Some readers will have already come across reports suggesting that some drugs for Parkinson's disease can lead to odd behavioral problems, including compulsive gambling. Given their effects on dopaminergic pathways, which seem to be involved in stimulus/reward behavior, it's a believable effect. (Actually, as I mentioned the other day, just about anything is a believable side effect with CNS drugs, especially at low rates of incidence).
Now (via Overlawyered) comes a case from Texas. A (once)-wealthy retiree named Max Wells is suing GlaxoSmithKline over their Requip drug (ropinirole), claiming that he wasn't warned that the drug could cause compulsive behavior. His particular compulsive behavior took place in Las Vegas, a city well equipped for it, and involved the loss of some 14 million dollars.
As the Austin newspaper story has it, Wells had started on another Parkinson's drug, Mirapex, in 2004 and lost several thousand dollars gambling, both online and in Vegas. (As it turns out, Boehringer Ingleheim is being sued over that drug, too, for similar reasons). He told his doctor about the problem, and was switched to Requip, which is when things apparently really started to roll.
Wells is also suing at least seven casinos, claiming that they knew that he was taking Parkinson's medication and should have been aware that he had a problem. I think these suits have even less of a chance, because casinos have been sued many times on similar "they should have stopped me" grounds. I recall a Philadelphia businessman in the early 1990s who took an Atlantic City casino to court because of his losses at his favorite game, which was high-stakes blackjack played with the aid of a bottle of bourbon. The casino, he contended, knew that he was impaired and should never have allowed him to continue. This argument didn't make much headway, as you'd probably guess.
This Parkinsonian case is a bit different, but I don't think it's going to get very far. It might bring up interesting questions about free will and human behavior, but no court is going to want to wade into that philosophical swamp. If the facts are as stated, the case will surely be decided on more practical grounds: why Wells didn't go back to his doctor when he started compulsively gambling again on the new medication instead of spending the next several months ripping through millions of dollars, and how casinos are not required to evaluate the motives of their customers.