Common Parkinson’s drugs linked to compulsive behaviour

Some of the most common medicines used for treating Parkinson’s disease in the UK could lead patients into compulsive behaviour, it has been warned. Researchers at the Sorbonne University in Paris have found a link between the drugs and an inability to control irresistible urges.

The dopamine agonists are thought to lead some Parkinson’s sufferers to become compulsive gamblers or binge eaters. Other potential side effects that fall under the compulsive behaviour banner include frequent shopping and uncontrollable sexual behaviour.

It is estimated that 127,000 people in the UK are living with Parkinson’s, which causes dopamine in the brain to gradually reduce over time. The chemical is responsible for regulating movement, which is why those with the progressive neurological condition develop tremors.

Levodopa, which converts into dopamine in the brain, and dopamine agonists that activate the dopamine receptors, are both commonly used to treat Parkinson’s. They enable those with the condition, who are mainly elderly, to live a more independent life, but it seems there may be a price to pay for the treatment.

The research followed 411 volunteers for an average of three years to find out about their compulsive urges. All of the subjects had been diagnosed with Parkinson’s, but some of the individuals had taken the drugs and others had not.

Out of those who had taken Parkinson’s medication, 52 per cent struggled with uncontrollable behaviour. This is in stark contrast to the drug-free group, where just 12 per cent of the subjects experienced compulsive urges.

Further findings revealed that the higher the doses of dopamine agonists, the greater the chances were of having impulse control disorders. Pramipexole and ropinirole were the two drugs associated with biggest risk of such side effects.

The scientists also monitored 30 people with impulse control disorders as they came off dopamine agonists. Over time, the compulsive behaviour slowly stopped and just a year after taking the medication, 50 per cent no longer have any issues of this nature.

Dr Jean-Christophe Corvol, study author, said: “Our study suggests that impulse control disorders are even more common than we thought in people who take dopamine agonists. These disorders can lead to serious financial, legal and social and psychological problems.”

It’s understandable that relatives should be concerned if elderly parents or grandparents start to display compulsive behaviour. It can impact on their wellbeing and the way that they interact with others.

Parkinson’s is a serious condition, however, and with no cure yet invented, is something that many people have to learn to live with. Therefore, it is a case of analysing the risks and potential side effects and working out the best care plan for each individual alongside medical professionals.

Scientists are working on a way to stop Parkinson’s progression and there are hundreds of trials taking place to establish the usefulness of drugs. In the meantime, sufferers have to cope with stiffness in the muscles, slow movement, tremors, disturbed sleep, chronic fatigue. All of this means a reduced quality of life.