February 13, 2014
News Review From Harvard Medical School -- Drug Option May Help Restless Legs
A new study finds that a drug less commonly used for restless legs syndrome may work just as well as the standard treatment. It also may help prevent a common side effect of treatment, the study found. People with restless legs syndrome have a variety of uncomfortable sensations in their legs. They feel an uncontrollable urge to move their legs. This often disturbs sleep. The new study included 720 people with moderate to severe restless legs syndrome. They were randomly divided into groups. The groups received the standard treatment pramipexole (Mirapex), pregabalin (Lyrica) or placebo (fake pills). After 12 weeks of treatment, pregabalin improved symptoms as well as pramipexole. During up to a year of treatment, people taking pregabalin also were less likely to have their symptoms get worse. About 2% had this problem, compared with 8% of those taking pramipexole. The New England Journal of Medicine published the study. HealthDay News wrote about it February 12.
By Robert H. Shmerling, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Restless legs syndrome is a disorder whose name tells you only part of the story.
A restless feeling in the legs -- an overwhelming urge to move or stretch them -- is a key feature. And it's called a syndrome. This means that the condition has a group of characteristic features. Other features include:
- Symptoms that are worse when at rest
- Relief of symptoms (at least temporarily) by moving the legs
- A tendency for symptoms to occur at night
What the name doesn't tell you is how the condition can disrupt daily life. It's not just a leg problem. Because it tends to cause symptoms at night, it may disrupt sleep so profoundly that you can't function as well during the day. Daytime sleepiness may lead to car accidents. The unpleasant experience of restless legs and the fatigue during the day can have a major impact on quality of life.
Several treatments can be effective. For example, many people improve by taking pramipexole (Mirapex), ropinirole (Requip) or related medicines. However, they don't always work well. And side effects are common. One particularly bothersome side effect is called "augmentation." This means that the medicine actually seems to make things worse. This usually occurs after long-term use.
Pramipexole is a "dopamine agonist." It mimics the action of dopamine, a chemical messenger thought to play an important role in restless legs syndrome. Most of the older, first-line treatments act in a similar way. Pregabalin, another drug that is sometimes prescribed, works in a different way. It alters calcium entry into cells.
Should pregabalin (Lyrica) be a first choice for treatment instead of pramipexole or another dopamine agonist? A new study suggests the answer may be yes.
The study included more than 700 people with restless legs syndrome. Researchers compared pregabalin with two doses of pramipexole and with placebo. Here's what they found:
- Those receiving pregabalin did better in the first 3 months than people taking a placebo. About 71% reported a positive response, compared with 47% in the placebo group.
- During the one-year course of the study, improvement was similar for those taking pregabalin versus the higher dose of pramipexole. But pregabalin was more effective than the lower dose of pramipexole.
- Worsening of symptoms (augmentation) was less frequent with pregabalin treatment than with pramipexole.
Certain side effects (including nausea and headache) were less common with pregabalin treatment than with pramipexole. Others were more common with pregabalin. They included weight gain, drowsiness and thoughts of suicide.
This study suggests that pregabalin is an effective medicine for restless legs syndrome and that it causes less augmentation. These findings could increase its use in treating this condition.
What Changes Can I Make Now?
If you have symptoms of restless legs syndrome, see your doctor. If you are diagnosed with this condition, you can take several steps to reduce symptoms even before considering a prescription medicine. These include:
- Massaging the legs
- Applying heat to the leg muscles
- Taking an iron supplement (for people with iron deficiency, as determined by a simple blood test)
Avoiding drugs that can worsen symptoms, such as:
- Some antidepressants and antihistamines
In addition to dopamine agonists and pregabalin, several other medicines are used to treat restless legs syndrome. They include:
- Benzodiazepines (such as clonazepam)
- Tramadol or related pain relievers
- Gabapentin (Neurontin)
There is no single best choice. Each person's combination of symptoms, other medicines and other medical problems will affect the choice of treatments. It's important to have regular medical follow-up so that symptoms and medicines can be closely monitored.
What Can I Expect Looking to the Future?
Based on this latest research, treatment of restless legs syndrome with pregabalin could become more common. It's helpful that pregabalin is not a new drug. It is already approved for other conditions. So we know what to expect in terms of common side effects. And generic versions should be available in the next several years, which will lower its cost. Future research should provide more guidance regarding the ideal dose of pregabalin (and other medicines) for restless legs syndrome.
For a condition that affects up to 4% of the population, you don't hear much about restless legs syndrome. That could change in the future, especially as more research findings are reported. I hope that we will soon learn the cause (or causes), which should lead to better treatments.