Abstract Study Objectives Large long-term assessments of opioid effectiveness and dose stability for those with dopamine agonist augmentation of restless legs syndrome (RLS) are lacking. We present 5-year longitudinal findings from the National RLS Opioid Registry. Methods Five-hundred participants taking opioids for RLS were interviewed at baseline about RLS symptoms, opioid medications and doses, sleep and mental health. Participants subsequently completed online surveys every 6 months. Changes from baseline to 5-year follow-up in morphine milligram equivalents (MME), excluding those taking buprenorphine, were evaluated by group-based trajectory modeling. Independent associations with opioid dose changes were determined using multiple logistic regression. Results At 5-years of follow-up, 410 (364 excluding any taking buprenorphine) participants remained for this analysis. Most participants are female (57.1%) and white (98.3%), with an average age of 64.7 (±10.6) and 88.8% had a history of dopamine agonist augmentation. The median daily MME at 5-years was 37.5 (equivalent to methadone 8.0 mg or oxycodone 25.0 mg), an increase of 7.5 MME from baseline. Opioid doses increased from baseline to 5-years in 49.5% of participants and decreased in 20.0% of participants. Group-based trajectory analysis identified four distinct groups: decrease (3.4% of participants; average MME change=-15.7±12.4), no/little change (66.1% of participants; average MME change=1.5±8.0), small increase (23.9% of participants; average MME change=22.0±11.6), and large increase (3.4% of participants; average MME change=49.2±18.7). RLS severity was stable from baseline (13.3±9.6) to 5-years (13.1±9.0) according to the IRLS severity scale. Conclusions Opioid doses in augmented RLS remain largely stable over five years of follow-up. Low-dose opioids provide an effective long-term option for augmented RLS.
Winkelman et al. (Wed,) studied this question.