Treatment of idiopathic restless legs syndrome (RLS) with the D2-agonist cabergoline - An open clinical trial

Abstract

Study objectives: To define the effective dose of cabergoline and to evaluate the tolerability and efficacy of cabergoline in patients with restless legs syndrome (RLS). Design: Treatment of idiopathic RLS patients with cabergoline in a 12-week open label trial. Patients on levodopa therapy were allowed to either stop levodopa prior to study entry or to continue, taper or discontinue levodopa during the study. Efficacy parameters were assessed by polysomnography and subjective ratings at baseline and at week 12. Primary efficacy parameters were the number of PLM and total sleep time. Setting: Dept. of Neurology, Sleep Disorders Center Patients: Nine patients with moderate to severe RLS (age 38.1 to 64.3 years, mean 54.1 years) who had experienced insufficient benefit under levodopa therapy and/or in part developed daytime augmentation participated. At study entry five patients were still under levodopa therapy (400-800 mg). Interventions: Up-titration of cabergoline (single evening dose) until RLS symptoms clearly improved. Initial comedication with domperidone 20 mg t.i.d. Measurements and Results: At the endpoint all patients were on cabergoline monotherapy (mean dosage 2.1 mg, range 1 to 4 mg). Domperidone was stopped in all patients due to good tolerability. Polysomnographic data showed a significant reduction of the number of periodic leg movements (PLM) (195.8±109.1 (baseline) vs. 26.4±40.2 (12 weeks cabergoline monotherapy; p = 0.002), PLM arousals (51.7±42.3 vs. 6.4±11.2; p = 0.017) and PLM awakenings (10.4±7.8 vs. 1.0±1.7; p = 0.001). Total sleep time was prolonged (302.7±50.7 vs. 379.4±59.8 min; p = 0.018), sleep latency shortened (42.4±49.1 vs. 16.3±22.8 min; p = 0.214) and sleep efficiency increased (63.1±10.5 vs. 79.1±12.5%; p = 0.017). All patients reported a impressive relief or became free of RLS symptoms. Conclusion: Cabergoline is effective and well tolerated in restless legs syndrome especially in patients with severe RLS and those who developed augmentation under levodopa therapy.