Dopamine agonists in the treatment of early Parkinson's disease: a meta-analysis.

Our objective was to perform a meta-analysis of randomized controlled trials of dopamine agonists (DA) as monotherapy as well as adjunctive therapy for the early treatment of Parkinson's disease (PD). A systematic literature search was conducted through April 2007. Both efficacy and safety endpoints were evaluated. DA monotherapy showed superior efficacy but more frequent adverse events compared to placebo. In addition, DA demonstrated inferior efficacy to levodopa, but was associated with fewer motor complications. However, DAs were associated with a greater incidence of nuisance side effects, such as hallucinations, somnolence and dizziness. The use of DA is an effective treatment option for the treatment of early PD and appears especially useful among PD patients with wearing-off phenomenon or dyskinesias on levodopa; however it may result in more adverse events and higher withdrawal rates.