Mary Ann Childers
Reporting

(CBS) CHICAGO A new group of drugs called dopamine agonists are offering help to some people with Parkinson's disease and restless leg syndrome.

But as CBS 2 Medical Editor Mary Ann Childers reports, complaints of unusual side effects have some questioning if this is a risky remedy.

Barbara Hermansen suffered from chronic insomnia caused by restless leg syndrome until her doctor prescribed a drug called Permax. It helped her sleep like a baby, but she says five years later, it turned her life into a nightmare.

"Gambling was always in my brain," she said.

For this Sunday school teacher and suburban mother of two, a trip to Vegas triggered an urge to gamble that she satisfied online. It became an addiction. She maxed out her credit cards, drained her savings and pension accounts, borrowed money and stole it from her husband's wallet. In three years, Barbara lost $600,000.

"I was basically pouring money down the drain," she said.

She tried Gambler's Anonymous, put a lock in her computer, and even had herself banned from Illinois casinos.

"I had my picture taken like a mug shot and signed this thing and said, 'Don't let me on this boat!'"

But she says she was out of control, suicidal. Then, a therapist asked about her medication.

"And I said, 'Oh, wouldn't it be nice to blame it on the medicine.' And he said, 'What are you talking about?' There are case reports from all over the world that link that medicine with compulsive gambling,'" she recalled.

But could medicine really do that?

"The fact that it's the dopamine agonists that apparently seem to trigger these abnormal behaviors is relatively new," said Rush University Medical Center neurologist Leo Verhagen.

Dr. Verhagen says dopamine agonists are mainly used to control the involuntary moments of Parkinson's disease, but they also affect the part of the brain that controls feelings of reward and well-being. Now, growing anecdotal evidence links these drugs to obsessive behaviors, such as compulsive shopping, hyper-sexuality, binge eating and gambling.

"It's much more common than we thought originally," Verhagen said.

It took Barbara four months to wean herself off the medication, but suddenly, she says the urge to gamble was gone.

"I would suffer from insomnia for the rest of my life rather than go through that gambling hell again," Barbara said.

Barbara Hermansen is suing Eli Lilly and the distributor of Permax, Valiant Pharmaceuticals.

Eli Lilly declined comment and referred CBS 2 to Valiant. Valiant declined comment because the case is pending.

It's important to point out dopamine agonists are considered important medicines and lifesavers for some Parkinson's patients because they slow down the progression of the disease.

Reports about behavioral side effects of these drugs have been appearing in medical journals since 2003, but no definitive scientific study has been done and no one knows how many people might be affected.