Pramipexole in restless legs syndrome: an evidence-based review of its effectiveness on clinical outcomes

INTRODUCTION Restless legs syndrome (RLS) affects 5-15% of adults, but is often unrecognized and consequently misdiagnosed. The International Restless Legs Scale (IRLS) has been developed and validated to assess the severity of RLS. Currently, the most common treatment for RLS is levodopa, but this may lead to augmentation of symptoms. Pramipexole has been developed as an alternative treatment for patients diagnosed with RLS. AIMS The objective of this article is to review the evidence of the effectiveness of pramipexole for the clinical management of patients with RLS. EVIDENCE REVIEW There is clear evidence that pramipexole reduces the leg movements associated with RLS, as measured by improvements in both the IRLS and the Clinical Global Impression (CGI) score. There is also moderate evidence that the drug improves sleep quality. Pramipexole clearly improves the anxiety and depression often associated with RLS. Augmentation may be associated with pramipexole treatment, but the evidence is contradictory and augmentation may be more associated with patients pretreated with levodopa or with patients with primary RLS rather than those with secondary RLS. Pramipexole therapy appears to be well tolerated, with only mild-to-moderate adverse events reported. OUTCOMES SUMMARY Pramipexole reduces leg movements in RLS, and is well tolerated. Further investigation is required to confirm the preliminary evidence that pramipexole restores normal sleep architecture and restores a normal quality of life in patients with RLS. Health economic studies would be valuable in demonstrating the true impact of pramipexole on the social burden of RLS.