CBC News - COMPULSIVE GAMBLING SWITCHED ON, OFF WITH PARKINSON'S DRUG: STUDY

WebPosted Mon Jul 11 19:12:02 2005



---A married pastor secretely gambled away about $2,500 and another man had sex four times daily, report doctors describing addictive behaviour

among people treated with a type of Parkinson's drug.



Researchers from the Mayo Clinic in Rochester outline the cases of two women and nine men with Parkinson's who developed pathological gambling

after taking drugs called dopamine agonists.



The drugs work to relieve tremors and stiffness in people with Parkinson's by boosting levels of dopamine in the brain. Dopamine is also

important to the limbic area, which helps control mood and the brain's internal reward system.



In the U.S. and Canada, lawyers are trying to certify class-action lawsuits against drug companies by people who developed compulsive

behaviour while taking the drug pramipexole, sold as Mirapex. The complainants say they weren't warned about the rare side-effect.



FROM MAY 9, 2005: Man claims Parkinson's drug made him gamble The Mayo Clinic case studies not only lend support to the idea the drugs may lead

to behaviour problems, but show the rare side-effect may be reversed "like a light switch being turned off" once people stop taking the drug.



In one report, the wife of a 52-year-old married man phoned the neurologist after her husband lost more than $100,000, had gained 50

pounds from eating compulsively, and was obsessed with sex, engaging in an extramarital affair and pornography.



Within one month of stopping the drug treatment, he lost all interest in gambling and his wife reported she had her "old husband back."



A 50-year-old married man with no history of gambling said he felt "unable to pull myself away from the tables" at the casino. After his

dose was reduced, he stopped gambling and his sex drive dropped to its previous level.



The Mayo doctors saw all of the patients between 2000 and 2002. In eight of the cases, gambling stopped when the drug was reduced or discontinued.

Researchers did not have follow-up information on the other three people.



"Dopamine agonist drugs appear to be uniquely implicated as a cause of pathological gambling," the researchers write in the July 11 online issue

of the Archives of Neurology.



A previous study on more than 500 people estimated only about 1.5 per cent develop addictive behaviour.



The researchers caution people should not panic and stop taking the medication, which has been shown to help Parkinson's symptoms. But

patients and their families should be on the lookout for changes in behaviour.



All commonly prescribed dopamine agonists have been associated with pathological gambling, including the standard Parkinson's therapy,

levodopa, the manufacturer and distributor of Mirapex said in a statement.



The study's authors said pramipexole or Mirapex is "disproportionately represented" in their reports and elsewhere in the medical literature.



The drug's labelling has been updated to advise doctors and patients of the potential side-effect.