Clinical efficacy of ropinirole for restless legs syndrome is not affected by age at symptom onset

Abstract

Objective To determine whether clinical response to the dopamine agonist, ropinirole, in the treatment of primary restless legs syndrome (RLS), depends upon the age-at-onset of RLS symptoms. Methods Pooled data from four 12-week, randomized, double-blind, placebo-controlled studies of ropinirole in patients with moderate-to-severe primary RLS were analyzed post hoc. The relationship between age-at-onset and response to treatment, based on change from the baseline International Restless Legs Syndrome Study Group (IRLSSG) rating scale (the International Restless Legs Scale [IRLS]) total score and the proportion of responders (rated ‘much’/‘very much’ improved) on the Clinical Global Impression–Improvement (CGI-I) scale, was explored. Results The range of age-at-onset of RLS symptoms was 2–75 years. No relationship was observed between the age-at-onset of RLS symptoms and baseline IRLS total score (correlation r = −0.06), and between dose administered at Week 12 last observation carried forward (LOCF) and age-at-onset ( r = −0.04). The age-at-onset by treatment interaction was non-significant ( P = 0.952 for the IRLS and P = 0.716 for the CGI-I scale), indicating there was no significant relationship between age-at-onset and the magnitude of ropinirole treatment effect. Conclusions These data suggest that ropinirole provides effective relief of symptoms, regardless of age at RLS symptom onset.