Efficacy and safety of pramipexole extended-release in Parkinson's disease: a review based on meta-analysis of randomized controlled trials

Background and purpose: We performed a meta-analysis of randomized controlled trials to evaluate the efficacy and safety of pramipexole extended-release (pramipexole ER) versus pramipexole immediate-release (pramipexole IR) or placebo in Parkinson's disease. Methods: We performed a systematic online search for clinical trials for pramipexole ER treatment up to 1 August 2016. We assessed differences in Unified Parkinson's Disease Rating Scale (UPDRS) scores, percentage of 'on' time or 'off' time, withdrawals, adverse events (AEs) and life quality between pramipexole ER and pramipexole IR or placebo. Data analyses were performed by the Cochrane Collaboration's Review Manager 5.3 software. Results: Six randomized controlled trials were included. Compared with placebo, pramipexole ER achieved a significant improvement in the UPDRS Part II + III score [weighted mean difference, -4.81; 95% confidence interval (CI), -6.40 to -3.23], whereas no significant difference was found in the UPDRS Part III + III score between pramipexole ER and pramipexole IR groups (weighted mean difference, -0.26; 95% CI, -1.15 to 0.64). No differences were found in total AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03), drug-related AEs (relative risk, 0.97; 95% CI, 0.92 to 1.03) or the commonly reported AEs between pramipexole ER and pramipexole IR. Conclusions: Pramipexole ER is as safe and effective as pramipexole IR in the treatment of Parkinson's disease.