Ropinirole as an Adjunct to Levodopa in the Treatment of Parkinson's Disease

ABSTRACT

BACKGROUND: Ropinirole is a non-ergoline D2 agonist which has a highly selective affinity to D2 receptor. The aim of this study was to evaluate the efficacy and safety of ropinirole in the treatment of Parkinson's disease (PD). METHODS: Seventy-six cases with PD (Hoehn and Yahr stage II to IV) were included in this trial. Each patient was randomly allocated to receive either ropinirole (n=37) or bromocriptine (n=39) over a 16-week period. All subjects were not optimally controlled on levodopa due to motor fluctuations. The response rate was defined as the percentage of patients who had at least 20% reduction of levodopa doses. The clinical status was also assessed using the Unified Parkinson's Disease Rating Scale (UPDRS), Clinical Global Impression (CGI), and reduction of off durations. RESULTS: The end-point analysis, on an intention-to-treat basis, revealed significantly higher response rate in the ropinirole group compared with the bromocriptine group (odds ratio 2.995, 95% C.I. (1.157, 7.751)). A statistically significant improvement in CGI was also observed in the ropinirole group (p=0.046). The mean off duration was significantly reduced in the ropinirole group (p=0.0001). Other parameters using the UPDRS motor score or off duration did not show significant differences between the two groups. The overall incidence of adverse effects was not significantly different between the two groups. The most common side effects were dizziness, dyskinesia, and nausea/vomiting. No subjects were withdrawn from the study due to side effects. CONCLUSION: Ropinirole is a safe and well-tolerated drug and provides superior overall efficacy compared with bromocriptine as an adjunct to levodopa. (J Korean Neurol Assoc 19(2)102~109, 2001)