LAUSR

STUDY OBJECTIVES Restless Legs Syndrome (RLS) is a sensory-motor neurological disorder. Low dose opioid medications are prescribed for treatment-refractory RLS. We describe baseline and 1-year longitudinal dosing and symptom outcomes for the National RLS Opioid Registry. METHODS Individuals currently taking a prescribed opioid for diagnosed RLS are included in the registry. Information on initial and current opioid dosages, side effects, past and current concomitant RLS treatments, RLS severity, psychiatric history, and opioid abuse risk factors was collected at baseline. Follow-up online surveys were performed at 6 months and 1-year. RESULTS Participants (n=500) are primarily white, elderly, educated, and retired. Half of all subjects are on opioid monotherapy. Nearly 50% of all subjects are taking methadone, and one-quarter are taking oxycodone formulations. The median total daily opioid dose is 30.0 MME. At baseline, three-quarters of registry participants had been taking a prescribed opioid for RLS for more than one year and one-third for more than five years, and had mild-moderate RLS symptoms. At 1-year follow-up, 31.2% increased dose (median=10 MME) and 16.0% decreased dose of their opioid. An MME increase ≥25 was associated with: opioid use for non-RLS pain, <1 year of opioid use, opioid switch to methadone, and discontinuation of non-opioid RLS medications which, combined, accounted for 91.7% of those with 1-year follow-up increases ≥25 MME. CONCLUSIONS In refractory RLS, prescribed opioids are generally used at low doses with good efficacy. Longitudinally over one year, roughly one-third of participants increased their prescribed opioid dose, though generally by small amounts, with larger dose increases accounted for by predictable features.