* Drugs raise risk of compulsive gambling, sex, eating
* Study in Parkinson's patients confirms link
* More study needed in restless legs syndrome
By Julie Steenhuysen
CHICAGO, May 10 Parkinson's drugs can triple
the odds that people develop impulse control problems such as
gambling, binge eating, shopping sprees and compulsive sexual
behaviors, U.S. researchers said on Monday.
The study of more than 3,000 people with Parkinson's
disease confirms that so-called dopamine agonists, such as
GlaxoSmithKline's (GSK.L) Requip or ropinirole or Boehringer
Ingelheim's Mirapex or pramipexole, can cause impulse control
And it may mean doctors who prescribe the drugs for other
conditions like restless legs syndrome should watch for these
symptoms in patients, they said.
"For some time now we've suspected there might be an
association between exposure to dopamine agonists and the
development of impulse control problems in patients," said Dr.
Daniel Weintraub of the University of Pennsylvania and the
Philadelphia Veterans Affairs Medical Center, whose study
appears in the Archives of Neurology.
Dopamine agonists work by helping the brain make more
dopamine, the message-carrying chemical made by brain cells
destroyed by Parkinson's. Patients with the incurable disease
have difficulties with movement, muscle control and balance and
can eventually become paralyzed and die.
Weintraub's team studied 3,090 Parkinson's patients. Nearly
all were taking either a dopamine agonist or a levodopa
dopamine replacement drug such as Bristol-Myers Squibb's
They found impulse control disorders in 13.6 percent of
patients taking a dopamine agonist, including compulsive
gambling in 5 percent of patients, compulsive sexual behavior
in 3.5 percent of patients, compulsive buying in 5.7 percent
and binge-eating in 4.3 percent.
And 4 percent of patients had two or more of these
disorders, the team found.
"It confirms that dopamine agonist treatment is associated
with one or more impulse control disorders in patients with
Parkinson's disease," he said.
Weintraub said there was also an association with the
impulsive behaviors in patients taking levodopa, but it was
Weintraub said more study is needed to see whether impulse
control problems occur at the same rates in people who take
dopamine agonists for restless legs syndrome because the drugs
are often given at lower doses.
(Editing by Maggie Fox; Editing by Cynthia Osterman)