A 74-year-old Parkinson's patient became addicted to gambling in a bizarre side effect of his prescribed medication.
The Greek man's desires to use slot machines started a month after his doctor prescribed pramipexole, a dopamine agonist.
Doctors said the unnamed man lost significant relationships because he was lying about his spending and suffered a lack of sleep and appetite.
Dopamine agonist drugs have been shown to cause impulsive and compulsive behaviours in 17 per cent of those who use them.
A Parkinson's charity has now warned patients aren't being told about the possible, and more bizarre, side effects of medications.
A 74-year-old man became addicted to gambling in a bizarre side effect of his prescribed medication, psychiatrists at the University Mental Health Research Institute in Athens report
These behaviours include pathological gambling, hypersexuality, compulsive shopping and eating.
Psychiatrists at the University Mental Health Research Institute in Athens, Greece, published the case study in the journal Scientific Reports.
The man had been diagnosed with Parkinson's five years before, according to Dr Konstantinos Kontoangelos who treated him.
A month after starting the medication, the man increasingly felt a desire to visit the casino until he was going every day.
He was spending more money to achieve instant reward and excitement at the cost of his sleep, appetite and close relationships, although it is not clear what those relationships were.
It is not exactly clear how medications cause changes in behaviour in people with Parkinson's.
Treatment with dopamine-receptor agonists is associated with impulse control disorders, including pathological gambling, binge eating, and hypersexuality.
Common side effects of pramipexole, for example, include abnormal behaviours and appetite, confusion, hallucinations, sleep trouble and psychiatric disorders.
Less common effects are anxiety, binge eating, pathological gambling, pneumonia, sexual dysfunction, hiccups and heart failure.
Research has shown that around 17 per cent of people with Parkinson's who take dopamine agonists experience impulsive and compulsive behaviour.
For a small number of people, other types of Parkinson's medications, in particular levodopa, have also been shown to have similar side effects.
The research suggests that seven per cent of people who take these other kinds of medication are affected.
It should not put you off taking your medication. However, we encourage you to talk to your Parkinson's nurse or specialist about these side effects.
Source: National Institute for Health and Care Excellence and Parkinson's UK.
It is not clear how long his life continued this way, but the report said: 'After the discontinuation of the drug all this behavior was interrupted.'
It's not the first time the side effect has been documented. But experts are still trying to figure out how Parkinson's medication can cause changes to people's behaviour.
However, it could be linked to
