Parkinson's Drugs Not to Blame
WebMD News Archive
Jan. 22, 2002 -- In the last couple of years, there has been an explosion in reports of sleep attacks in people being treated for Parkinson's disease. But contrary to what many people are being told, a new study says that new Parkinson's drugs are not the cause.
The first reports of sleep attacks in people with Parkinson's disease surfaced in 1999. And since then, people on the newer Parkinson's drugs -- Mirapex and Requip -- have been warned about getting behind the wheel of a car.
These new drugs belong to a class of medications called "dopamine agonists." Drowsiness is a recognized side effect of these news drugs. But medical research has not been able to determine if these Parkinson's treatments cause sleep attacks and excessive daytime sleepiness.
So researchers at the Winnipeg Clinic in Manitoba, Canada, decided to put this to the test. Their research is featured in the Jan. 23 issue of The Journal of the American Medical Association.
They studied more than 630 people with Parkinson's disease who were otherwise doing well. They evaluated each of them for excessive daytime sleepiness and sudden attacks of sleep. More than 400 of them were drivers.
Excessive daytime sleepiness was seen in 51% of the participants, including the drivers. But people on Mirapex or Requip were not any more likely to have daytime sleepiness. And they were no more likely to fall asleep while driving compared with people not on these drugs. In fact, sleepiness was not associated with any particular type of Parkinson's drug.
Close to 4% of people did experience one episode of a sleep attack while driving. In three of those people, it occurred with no warning at all. Cynthia L. Comella, MD, calls these sleep attacks "exceedingly rare."
But researchers Douglas E. Hobson, MD, and colleagues point out that excessive daytime sleepiness is more common in people with Parkinson's. But the drugs don't appear to affect this significantly.
So why do people with Parkinson's disease have more trouble with daytime sleepiness? Medical research hasn't quite figured that one out. But Comella, who wrote an editorial to the study, points out several factors that may increase sleepiness in people with Parkinson's disease.