Opioids have been used for hundreds of years to treat restless leg syndrome (RLS), but there is currently a registry to understand the long-term effectiveness of opioids to treat RLS , said John Winkelman, MD, PhD, medical director, sleep disorders clinical research program, Massachusetts General Hospital.
At SLEEP 2022, John Winkelman, MD, PhD, medical director, sleep disorders clinical research program, Massachusetts General Hospital, explained how opioids have been used to treat restless leg syndrome (RLS) and how the National RLS Opioid Registry is evaluating their long-term affects.
How have opioids been proven to help manage severe RLS?
Opioids have been used for hundreds of years to treat restless leg syndrome. They were the first treatment for restless legs. In those days, there was laudanum, which is opium. In the modern era, there was a small study with oxycodone 30 years ago, which demonstrated efficacy for restless leg syndrome. More recently, about 10 years ago, there was a large, double-blind, placebo-controlled trial with oxycodone extended release with naloxone—that combination—which demonstrated efficacy in the controlled study for 12 weeks, and then in the open label extension for a year for treatment of RLS. These are effective medications for the treatment of RLS.
What are some uncertainties surrounding the use of opioids for RLS?
Opioids are medications with a lot of good effects and a number of concerning short-term and long-term potential side effects. So, patients for whom physicians may be prescribing opioids should be carefully screened prior to initiating one of these medications. Similarly, they need to be carefully followed up while [physicians] are prescribing these medications for them. In Massachusetts, and at Mass General Hospital where I work, I am required to meet with them every 4 months, which is fine with me because I like seeing my patients, and I also want to make sure that the medication continues to be effective and well-tolerated.
The uncertainties are: who are the optimal patients for the use of opioids in RLS? There is some uncertainty about long-term tolerability and dose stability with these medications. We are trying to address that with the National RLS Opioid Registry that I started about 5 years ago. We have 500 patients throughout the United States who I'm not following—we give no medical advice—but we survey them every 6 months. We assess the efficacy of the medications for the RLS, the dose of the opioid side effects, and a variety of other end points, to see whether these medications can be trusted to work long-term, because we know that the current medication class that's being most commonly prescribed, the dopamine agonists, cannot be trusted to treat RLS long-term. They lose efficacy and they make the RLS worse. Short-term studies for a long-term condition are a mistake. We have this registry to do long-term monitoring of these patients, 500 of them, on opioids to confirm—what my experience has been—that they continue to be efficacious at stable doses.