Didier Jambart, 51, of Nantes, France, is suing the British pharmaceutical company GlaxoSmithKline, claiming the drug he took to treat his Parkinson's symptoms, Requip, turned him into a gambling and gay sex addict.
The married father of two said he blew through his family's savings and even took to stealing to finance his online gambling habit, the French Press Agency reported. He also became addicted to gay sex and risky sexual encounters that led to him being raped, his lawyers said.
Parkinson's disease destroys neurons deep within the brain that release the "feel-good" neurotransmitter dopamine. Requip belongs to a class of drugs called dopamine agonists that relieve motor symptoms, such as shaking, stiffness, slowness and trouble balancing, by activating dopamine receptors. But the drugs have side effects that, while rare, are serious.
"There are plenty of reports of people developing side effects from Parkinson's drugs, such as hypersexuality, gambling and excessive shopping," said Dr. David Standaert, professor and interim chairman of neurology and director of the Center for Neurodegeneration and Experimental Therapeutics at the University of Alabama at Birmingham. "It's uncommon, but very dramatic when it happens."
Up to 17 percent of people with Parkinson's disease who take dopamine agonists exhibit an impulse control disorder, according to a 2010 study published in the Archives of Neurology.
"It can be devastating for those people," said Dr. Mark Stacy, a neurologist at Duke University Medical Center, who first linked the drugs to gambling in 2000. "And I think that because of the embarassing nature of the complaint, it's a bit amplified."
Jambart is not the first Parkinson's patient to sue a drug maker over these symptoms.
In 2008, a district court in Minneapolis awarded Gary Charbonneau $8.2 million in gambling losses and punitive damages in a suit against the makers of Mirapex, Pfizer and Boehringer Ingelheim.
And in 2010, more than 100 patients in Australia sued Pfizer and Aspen Pharmacare -- the makers of Cabaser and Permax respectively -- over sex and gambling addictions.
"Dopamine is a reward signal," Standaert said, adding that certain illicit drugs, such as cocaine and methamphetamine, act on dopamine receptors. Standaert said he has met patients who have gambled or shopped away hundreds of thousands of dollars.
"In certain individuals who seem sensitive to this, these dopamine agonists really make them overcome their normal inhibitions," Standaert said. "They lose their moral compass."
Compulsive behaviors such as pathological gambling and hypersexuality are now listed as a side effect on the drugs' package inserts. But Jambart claims this wasn't the case when he starting taking Requip in 2003.
By the time he stopped taking Requip in 2005, he had already been demoted at work and suffered psychological trauma because of his addictions, his lawyers told the French Press Agency.
In the United States, GSK added warnings about unusual behaviors to the Requip package insert in July 2005 and expanded them in 2006, according to company spokeswoman Mary Anne Rhyne, who was unable to comment on the timing of the insert update in France.
"We urge patients to talk to their doctor before deciding to stop or start taking any medicine," Rhyne said. "Anyone receiving treatment with dopamine agonists who notices unusual behaviours, such as new or increased gambling urges, increased sexual urges or other intense urges should talk to their doctor."
Although the package insert lists the possible side effects, doctors should make sure patients are aware of them before prescribing the drugs, according to Dr. Joseph Jankovic, professor of neurology and director of the Parkinson's Disease Center and Movement Disorders Clinic at Baylor College of Medicine.
"There's a trade-off between reduction of motor symptoms and the side effects, Jankovic said. "As long as it's discussed and patients and their family are aware, I think most patients will agree that the benefits outweigh the risks."
But if a patient does develop behavioral side effects, they usually have to stop taking the drug. There are other treatment options, such as L-Dopa and deep brain stimulation. But these have risks and side effects too.
As many as 1 million people in the United States have Parkinson's disease, and up to 60,000 new cases are diagnosed every year, according to the National Parkinson Foundation.
With medications like dopamine agonists, newly diagnosed patients can maintain relatively normal lives for 15 years or more, Standaert said. But ultimately, the disease still catches up with them.
"We want to find a way to diagnose Parkinson's disease earlier and find a treatment that actually stops the disease from progressing," Standaert said.
In the meantime, treating the symptoms with drugs like dopamine agonists can help people with Parkinson's disease maintain normal lives, Standaert said.
"These side effects are colorful and serious, but rare," Standaert said. "These are very useful medications. People shouldn't be frightened, they should just know about the risks."