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

Study objectives: To define the effective dose of cabergoline and to evalua te the tolerability and efficacy of cabergoline in patients with restless l egs 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 stud y 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 si gnificant 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 (1 0.4+/-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 v s, 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 beca me free of RLS symptoms. Conclusion: Cabergoline is effective and well tolerated in restless legs sy ndrome especially in patients with severe RLS and those who developed augme ntation under levodopa therapy.