin. Ritalin blocks the "dopamine transporter," the biological door that lets dopamine into the surviving nerve cells. The absorbed dopamine becomes trapped and can't help Parkinson's brains signal normally. Ritalin's ability to enhance L-dopa shows that the surviving cells can absorb enough dopamine to interfere with L-dopa's benefits, Nutt said. The fact that Ritalin alone does not ease the illness shows that a brain hit by Parkinson's cannot make enough dopamine to govern itself, even with help, and needs the assist from L-dopa. Nutt said other drugs have the same effect as Ritalin (including cocaine), and drug companies are searching for longer-lasting medicines of this kind. Those could prove useful for Parkinson's patients. In a related study, Nutt and colleagues gave 14 Parkinson's patients the antidepressant paroxetine, sold as Paxil. That drug keeps a different set of nerves from absorbing serotonin, another chemical messenger. Some scientists thought those cells also might absorb some dopamine. But the antidepressant had no effect on the patients. Nutt said the study indicates such antidepressants are safe for Parkinson's patients, who commonly develop depression. At least a half-million U.S. residents have Parkinson's, including such well-known people as former U.S. Attorney General Janet Reno and actor Michael J. Fox. Andy Dworkin: 503-221-8239; [log in to unmask] http://www.oregonlive.com/news/oregonian/index.ssf?/base/news/10840176002 20270.xml ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn