Nonergot dopamine-receptor agonists for treating Parkinson’s disease – a network meta-analysis

OBJECTIVE To compare the efficacy of the three nonergot dopamine-receptor agonists (DAs) pramipexole, ropinirole, and rotigotine for the treatment of early and advanced Parkinson's disease (PD). MATERIALS AND METHODS Bayesian network meta-analyses were performed separately for early and advanced PD, and at time points 11-16 and 24-28 weeks. Outcomes for early PD included improvement on the Unified Parkinson's Disease Rating Scale (UPDRS) activities in daily life (UPDRS-II), motor function (UPDRS-III), and their subtotal (UPDRS-II + III). Outcomes for advanced PD also included daily "off time" (hours), but not UPDRS-II + III. RESULTS Totals of 23 and 24 trials informed early and advanced PD analyses. For early PD UPDRS-II at 11-16 weeks, pramipexole and rotigotine were statistically significantly superior to placebo, but ropinirole was not. For UPDRS-III and UPDRS-II + III, all DAs were statistically significantly better than placebo and exhibited similar improvements. At 24-28 weeks, results were also statistically significant for all DAs versus placebo, and the magnitudes of improvements were similar for pramipexole, ropinirole and rotigotine. Advanced PD improvements on UPDRS-II, UPRDS-III, and off time were statistically significant for pramipexole, ropinirole, and rotigotine versus placebo. At 11-16 weeks, rotigotine yielded slightly smaller effects than ropinirole and pramipexole, but credible intervals on differences were wide. For off time, results were near identical. At 24-28 weeks, results were similar for all three outcomes. Ropinirole yielded a slightly higher improvement on UPDRS-III, but a slightly smaller improvement in off time. CONCLUSION Our analyses suggest that pramipexole, ropinirole, and rotigotine exhibit similar efficacy in the treatment of early and advanced PD.