An overview of levodopa in the management of restless legs syndrome in a dialysis population: pharmacokinetics, clinical trials, and complications of therapy

OBJECTIVE: To review published literature investigating the efficacy and safety of levodopa in the management of restless legs syndrome (RLS), with emphasis on the hemodialysis population. DATA SOURCES: An English-language literature search using MEDLINE was conducted from 1966 to 1997 (key terms: restless legs syndrome, levodopa, hemodialysis). The bibliographies of all identified published articles were reviewed and cross-referenced to ensure that all possible references were identified. STUDY SELECTION AND DATA EXTRACTION: All identified human studies investigating the use of levodopa for the management of RLS in uremic and nonuremic patients were analyzed. RESULTS: The prevalence of RLS is 20-40% in patients with endstage renal disease (ESRD) and approximately 5% in the general population. Although the benefits of levodopa/(carbidopa/benserazide) in reducing the signs and symptoms of RLS are documented in nonuremic patients, evidence in patients with ESRD is less readily available. Three small (< 30 subjects) clinical trials in uremic patients provide preliminary evidence for the usefulness of levodopa/(carbidopa/benserazide) in this population. CONCLUSIONS: In general, the small amount of published literature supports the empirical use of levodopa/carbidopa as a safe and effective therapy to manage the distressing symptoms of RLS in a hemodialysis population. We also report personal observations over a 4-year period in our hemodialysis unit that support levodopa as an effective first-line therapy. We have averted suicidal ideation in two patients and frequently modified symptoms of severe sleep deprivation. The dose of levodopa/carbidopa must be individually titrated to each patient's symptomatology, and morning rebound and afternoon augmentation should be monitored.