Compulsive Gambling a possible side-effect of Restless Leg Syndrome drugs

Restless Legs Syndrome is a neurological disorder, in spite of what you might think from the ridiculous ads on television. RLS is a syndrome where the individual has weird sensations in their legs while they are trying to relax. These sensations can be just unpleasant, or they can be quite painful. The result is that the individual has trouble sleeping -- leading to a marked reduction in their quality of life and ability to function.

RLS is treated with drugs similar to Parkinson's drugs -- drugs that function as dopamine agonists. It is known that a rare side effect of Parkinson's drugs is compulsive gambling. This is likely because dopamine does a lot of different things in the brain. One of them is regulating movement, but another has to do with the brain's perception of reward. People with too much dopamine in some parts of their brains get a perverse sense of reward, hence the problems with gambling.

A Mayo Clinic study has now identified a suspiciously large number of patients with RLS who have developed compulsive gambling, even though individuals with RLS are often on much lower doses of the drugs involved.

Background to RLS

When I mean ridiculous ads, I mean ones like these...

I guess there really aren't normal drug ads nowadays, but there is no way to watch this and not wonder whether the drug company made this condition up. Well they didn't. It is actually real.

Here is some background about RLS:

Restless legs syndrome (RLS) is a neurological disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move when at rest in an effort to relieve these feelings. RLS sensations are often described by people as burning, creeping, tugging, or like insects crawling inside the legs. Often called paresthesias (abnormal sensations) or dysesthesias (unpleasant abnormal sensations), the sensations range in severity from uncomfortable to irritating to painful.

The most distinctive or unusual aspect of the condition is that lying down and trying to relax activates the symptoms. As a result, most people with RLS have difficulty falling asleep and staying asleep. Left untreated, the condition causes exhaustion and daytime fatigue. Many people with RLS report that their job, personal relations, and activities of daily living are strongly affected as a result of their exhaustion. They are often unable to concentrate, have impaired memory, or fail to accomplish daily tasks.

Some researchers estimate that RLS affects as many as 12 million Americans. However, others estimate a much higher occurrence because RLS is thought to be underdiagnosed and, in some cases, misdiagnosed. Some people with RLS will not seek medical attention, believing that they will not be taken seriously, that their symptoms are too mild, or that their condition is not treatable. Some physicians wrongly attribute the symptoms to nervousness, insomnia, stress, arthritis, muscle cramps, or aging.

RLS occurs in both genders, although the incidence may be slightly higher in women. Although the syndrome may begin at any age, even as early as infancy, most patients who are severely affected are middle-aged or older. In addition, the severity of the disorder appears to increase with age. Older patients experience symptoms more frequently and for longer periods of time.

More than 80 percent of people with RLS also experience a more common condition known as periodic limb movement disorder (PLMD). PLMD is characterized by involuntary leg twitching or jerking movements during sleep that typically occur every 10 to 60 seconds, sometimes throughout the night. The symptoms cause repeated awakening and severely disrupted sleep. Unlike RLS, the movements caused by PLMD are involuntary-people have no control over them. Although many patients with RLS also develop PLMD, most people with PLMD do not experience RLS. Like RLS, the cause of PLMD is unknown.

The Mayo Study

Researchers at Mayo identified 3 patients who developed compulsive gambling after being treated with either pramipexole or ropinirole -- two drugs used to treat RLS. (Ropinirole is the drug advertised above. It's trade name is Requip.) Here is the press release:

Compulsive gambling with extreme losses -- in two cases, greater than $100,000 -- by people without a prior history of gambling problems has been linked to a class of drugs commonly used to treat the neurological disorder restless legs syndrome (RLS). A new Mayo Clinic study is the first to describe this compulsive gambling in RLS patients who are being treated with medications that stimulate dopamine receptors in the brain. The Mayo Clinic report appeared in the Jan. 23 issue of Neurology (http://www.neurology.org).

...

This preliminary Mayo Clinic report is the first to link pathologic gambling to use of dopamine agonists in a disease other than Parkinson. It is based on the experience of three patients who have RLS. Their gambling problems were discovered during their medical evaluations at the Mayo Clinic Sleep Disorders Center. Although three patients is a small sample and larger studies are needed to validate these observations, the Mayo Clinic authors believe that the possible link between dopamine agonists and pathologic gambling behavior should be brought to physicians' attention immediately due to the social and financial consequences resulting from the behavior.

The study was published in the journal Neurology.

I would just emphasize that 3 patients is not a lot of people, but it is when you are talking about a rare side effect. What has to happen now is that there needs to be a larger trial to determine whether compulsive gambling is indeed statistically more likely with these drugs at these doses. I don't know necessarily whether that study will show an effect, but if I were prescribing RLS drugs I would make sure to warn my patients about this possible side effect.

Better to get on top of it before it ruins someone's life.