Systematic evaluation of augmentation during treatment with ropinirole in restless legs syndrome (Willis-Ekbom disease): results from a prospective, multicenter study over 66 weeks.

ABSTRACT

The purpose of this study was to evaluate the incidence of augmentation over 66 weeks of treatment with ropinirole in patients with primary restless legs syndrome (RLS). Augmentation is the main complication of long-term dopaminergic treatment of RLS. Despite widespread use of ropinirole in RLS, no studies have prospectively and systematically assessed the incidence of augmentation with its use. The study consisted of 26 weeks of double-blind flexible-dose treatment with ropinirole or placebo, followed by 40 weeks of open-label ropinirole treatment.. Patients had no previous history of augmentation. Potential cases of augmentation were identified with the Structured Interview for the Diagnosis of Augmentation and the Augmentation Severity Rating Scale and through reporting of adverse events. Cases were blindly evaluated by an expert panel using the NIH diagnostic criteria for augmentation. Four hundred and four patients participated in the double-blind study and 269 in the open-label phase, with a discontinuation rate of 42%. IRLS baseline scores improved at the end of the double-blind (DB) phase (mean ± SE) by -15.9 ± 0.76 for ropinirole, by -13.4 ± 0.77 for placebo (P < .05) and by -20.4 ± 0.55 during the open-label phase. The incidence rates of augmentation were 3.5% for ropinirole and <1% for placebo during the DB phase and 3% during the open-label phase. Clinically significant augmentation occurred in 3%, <1%, and 2%, respectively. Discontinuation of treatment occurred in 50% of all patients (7 of 14) with augmentation. The incidence of augmentation was 3.1% higher with ropinirole than with placebo. New patients with first episodes of augmentation continued to cumulate at a stable rate over the duration of this study.