SUNDAY, Feb. 20 (HealthDay News) -- Taking prescription
amphetamines may raise your risk of developing Parkinson's disease
later, new research suggests.
But, the researchers noted that the study did not prove a
cause-and-effect relationship and further investigation is
Study author Stephen K. Van Den Eeden, a senior investigator at
the Division of Research at Kaiser Permanente Northern California,
in Oakland, said that people who reported using Benzedrine or
Dexedrine at some point in their lives showed a 60 percent greater
chance of developing the neurological disorder when compared to
those who said they had never taken the medications.
"We already know that there are certain risks of amphetamine use," Van Den Eeden said. "This is one concern that is unproven, but we need to take into consideration whether the benefits outweigh the known risks, and maybe potential risks."
Amphetamines affect the release and absorption of dopamine, a
key neurotransmitter implicated in the development of Parkinson's
disease, according to background information in the report. They
are commonly prescribed for the treatment of attention-deficit
hyperactivity disorder (ADHD), traumatic brain injuries and a
chronic sleep disorder known as narcolepsy. These medications were
also being routinely prescribed for weight loss when the research
Between 1964 and 1973, 66,348 study participants answered two
questions concerning amphetamines: The first asked if the person
had ever taken weight-loss drugs in general, while the second asked
about the use of Benzedrine and Dexedrine in particular. After
1995, researchers followed up on the participants and found that
1,154 had been diagnosed with Parkinson's. The mean follow-up
period was 38.8 years. While those who said they had taken
Benzedrine or Dexedrine showed an increased risk for being
diagnosed with Parkinson's, those who simply said they had taken
weight-loss drugs in general did not.
Dr. Stacy Horn, an assistant professor of clinical neurology at
the University of Pennsylvania's Parkinson's Disease & Movement
Disorders Center in Philadelphia, explained that patients and
doctors considering prescription amphetamine use should consider
the risk-vs.-benefit ratio.
"Someone who failed all the other classic medicines might consider drugs such as amphetamines," said Horn, who added that further research on the possible connection to Parkinson's is needed.
"We need to confirm the science," said Horn. "There needs to be some increased surveillance. We should look at patients that have had an addiction, and see if there's an increased risk in those populations."
Horn also emphasized that researchers still don't understand
what factors might explain the development of Parkinson's disease,
although previous research has hinted at a link to exposure to
"Part of the problem," Horn explained, "is not knowing if this is a direct correlate or exposure to something else."
The research was released Feb. 19, and is scheduled to be
presented in April at the American Academy of Neurology's annual
meeting in Honolulu.
Since this study is slated to be presented at a medical meeting,
the data and conclusions should be considered preliminary until
published in a peer-reviewed journal.
Find out more about Parkinson's disease at the
U.S. National Institute of Neurological Disorders and