Restless Legs Syndrome (RLS) is a sensory-motor neurological disorder characterized by an irresistible urge to move the legs. Although dopamine agonists and alpha-2-delta calcium channel ligands are effective treatments for this disorder, low dose opioid medications are prescribed for patients with treatment-refractory RLS. The RLS National Opioid Registry is a longitudinal observational study that will provide important information about long-term symptom control, dose escalation and complications in patients using prescribed opioids for RLS. Baseline interviews and recurring 6-month surveys on REDCap collect data on opioid type and dose, side effects, psychiatric symptoms and RLS severity.

At baseline assessment of the 500 enrolled participants, nearly half were taking methadone, and roughly one-quarter were taking oxycodone formulations. The prescribed opioids were generally used at low doses with good efficacy. At 1-year follow-up, 98% remained enrolled and the majority remained on the same opioid dose. Just under a third of participants increased opioid dose, and about 15 percent decreased their dose. Larger dose increases were associated with a number of predictable factors: use of opioid medications for pain in addition to RLS, discontinuation of other RLS medications since baseline assessment, and under 1 year of opioid use at baseline. Continued longitudinal data will grow knowledge on treatment efficacy and tolerability of opioids for RLS which will better inform clinical decisions.