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.
HOW CAN PARKINSON’S DRUGS TRIGGER A GAMBLING HABIT?
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 the role of dopamine, which Parkinson’s patients do not have enough of due to nerve cell damage and which medications aim to boost.
As well as helping to control movement, balance and walking, dopamine plays a role in the part of the brain that controls reward and motivation.
It is known that impulse behaviour, when a person can’t resist the temptation to carry out certain activities, gives instant gratification.
The Greek man’s doctors explain the higher rates of pathological behaviors among patients taking dopamine agonists could be explained by a dopamine receptor in the brain called D3.
D3, a target for drugs which also treat schizophrenia and drug addiction, is stimulated excessively by the drug pramipexole.
This reduces the ability to control impulses by decreasing the interaction between two parts of the brain – the nucleus accumbens and the prefrontal cortex.
The doctors believe the D3 receptor has ‘an important role in modulating the physiologic and emotional experience of novelty, reward and risk assessment’.
Dr Kontoangelos and his team said the prevalence of gambling addiction in patients using dopamine agonists is around two and eight per cent, compared to one per cent of the general population.
They also consider young, male Parkinson’s patients with more than one psychiatric disorder to be most at risk of developing the side effect.
Daiga Heisters, of Parkinson’s UK, said: ‘Our research has shown more and more people feel they are not being given enough information, including about potential side effects, when they start Parkinson’s medication.
‘Equally, many are not being monitored for whether they are starting to develop this behaviour by their healthcare team.’
Pfizer Australia, part of the global pharmaceutical company Pfizer, offered a settlement to patients who developed an addition to gambling and sex after taking medication to treat Parkinson’s disease.
Some 170 patients claimed they were not warned of the side effects of the drug Cabaser between 1996 and 2010.
They were soon gambling away entire life savings or partaking in other extreme behaviours they would not normally.
The confidential settlement, reportedly for millions of dollars, was approved in federal court in Australia in 2015.
Ms Heisters said: ‘Health professionals have a responsibility to raise awareness of these side effects with patients and their carers, and do all they can to mitigate the risks.
‘Pharmaceutical companies also have a responsibility to provide effective information, and work towards medication with less harmful side effects.
‘We would advise anyone who has concerns about taking their Parkinson’s medication to discuss this with their healthcare team.’
WHAT IS PARKINSON’S? THE INCURABLE DISEASE THAT STRUCK BOXER MUHAMMAD ALI
Parkinson’s disease affects one in 500 people, and around 127,000 people in the UK live with the condition.
Figures also suggest one million Americans also suffer.
It causes muscle stiffness, slowness of movement, tremors, sleep disturbance, chronic fatigue, an impaired quality of life and can lead to severe disability.
It is a progressive neurological condition that destroys cells in the part of the brain that controls movement.
Sufferers are known to have diminished supplies of dopamine because nerve cells that make it have died.
There is currently no cure and no way of stopping the progression of the disease, but hundreds of scientific trials are underway to try and change that.
The disease claimed the life of boxing legend Muhammad Ali in 2016.