The U.S. Food and Drug Administration Wednesday approved the first patch to treat the symptoms of Parkinson's disease.

The patch, called Neupro, is made by German drug firm Schwarz Pharma and delivers the new drug, rotigotine. The Neupro patch is replaced every 24 hours and provides a continuous dose of the drug.

"The drug is a dopamine agonist and is similar to other dopamine agonists that treat Parkinson's," said Dr. C. Warren Olanow, a professor of neuroscience and chairman of the Department of Neurology at Mt. Sinai School of Medicine in New York.

Parkinson's is caused when dopamine-producing cells are mistakenly destroyed in the brain. It is marked by worsening tremors and paralysis. Dopamine agonists provide more dopamine, a message-carrying chemical, to the brain.

"What is different about this new treatment is that it's delivered in a patch instead of an oral formation," Olanow said. "The advantage is that it's more convenient. You put it on one time per day. You don't have to take multiple pills so it's more convenient and compliance will be improved."

The most common side effects for Neupro included skin reactions at the patch site, dizziness, nausea, vomiting, drowsiness and insomnia, most of which are typical of this class of drugs, according to the FDA.

Olanow said the medication may not be right for people prone to skin irritations and the elderly. He said moving the patch around to different parts of the body may reduce the incidence of skin irritation.

"The elderly and people with congnitive impairment are more prone to hallucinations from dopamine agonists and probably shouldn't use the patch," he said. "Also, there are some people who just won't tolerate the patch well, like those with skin conditions, men who are very hairy and people who have sweating conditions."

Like other dopamine agonists, Neupro has a low-incidence of the tremors and shaking that are a side effect of some other kinds of Parkinson's medications, said Olanow.

He said he and other researchers are currently studying the long-term effects of the patch and whether people should keep it on or take it off overnight while sleeping.

"Some people wake up in the morning with very bad symptoms and keeping it on overnight might prevent those symptoms," he said. "But leaving it on may cause people to develop a tolerance to it and that's something we don't want. It's one of those things where (Neupro) is a very good drug. But, by studying it, we can probably make it better."

According to the Parkinson's Action Network, more than one million Americans have Parkinson's disease and 60,000 new cases are diagnosed each year.

(The Associated Press contributed to this story)