Efficacy and safety of pramipexole in restless legs syndrome

Objective: To evaluate the efficacy and safety of pramipexole in patients with moderate to severe restless legs syndrome (RLS) Methods: The authors conducted a 12-week, double-blind, randomized, placebo-controlled trial of fixed doses of pramipexole (0.25, 0.50, and 0.75 mg/day). Patients (N = 344) were up-titrated to their randomized dose over 3 weeks. The primary efficacy endpoints were patient ratings of symptom severity on the International RLS Study Group Rating Scale (IRLS) and clinician ratings of improvement on the Clinical Global Impressions-Improvement (CGI-I) scale. Secondary efficacy endpoints included visual analogue ratings of sleep and quality of life (QOL) Results: By both primary measures, pramipexole was superior to placebo. For IRLS, the adjusted mean ( SE) change from baseline to week 12 was -9.3 (1.0) for placebo, -12.8 (1.0) for 0.25 mg/day, -13.8 (1.0) for 0.50 mg/day, and -14.0 (1.0) for 0.75 mg/day (all p < 0.01). Similarly, pramipexole increased the percentage of patients with a CGI-I rating of "very much improved" or "much improved" at the end of the trial (51.2% for placebo and 74.7%, 67.9%, and 72.9% for pramipexole; all p < 0.05). Pramipexole significantly improved ratings of symptom severity, day and night, and also ratings of sleep satisfaction and QOL. Pramipexole was well tolerated: The most frequent adverse events with higher occurrence in the pramipexole group were nausea (19.0% vs 4.7%) and somnolence (10.1% vs 4.7%) Conclusion: As rated by patients and by clinicians, pramipexole was efficacious and safe in reducing the symptoms of restless legs syndrome.