Subject: Early ropinirole reduces dyskinesias (PD Congress report)
Date: 8/1/1999
Early therapy with ropinirole reduces the later incidence of dyskinesias compared to levodopa, according to a five-year, randomized, double blind study. The study, supported by the manufacturer of ropinirole, Smith-Kline Beecham, has been submitted for publication.
Olivier Rascoll of INSERM at Toulouse, France, led the multi-center study of 268 early PD patients, who had been treated with levodopa for a maximum of six weeks before entering the study. Patients were randomized 2:1 to either ropinirole (up to 24 mg/day) or levodopa (up to 1200 mg/day); either treatment could be supplemented with open-label levodopa as needed to achieve best symptom management. The primary endpoint was the incidence of dyskinesias.
After 5 years, approximately one half of patients remained in the study. Of these, 34% of ropinirole patients remained on monotherapy. At the study's end, the mean dose of ropinirole was 16.5 mg/day as monotherapy, and the mean levodopa dose was 750 mg/day, 250 mg dosed three times daily. Rascoll noted that, although more frequent levodopa dosing may be more common clinically as the disease progresses, the levodopa dosing schedule was maintained at 3X daily to prevent breaking the blind.
After five years, 80% of patients on ropinirole or ropinirole/levodopa remained free of dyskinesias, versus 54% for those on levodopa. No significant differences were seen among groups for wearing off, freezing, or dopaminergic side effects, except hallucinations, which were more common in the ropinirole group. Rascoll concluded, "The risk for developing dyskinesias was substantially less with ropinirole monotherapy or with ropinirole plus levodopa supplementation." During a question period, Rascoll noted that, while there was no evidence to definitively show that other dopamine agonists would have the same effect, there was no reason to think they might not.