Methadone for refractory restless legs syndrome

Most cases of restless legs syndrome (RLS) initially respond well to dopaminergic agonists. However, an unknown percentage of patients is intolerant of dopaminergic adverse events, initially or subsequently refractory, or develops limiting augmentation. We administered methadone 5 to 40 mg/day (final dose, 15.6 +/- 7.7) to 29 RLS patients who failed dopaminergics. They were currently taking or had previously tried 5.9 +/- 1.7 (range, 3-9) different medications for RLS and 2.9 +/- 0.8 (range, 2-4) different dopaminergics. Of the 27 patients who met inclusion criteria, 17 have remained on methadone for 23 +/- 12 months (range, 4-44 months) at a dose of 15.5 +/- 7.7 mg/day; 2 dialysis RLS patients died while on methadone, and 8 stopped the treatment (5 for adverse events, 2 for lack of efficacy, and 1 for logistical reasons). All patients who remain on methadone report at least a 75% reduction in symptoms, and none have developed augmentation. Methadone should be considered in RLS patients with an unsatisfactory dopaminergic response. (c) 2004 Movement Disorder Society.