Getting the Right Treatment: Understanding the Risks of Impulse-Control Disorders
Introduction
Getting a headache and feeling sick are common side-effects for many medicines. Indulging in risky sexual behaviour or pathological gambling – not so common. But a BBC investigation has highlighted that some drug treatments for restless leg syndrome and Parkinson’s disease can lead to such risky behaviour.
Restless Legs Syndrome and Parkinson’s Disease: Understanding the Conditions
Over 150,000 people in the UK live with Parkinson’s – a degenerative condition that affects the brain. The main part of their brain that is damaged is the area that produces dopamine, a chemical messenger that regulates movement. Less dopamine in the brain can lead to symptoms such as tremors, muscle stiffness, slow movements, and problems with balance.
Another movement disorder is restless legs syndrome (RLS), which affects between 5% and 10% of people in the UK, US, and Europe. Twice as many women as men have RLS among those aged over 35.
Dopamine-Receptor Agonists: The Medications Behind the Problem
One of the main treatments for movement disorders is a group of drugs called dopamine-receptor agonists, which include cabergoline, ropinirole, bromocriptine, and pramipexole. Dopamine-receptor agonists increase the levels of dopamine in the brain and help regulate movement.
The Link Between Dopamine-Receptor Agonists and Impulse-Control Disorders
Dopamine is known as the "happy" hormone because it is part of the brain’s reward system. When people do something fun or pleasurable, dopamine is released in their brain. But using dopamine-receptor agonist drugs can elevate these feelings, leading to impulsive behavior.
Case Studies: Impulse-Control Disorders and Dopamine-Receptor Agonists
Previous reported cases include a 53-year-old woman taking ropinirole and exhibiting impulsive behavior such as accessing internet pornography, using sex chat rooms, meeting strangers for sexual intercourse, and compulsive shopping. Another case highlighted a 32-year-old man who, after taking ropinirole, started binge eating and gambling compulsively, such that he lost his life savings.
The Incidence of Impulse-Control Disorders: A Growing Concern
Between 6% and 17% of people with RLS who take dopamine agonists develop some form of impulse-control disorder, while up to 20% of people living with Parkinson’s may experience impulse control disorders. However, the true figures may be even higher, as many patients may not associate changes in behavior with their medication, or may be too embarrassed to report it.
Lawsuits and Legal Actions
There have been several individual and class-action lawsuits against pharmaceutical companies, including GlaxoSmithKline and Pfizer, which produce ReQuip and Cabaser, respectively. Patients taking action against these companies claimed they were unaware of these impulsive behavior side-effects.
Conclusion
It is now clearer in the patient information leaflets given with all prescribed medication for movement disorders that impulsive behavior can occur in some patients. If you experience any impulsive behaviors with these medicines, speak to your doctor or pharmacist immediately.
FAQs
- What is restless legs syndrome (RLS)?
Restless legs syndrome is a condition that causes an uncontrollable urge to move the legs, often accompanied by a crawling, creeping, or tingling sensation. - What is Parkinson’s disease?
Parkinson’s disease is a degenerative condition that affects the brain, leading to symptoms such as tremors, muscle stiffness, slow movements, and problems with balance. - What are dopamine-receptor agonists?
Dopamine-receptor agonists are a group of medications that increase the levels of dopamine in the brain and help regulate movement. - What are the risks associated with dopamine-receptor agonists?
The risks associated with dopamine-receptor agonists include headaches, feeling sick, sleepiness, and impulsive behavior, including risky sexual behavior, pathological gambling, compulsive shopping, and binge eating.
