Pathological gambling, hypersexuality and compulsive shopping are some of the abnormal behaviors that are linked to the use of certain drugs commonly used to treat Parkinson's disease, according to a new study. 
 
 The findings are important because they mean that doctors and patients should be wary of the drugs' side effects, according to the study authors. But they also give researchers a better understanding of how abnormal behaviors develop in general, and how such behaviors may be related to the brain receptor that is targeted by the drug, the authors said. 
 
 "In our view, these medications should be used less frequently and with great caution, paying close attention to possible untoward effects on behavior and impulse control," said Dr. Howard D. Weiss of Sinai Hospital of Baltimore and Dr. Gregory M. Pontone of Johns Hopkins University School of Medicine in Baltimore, Maryland, writing in an editorial about the new study. 
 
 In the study, the researchers examined 1,580 reports of people in the United States and 21 other countries experiencing pathological gambling, hypersexuality, compulsive shopping or other abnormal behaviors after taking medication between 2003 and 2012. They found that 710 of the cases occurred in people taking drugs called dopamine receptor agonists, which are used to treat Parkinson's disease, whereas the other 870 cases occurred in people taking all of the other types of drugs combined. 
 
 The researchers determined that the proportion of such reports was 277.6 times higher for people taking dopamine agonist receptor drugs than those taking other drugs. [7 Bizarre Drug Side Effects] 
 
 Dopamine is a neurotransmitter in the brain that normally helps regulate movement, emotions and the feelings of pleasure. In people with Parkinson's disease, the brain cells that make dopamine die over time. Dopamine receptor agonists are used to mimic the function of the neurotransmitter. 
 
 The important step to take after the new findings is to introduce warnings about the potential side effects of those drugs so that doctors who prescribe them are aware of them, said study author Thomas J. Moore, a senior scientist at the Institute for Safe Medication Practices in Alexandria, Virginia. 
 
 "They [doctors and caregivers of Parkinson's patients] need to be on the lookout for this kind of behavior" and understand it may be linked to the use of medication, Moore told Live Science. 
 
 Of all the cases of abnormal behavior that were observed in the people taking the drugs for Parkinson's disease, the majority (410 cases) occurred in those who had been taking a dopamine receptor agonist drug called pramipexole, which affects a receptor called dopamine D3 receptor. And the drug that was second-most commonly linked to such behaviors was ropinirole, which also has a significant effect on the D3 receptor, according to the study, published today (Oct. 20) in the journal JAMA Internal Medicine 
 
 The researchers noted that in some cases, the people taking these drugs had restless leg syndrome (not Parkinson's disease). 
 
 The new research may allow researchers to better understand how abnormal behaviors develop, and how they may be related to the D3 receptor, Moore said. The D3 receptor has also been investigated as a possible target for treatments for people with addictions, the researchers wrote in the study. 
 
 In another study, published in July 2011 in the journal Physiology & Behavior, other researchers also found a link between behaviors such as hypersexuality or excessive gambling and the use of the two drugs that Moore found to be the most closely related to abnormal behaviors in the new study. 
 
 Drugs for Parkinson's have been down this road before. In the 1960s, the introduction of the Parkinson's drug levodopa enabled Parkinson's patients to “regain function and return to the mainstream of life," Weiss and Pontone wrote. 
 
 Levodopa gets converted into dopamine in the brain, said Weiss and Pontone, who were not involved with the new research. 
 
 However, enthusiasm for that treatment was tempered when patients taking it developed involuntary muscle movements, similar to tics, and in rare cases also developing abnormal behaviors such as hypersexuality, they wrote. 
 
 The newer class of Parkinson's drugs — the dopamine receptor agonist drugs — act differently in the brain, Weiss and Pontone wrote. Levodopa gets converted into dopamine in the brain, the dopamine receptor agonist drugs just mimic the neurotransmitter's effects. 
 
 It was known that the dopamine receptor agonist drugs caused side effects such as hallucinations, psychosis and excessive daytime sleepiness. But despite these effects, the drugs remain widely used, and it is only recently that doctors started recognizing a link between the use of those drugs and the occurrence of impulse control disorders with symptoms such as pathological gambling, hypersexuality and uncontrollable spending, Weiss and Pontone wrote. 
 
 It is not surprising that it took a while for doctors to start recognizing the link between the two, they wrote, as they did not routinely inquire about the potentially behavior-altering effects of the drugs. 
 
 "During an office visit, a patient is unlikely to spontaneously mention, 'By the way, doctor, I lost $250,000 in casinos last year, and I purchase $500 of lottery tickets every week' or 'I spend all night on Internet pornography sites and am soliciting prostitutes,'" Weiss and Pontone noted. 
 
 "In summary, physicians have overestimated the benefit and underestimated the risks associated with the use of dopamine receptor agonist drugs in patients with Parkinson disease," they wrote. 
 
 Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science. ||||| Treatments 
 
 Parkinson's Drugs Can Be A Gateway To Sin 
 
 i itoggle caption ImageZoo/Corbis ImageZoo/Corbis 
 
 Drugs that are commonly prescribed to help people cope with Parkinson's disease have been linked to bizarre changes in behavior that patients and doctors should be on guard against, researchers say. 
 
 The disturbing side effects include compulsive gambling, uncontrollable shopping and a sudden obsession with sex. 
 
 The problems with the drugs, called dopamine agonists, are serious enough that the researchers say the Food and Drug Administration should require the medicines to carry what's called a black-box warning, one of the most prominent and serious cautions used for prescriptions drugs. 
 
 Some of the drugs are also prescribed for restless leg syndrome and hyperprolactinemia, a hormonal condition that can trigger milk production. 
 
 While the problems with the dopamine agonists have been noted in the past, the recommendation for a more prominent warning comes come after researchers sifted through 2.7 million reports of drug reactions submitted to an FDA database between 2003 and 2012. 
 
 The researchers from the Institute for Safe Medicine Practices, Harvard and the University of Ottawa found 1,580 adverse drug events involving impulse control disorders. A little less than half, or 710 reports, were associated with dopamine receptor agonist drugs. 
 
 The link was strongest for pramipexole, brand name Mirapex, and ropinirole, brand name Requip. The instructions for doctors who are thinking about prescribing Mirapex already carry a warning that says patients taking the medicine "may experience compulsive behaviors and other intense urges." Requip, a treatment for restless leg syndrome. 
 
 The results were published online Monday by JAMA Internal Medicine. 
 
 Back in 2005, doctors from the Mayo Clinic reported 11 cases of patients who became compulsive gamblers after taking dopamine agonists. A 52-year-old man lost $100,000 in casinos after previously gambling only once in his life. He also became fixated on pornography and obsessed with sex, carrying on extramarital affairs. A month after stopping the drug, he was his old self. 
 
 Doctors and patients may have overlooked the problems. In a commentary accompanying the latest findings, two Johns Hopkins doctors wrote that nausea, dizziness and other physical side effects are more typical parts of the conversations between doctors and patients about drugs. "During an office visit, a patient is unlikely to spontaneously mention, 'By the way, doctor I lost $250,000 in casinos last week' or 'I spend all night on Internet pornography sites and am soliciting prostitutes,' " they wrote. 
 
 Neurologist Howard Weiss, a co-author of the commentary, tells Shots that these drug-related compulsive behaviors haven't gotten the attention in the medical community that they deserve. A heightened warning in the drugs' instructions could help make the risk clearer, Weiss says. The behavioral problems, he says, "are more important than 99 percent of the other side effects that are being listed." 
 
 Weiss says he's had at least three patients who have lost their homes because of bankruptcy after taking the drugs. 
 
 When he asked an elderly patients taking one of the drugs if she ever gambled, she replied, "Gambling is the work of the devil." But it turned out she had been buying hundreds of dollars' worth of lottery tickets a week, a habit she didn't consider to be gambling. 
 
 Weiss says the behavioral problems usually go away after patients stop taking the medicines. He also says the drug combination carbidopa-levodopa, another Parkinson's treatment, works better and doesn't increase the risk for impulsive behavior. ||||| Importance Severe impulse control disorders involving pathological gambling, hypersexuality, and compulsive shopping have been reported in association with the use of dopamine receptor agonist drugs in case series and retrospective patient surveys. These agents are used to treat Parkinson disease, restless leg syndrome, and hyperprolactinemia. 
 
 Objectives To analyze serious adverse drug event reports about these impulse control disorders received by the US Food and Drug Administration (FDA) and to assess the relationship of these case reports with the 6 FDA-approved dopamine receptor agonist drugs. 
 
 Design, Setting, and Participants We conducted a retrospective disproportionality analysis based on the 2.7 million serious domestic and foreign adverse drug event reports from 2003 to 2012 extracted from the FDA Adverse Event Reporting System. 
 
 Main Outcomes and Measures Cases were selected if they contained any of 10 preferred terms in the Medical Dictionary for Regulatory Activities (MedDRA) that described the abnormal behaviors. We used the proportional reporting ratio (PRR) to compare the proportion of target events to all serious events for the study drugs with a similar proportion for all other drugs. 
 
 Results We identified 1580 events indicating impulse control disorders from the United States and 21 other countries:710 fordopamine receptor agonist drugs and 870 for other drugs. The dopamine receptor agonist drugs had a strong signal associated with these impulse control disorders (n = 710; PRR = 277.6, P < .001). The association was strongest for the dopamine agonists pramipexole (n = 410; PRR = 455.9, P < .001) and ropinirole (n = 188; PRR = 152.5, P < .001), with preferential affinity for the dopamine D 3 receptor. A signal was also seen for aripiprazole, an antipsychotic classified as a partial agonist of the D 3 receptor (n = 37; PRR = 8.6, P < .001). 
 
 Conclusions and Relevance Our findings confirm and extend the evidence that dopamine receptor agonist drugs are associated with these specific impulse control disorders. At present, none of the dopamine receptor agonist drugs approved by the FDA have boxed warnings as part of their prescribing information. Our data, and data from prior studies, show the need for more prominent warnings.
– Parkinson's drugs are known for a range of side effects, including hallucinations, psychosis, and extreme drowsiness. But researchers say there's also a clear link between the use of some of these drugs and impulse control issues that result in hypersexuality, compulsive gambling, and uncontrollable spending, reports LiveScience. Looking at 1,580 reports of people in 22 countries, including the US, who'd experienced these abnormal behaviors after taking meds between 2003 and 2012, they identified 710 cases that involve dopamine receptor agonists, drugs often used to treat Parkinson's disease. (The other 870 cases accounted for all other types of drugs combined.) "Physicians have overestimated the benefit and underestimated the risks associated with the use of dopamine receptor agonist drugs in patients with [Parkinson's] disease," the researchers write in JAMA Internal Medicine. One of the writers says three of his patients have lost their homes because they went bankrupt after taking the drugs, reports NPR. The link was strongest for pramipexole (brand name Mirapex) and ropinirole (Requip). Because people taking this type of drug were 277 times more likely to report these impulsive behaviors than those taking other drugs, the researchers are calling for black-box warnings—reserved for the most extreme cautions—detailing the risks involved. (One woman has even reported her Parkinson's meds give her three to five unwanted orgasms daily.)