|
 Cases of these severe impulse control disorders linked to the drugs
have been reported for more than 10 years, and in many cases the
abnormal behavior stops when patients stop taking the medications,
lead author Thomas J. Moore of the Institute for Safe Medication
Practices in Alexandria, Virginia, and colleagues write in their
report of the study.
The Parkinson’s Disease Foundation says on its website that in one
earlier study, dopamine agonists were linked with compulsive
behaviors in up to 14 percent of patients.
To further investigate the connection, Moore’s team analyzed 2.7
million serious drug side effects reported in the FDA Adverse Event
Reporting System between 2003 and 2012 in the U.S. and 21 other
countries. They identified 1,580 impulse control disorder events,
710 linked to dopamine agonist drugs and 870 associated with other
drugs.
The dopamine agonists were most often prescribed for Parkinson’s
disease but were also sometimes prescribed for restless leg
syndrome.
Dopamine agonist drugs were 277 times more likely to result in a
report of specific impulse control symptoms than other drugs, Moore
told Reuters Health by email.
“This tells you that reports associating a drug with pathological
gambling or hypersexuality are extremely rare, except for this group
of drugs,” he said.
That’s a large increase in risk, and the actual risk could in fact
be higher, since these data rely on official reports of drug side
effects, according to Joshua J. Gagne of Brigham and Women’s
Hospital and Harvard Medical School in Boston.
Gagne wrote an editorial accompanying the new results, which
appeared online October 20 in JAMA Internal Medicine.
There was also a link between impulse control disorders and
antidepressants or antipsychotics, but not as powerful as the link
with the Parkinson’s drugs.
Dopamine agonist drugs, which include pramipexole (Mirapex),
ropinirole, cabergoline, bromocriptine (Cycloset), rotigotine and
apomorphine (Apokyn) in the U.S., activate dopamine receptors even
in the absence of dopamine itself.
[to top of second column] |
None of these six drugs come with so-called Boxed Warnings about the
potential behavioral side effects, but all six should come with
clear and prominent warnings, the authors write.
Dopamine plays a complex role in regulating behavior, Gagne said,
and drugs that affect the way the brain uses dopamine may reduce the
threshold for impulsive behaviors.
“More and more we are learning what it does,” he said. “It makes
biological sense that this may be causal.”
These compelling results are some of the best evidence we may be
able to get concerning the behavioral consequences of dopamine
agonist drugs, Gagne said. It’s difficult to study because many
patients may not want to disclose their gambling or sexual behavior
problems, he said.
“I think that this is one more piece of the puzzle that there may be
something going on here with these drugs,” Gagne told Reuters Health
by phone.
“Doctors should understand and weigh these risks against the
benefits,” Moore said. “There is a lot of difference between a
patient with advanced Parkinson's disease with severely impaired
motor control and a patient with a mild case of restless leg
syndrome.”
SOURCE: http://bit.ly/1wknEWt
JAMA Intern Med 2014.
[© 2014 Thomson Reuters. All rights
reserved.] Copyright 2014 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
 |
