Title : Efficacy of rasagiline as an adjunct therapy in chronically treated Parkinson’s disease: A meta analysis
Abstract:
Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the basal ganglia, leading to disabling motor and non-motor symptoms. Long-term dopaminergic therapy, including levodopa and dopamine agonists, is frequently complicated by motor fluctuations such as wearing-off phenomena and dyskinesias. Rasagiline, an irreversible monoamine oxidase-B (MAO-B) inhibitor, enhances central dopaminergic activity by preventing dopamine degradation and is commonly used as adjunctive therapy. Although several randomized controlled trials have evaluated its benefits, the overall magnitude of clinical improvement remains variably reported. This meta-analysis was conducted to systematically assess the efficacy of adjunct rasagiline compared with placebo in patients with Parkinson’s disease receiving chronic dopaminergic therapy.
Objective: To evaluate the efficacy of rasagiline as an adjunct therapy in reducing motor fluctuations and improving functional outcomes in patients with Parkinson’s disease undergoing long-term dopaminergic treatment.
Methods: A systematic literature search was performed according to PRISMA 2009 guidelines to identify randomized controlled trials comparing rasagiline with placebo in Parkinson’s disease patients receiving long-term dopaminergic therapy. Only head-to-head randomized controlled trials were included, while observational studies, unpublished studies, and trials not meeting PRISMA criteria were excluded. Data extraction was performed systematically and statistical analysis was conducted using RevMan version 5.3. The primary outcomes included changes in the Unified Parkinson’s Disease Rating Scale (UPDRS), particularly motor-ON and activities of daily living during OFF periods (ADL-OFF). Standardized mean differences were calculated using both fixed-effect and random-effects models. Heterogeneity across studies was assessed using the I² statistic, and statistical significance was defined as p < 0.05.
Results: Six randomized controlled trials comprising 886 patients were included in the analysis. Adjunct rasagiline demonstrated a significant improvement in motor function compared with placebo. For UPDRS motor-ON scores, the fixed-effect model showed a significant benefit (CI 0.586–0.781; p<0.001), while the random-effects model also demonstrated significant improvement (CI 0.260–1.173; p=0.002). Similarly, rasagiline significantly improved activities of daily living during OFF periods. The fixed-effect model demonstrated a CI of 0.854–1.061 (p<0.001), while the random-effects model showed a CI of 0.106–1.755 (p=0.027). Overall heterogeneity between studies was acceptable.
Conclusion: Adjunct rasagiline at a dose of 1 mg/day significantly improves motor function and daily functional performance in patients with Parkinson’s disease experiencing motor fluctuations during long-term dopaminergic therapy. These findings support the use of rasagiline as an effective adjunctive therapy for optimizing symptomatic control and improving quality of life in patients with Parkinson’s disease.
Keywords: Rasagiline , Parkinson disease , UPDRS , motor on and off , Metaanalysis
