The NHS drugs that can trigger sex and gambling addictions: One dad lost £100,000 on bets after taking pills to help ease restless leg syndrome – and doctors are STILL prescribing them

Experts have alerted patients with restless leg syndrome over a bizarre side-effect of drugs that treat the condition.

The medicines – known as dopamine agonists – are offered on the NHS, but can cause some people to develop compulsive gambling and sex addiction, they claim.

Restless leg syndrome affects up to 10 per cent of the population, leading to an unpleasant ‘crawling’ sensation in the legs, mostly at night, and an almost irresistible urge to move them.

Dopamine agonists interact with parts of the brain that control movement and have been found to ease restless legs. They are also prescribed for Parkinson’s disease – a neurological condition that affects movement – but there is a considerable downside.

They also affect the parts of the brain that regulate feelings of pleasure and reward, meaning that people can find heightened pleasure from stimulating activities such as shopping, sex and gambling. And this can quickly lead to addiction.

‘It is well known that these drugs cause impulse control disorders such as compulsive gambling and sex addiction in up to one in five Parkinson’s patients,’ says Dr Guy Leschziner, an expert in sleep disorders and neurology.

He adds: ‘The issue is that we don’t have many other options for either condition. The crucial thing is that every patient given a dopamine agonist needs to be informed of the risk.

‘For the people who have had these side-effects and not been warned it can be life-ruining.’

One patient with restless leg syndrome hit by the side-effect told The Mail on Sunday that he developed a serious gambling addiction and lost £100,000.

The married father of two, 54, who asked to be referred to only as Mr Wilson, had never placed a bet before he was prescribed the dopamine agonist ropinirole in 2014. After months of near constant leg spasms, he says he felt ‘relieved’ that the GP offered him a diagnosis of restless leg syndrome and a solution to his sleepless nights.

He was prescribed a low dose of ropinirole but as symptoms persisted, his doctor gradually increased this over two years.

Eventually the symptoms of restless leg syndrome subsided, but that is when his other problems began. ‘I remember seeing an advert on my computer for an online slot machine, which said it offered better odds than the lottery. I thought, well, I do that so why not give it a go.

‘It started small with bets and I was winning a little. But when I started losing, I would chase my losses. That’s when it spiralled and I was betting daily.

‘It really drove a wedge between me and my family. I was incredibly secretive about what was going on but my personality started to change and I was becoming aggressive.’

Over four years on the drug he lost £100,000 betting on online slot machines, across dozens of bookmakers. ‘I took out two loans, maxed credit cards and nearly lost all of our savings. I was betting at every opportunity, even while I was at work,’ he said. ‘It nearly cost me everything.’

Doctors didn’t warn Mr Wilson of the side-effects on multiple occasions, even failing to draw the connection when he went back to his GP ‘pleading’ for help with his gambling habit.

It was only when he told a hospital consultant, during a routine appointment for another issue, that he was struggling with gambling, that he was told his medication could be the cause.

After a long legal battle, the NHS finally admitted full responsibility, and he was awarded £150,000 compensation and damages.

‘It should never have happened, we lost years of our lives we will never get back. We survived and are moving forward in a positive way as a family,’ says Mr Wilson.

In December, Philip Stevens, 66, from Ringwood, Hampshire, won £70,000 compensation after developing a gambling addiction while taking ropinirole for restless leg syndrome.

Impulse control disorder is not the only side-effect. According to a survey by RLS-UK of more than 3,000 people with the condition, 65 per cent who had taken dopamine agonists have switched medications because their restless leg symptoms worsened.

The overwhelming research evidence has led to the American Academy of Sleep Medicine publishing new guidelines in November that told clinicians in the US not to prescribe dopamine agonists and, instead, opt for calcium channel blockers.

Campaigners are calling for an urgent update to the prescription guidelines. ‘These drugs should be used only as end-of-life care, and never be used as the first treatment for patients. We really need to see official guidelines developed for restless leg syndrome,’ says Julie Gould, a trustee of RLS-UK.