Treatment with ropinirole is effective in early PD and substantially reduces the risk of dyskinesias. A five-year double-blind study

Design/Methods: This prospective, randomised, double-blind, parallelgroup study compared the long-term efficacy and safety of ropinirole, a non-ergoline D2 dopamine agonist, with L-dopa (ratio 2:, ropinirole: L-dopa) over 5 years in 268 early de nova Parkinson's disease (PD) patients. The study was completed in January 1999. Patients with insufficient therapeutic benefit could supplement double-blind medication with open use of adjunct L-dopa and continue in the study. Efficacy and complications of therapy were assessed using the UPDRS and adverse experience information. Results: Eighty-five (47%) ropinirole patients and 45 (51%) L-dopa patients completed all five years of the study. Of these, 29 (34%) ropinirole patients and 29 (64%) L-dopa patients did so on monotherapy. Although overall, more ropinirole patients 92 (51%) than L-dopa patients 31 (35%) were given adjunct open L-dopa at any point during the five years, this difference should not be regarded as an indication of L-dopa efficacy, as open adjunct L-dopa was rarely added after the emergence of dyskinesias, which were more common in the L-dopa group (see below). In the ropinirole group, the mean doses in patients completing all five years were 16.5 mg (SD 6.6) ropinirole and 427.2 mg (SD 220.8) adjunct open L-dopa. In the L-dopa group, the dose (including adjunct open L-dopa) was 753.3 mg (SD 397.5). The incidences of dyskinesias prior to any adjunct open L-dopa were 5% on ropinirole and 36% on L-dopa (odds ratio, 15.2; 95% CI, 6.2-36.9; P <0.0001 ). The incidences of dyskinesias in the ropinirole and L-dopa groups, regardless of whether adjunct open L-dopa was used or not, were 20% and 46%, respectively (odds ratio, 3.8; 95% CI, 2.1-6.9; P <0.0001 ). At baseline, the mean ADL scores were the same in both groups (ropinirole=8.0 (SD 5.0), L-dopa=8.0 (SD 4.6)) and remained similar to each other at each timepoint during the study. In those patients completing all five years, the mean scores were 9.1 (SD 5.8) in the ropinirole group and 7.2 (SD 5.0) in the L-dopa group. The difference in mean change from baseline was not statistically different. Forty-eight (27%) ropinirole patients and 26 (29%) L-dopa patients withdrew from the study prematurely as a result of adverse experiences. These adverse experiences were typical for dopaminergic agents. Forty-two (23%) ropinirole patients and 14 (16%) L-dopa patients reported CNS adverse experiences, including hallucinations and confusion. This was not statistically different. Conclusion: The result of this large multinational trial conclusively show that patients with early PD are successfully managed on ropinirole alone, or with a low dose of adjunct L-dopa added later, for up to 5 years. Most importantly, the risk of developing dyskinesias was substantially reduced in patients receiving ropinirole, either as monotherapy for the entire study period or in conjunction with a low dose of adjunct L-dopa in the latter part of the study, compared to those treated with L-dopa from the outset.