From Bench to Bedside: An Overview of Rotigotine for the Treatment of Restless Legs Syndrome

BackgroundRestless legs syndrome (RLS) is a common chronic neurologic disorder. Symptoms are most prevalent during the evening and at night, although daytime symptoms may emerge as the disease progresses. Dopamine agonists are currently considered first-line therapy for moderate to severe idiopathic RLS. Most dopamine agonists have short half-lives and are administered in the evening, shortly before the onset of RLS symptoms. Rotigotine is a non-ergot dopamine receptor agonist that has been specifically developed as a transdermal patch to provide continuous drug delivery over a 24-hour period.ObjectiveThis review details the development of rotigotine, from the preclinical studies that established its pharmacokinetic profile to large-scale clinical trials in patients with RLS. Placebo-controlled trials that demonstrated the efficacy and tolerability of rotigotine are discussed, in addition to open-label studies that investigated long-term therapy.MethodsStudies were identified by a PubMed search using the key word rotigotine in conjunction with restless legs syndrome and by reviewing reference lists of retrieved publications. All clinical trials of rotigotine in RLS published before September 2013 were included.ResultsPreclinical studies have established activity of rotigotine as a dopamine receptor agonist, and pharmacokinetic data have shown that transdermal delivery maintains stable plasma levels over 24 hours. Rotigotine has demonstrated efficacy in improving moderate to severe RLS symptoms in randomized, placebo-controlled trials, based on scores on the International RLS Study Group rating scale, the RLS-6 scale, and the Clinical Global Impression-Severity subscale. Results of an open-label extension study suggest that efficacy may be maintained for up to 5 years. A polysomnographic study demonstrated an improvement in periodic limb movement index with rotigotine, and subjective assessments have suggested beneficial effects in terms of amelioration of sleep disturbances. Premature discontinuations from rotigotine treatment have ranged from 8% to 38% in studies of 6 weeks to 12 months in duration; 57% of patients discontinued prematurely during a 5-year study. In each trial, adverse events were typical of dopaminergic stimulation and use of a transdermal patch. The most common adverse events were application-site reactions, with a reported prevalence ranging from 17% (1-month sleep laboratory trial) to 58% (5-year open-label extension study). Clinically significant augmentation was recorded in 39 of 295 patients (13%) receiving rotigotine during the 5-year study, of whom 15 (5%) were receiving a dose within the US Food and Drug Administration-approved range of 1 to 3 mg/24 h.ConclusionsFindings from clinical studies have suggested that rotigotine is efficacious in improving RLS symptoms and is generally well-tolerated. The risk of developing clinically significant augmentation appears to be low. As such, rotigotine represents an important addition for RLS treatment.