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Skin Patch Shows Promise For Controlling Parkinson's ... Steady Delivery Of Drug Is Key By JOHN FAUBER [log in to unmask] Posted: Dec. 25, 2003 A new skin patch to treat Parkinson's disease safely released a new drug and significantly improved symptoms, according to a study by researchers at the Medical College of Wisconsin and several other institutions. By using a transdermal patch instead of conventional oral medication, doctors hope to get better control of Parkinson's symptoms while avoiding side effects. One problem with oral Parkinson's drugs is that levels of the drugs can vary substantially from hour to hour depending how often the drugs are taken and how quickly they are cleared from the body. By using a patch, patients can obtain a "steady state" of a drug, said the study's lead author, Karen Blindauer, an assistant professor of neurology and director of the movement disorders program at the Medical College of Wisconsin. That's important because if drug levels are too high, it can cause involuntary twitching or jerking; and if levels are too low, symptoms can worsen, she said. In addition, it is hoped that applying a patch once a day will help patients more closely comply with their medication regimen, Blindauer said. "It's easier to take the (patch) medication compared to if you have to take medication three or four times a day," Blindauer said. Parkinson's is caused by the loss of brain cells in the mid-brain region known as the substantia nigra. Those brain cells produce the neurotransmitter dopamine. Without adequate dopamine levels, neurons can fire out of control, resulting in a lack of control of movement. The most common symptoms are trembling; rigidity in the arms, legs and trunk; slowness of movement such as while walking; and a lack of balance and coordination. While there is no cure for the disease, several oral medications can help control symptoms and most patients can maintain a high level of daily function throughout their lives, according to the National Parkinson Foundation. About 1.5 million Americans have the disease, which tends to be more common among people older than 60, according to the foundation. Drug doses pose problems Dosing of drugs long has been a problem for Parkinson's patients, said Erwin Montgomery, a professor of neurology and director of the movement disorders program at the University of Wisconsin-Madison. "With a lot of (oral) medications, they just go up and down in the bloodstream too quickly," he said. It is believed that the cyclical variation in drug levels also contributes to motor complications and as well as a weakening of the effectiveness of the drugs. Earlier this year, Titan Pharmaceuticals, in a National Institutes of Health sponsored study, reported promising results from a monkey trial using a device that is implanted under the skin to release a Parkinson's drug over a period of six months. Time-released oral medications also have been tried, but even those do not produce perfect results, he said. The idea of a patch has some potential advantages, Montgomery said. "We can bypass the mouth and stomach by applying a patch," he said. "It does give us other options." However, he said, a potential disadvantage of a patch is that it makes it more difficult to regulate drug levels throughout the day, which sometimes is necessary. For instance, some patients may take a pill every hour while others take one every eight hours, he said. And those intervals can change over periods as short as six months to a year. "You really are at the mercy of the time control of the patch," he said. Eventually, a patch might be found to work best in combination with an oral medication, he said. Drug combination Many Parkinson's patients are treated with the so-called gold standard combination of levodopa, which the brain converts into dopamine, along with carbidopa, a drug that helps control nausea and allows for a higher dose of levodopa. Another class of drugs known as dopamine agonists may be used instead, especially in younger patients. Dopamine agonists mimic the effects of dopamine in the brain. The new study used the drug rotigotine, a new dopamine agonist administered via an abdominal patch. The study, which involved 242 patients, appeared in the December issue of the Archives of Neurology. The study compared various doses of rotigotine via a patch to a placebo patch. The study was funded by Schwarz Pharma Inc., the drug's maker. The study found that the transdermally administered rotigotine achieved results similar to two other oral dopamine agonists based on a traditional Parkinson's scoring system. However, because the patch was compared with a placebo, it is not known how it would compare in a head-to-head trial with orally administered Parkinson's drugs. The patch drug also resulted in at least one "adverse" event, such as nausea, vomiting, fatigue and drowsiness, during the 14-week trial in 91% of patients. The study's authors said some events were similar to sudden "sleep attacks" reported with other dopamine agonist drugs. From the Dec. 26, 2003 editions of the Milwaukee Journal Sentinel SOURCE: The Milwalkee Journal Sentinel http://www.jsonline.com/alive/news/dec03/195309.asp * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn