We report the results of a randomized, double-blind, placebo-controlled, 16-week study to evaluate the efficacy and safety of
ropinirole, 0.75 to 15.0 mg/day, as an adjunct to
levodopa. A total of 243 patients were randomly assigned into placebo or
ropinirole groups. The mean (standard deviation) dose of
ropinirole at endpoint was 7.12 (2.88) mg/day. The primary endpoint-the mean reduction in the Unified Parkinson's Disease Rating Scale (UPDRS) total motor score-was significantly greater for the
ropinirole group than the placebo group (-9.5 vs. -4.5, P = 0.00001). The mean reduction in the UPDRS total
activities of daily living (
ADL) score was also significantly greater for
ropinirole than for placebo (-2.7 vs. -1.0, P = 0.0002). The percentage of patients showing at least a 20% reduction in the percentage of time spent "off" was significantly greater for the
ropinirole group than for the placebo group (58.7% vs. 38.6%, P = 0.030). A total of 84.3 and 65.6% of the patients experienced adverse events while receiving
ropinirole or placebo, respectively. The results showed that
ropinirole was more effective than placebo in improving motor function and
ADL when used as an adjunct to
levodopa in patients with advanced
Parkinson's disease.