Some info I found online:

GlaxoSmithKline was forced to update its package insert for Requip, a drug used to treat restless legs syndrome (RLS). Requip causes "pathological gambling." Not only Requip causes these unusual side effects, Mirapex, a former Pfizer drug can also make your personality change overnight.

According to the Mirapex package insert, "patients taking certain medicines to treat Parkinson's disease or RLS, including Mirapex have reported problems with gambling, compulsive eating, and increased sex drive."

As upsetting as that is, it's also very exciting! If researchers are able to identify the brain chemistry that causes these specific compulsions, they're a lot closer to figuring out how to treat them. Right now, the vast majority of us are using behavioral changes to manage our impulses, but if we are someday able to physiologically attack the problem too, then we will all have a one-two knockout punch available to us~
It's also interesting that the problems reported have nothing to do with substance abuse, rather the pleasure centers.
My grandfather had Parkinson's, used Mirapex, and I do know that my grandmother was really irritated with his constant advances toward her! He was 86, had previously been very reserved and proper, but all of a sudden turned into a major horndog! We all thought it was part of his developing dementia, but I think it probably was the drug!

In Australia Mirapex is marketed under the name of Sifrol. I have been taking Sifrol for 6 years and have had 100% success in eliminating all RLS symptoms.

However yes you are right the side effects are hideous.

It changes your personality drastically without you realising itm My downfall was obsessiveness once I started something I couldn't stop. I would paint for 6,7, 8 hours straight without even noticing. I didn't gamble with money but money is not the only currency one can gamble with. Increased sex drive .... definitely, but being a 64 year old single woman is easily controllable; if there was something to replace the drug I would gladly give it up but until there is I will continue taking it.

I can control the side effects of the drug but there is no way I can control the symptoms of RLS.

How strange ocd symptoms can be a side affect of a drug. I’ve suffered from depression most of my life and have been on several different antidepressants over the years. In my twenties I suffered from Restless Leg Syndrome and my mom thought it was funny & weird, like it was just me being me. Now it has a name. Every once in a while I’ll feel it still, but not nearly as bad as it was way back when it first began.
I wonder if antidepressants have RLS as a side effect? Why not, eh? The list of side effects is a paper mile long!
DEPRESSION,OCD, RLS, COMPLUSIVE GAMBLER here
Today I will not gamble

Yes, from my other support group members and certain medications for Parkinson's also have a similar effect.