Pharmacologic therapy for primary restless legs syndrome: a systematic review and meta-analysis.

IMPORTANCE Restless legs syndrome (RLS) is a neurological disorder characterized by unpleasant sensations in the legs and a distressing, irresistible urge to move them. We conducted a systematic review to evaluate efficacy, safety, and comparative effectiveness of pharmacologic treatments for primary RLS. EVIDENCE ACQUISITION We included randomized controlled trials (RCTs), published in English, reporting efficacy outcomes and harms of pharmacologic treatments for primary RLS of at least 4 weeks' duration. MEDLINE and other databases were searched through June 2012. Reviewers extracted outcomes and adverse events and rated the strength of evidence. RESULTS We identified 29 eligible RCTs. We found high-strength evidence that the proportion of patients who had a clinically important response (International Restless Legs Syndrome [IRLS] responders), defined as a 50% or greater reduction from baseline in mean IRLS symptom scale scores, was greater with dopamine agonist therapy compared with placebo (61% vs 41%) (risk ratio, 1.60 [95% CI, 1.38-1.86]; 7 trials). Dopamine agonists also improved patient-reported sleep scale scores and quality-of-life measures. High-strength evidence demonstrated that calcium channel alpha-2-delta ligands increased the proportion of IRLS responders compared with placebo (61% vs 37%) (risk ratio, 1.66 [95% CI, 1.33-2.09]; 3 trials). Adverse events associated with dopamine agonists included nausea, vomiting, and somnolence. Alpha-2-delta ligands adverse events included somnolence and unsteadiness or dizziness. CONCLUSIONS AND RELEVANCE On the basis of short-term RCTs that enrolled highly selected populations with long-term high-moderate to very severe symptoms, dopamine agonists and calcium channel alpha-2-delta ligands reduced RLS symptoms and improved sleep outcomes and disease-specific quality of life. Adverse effects and treatment withdrawals due to adverse effects were common.