Table 1. Characteristics of the studies included in the meta-analysis.
| Trial | Design | Dosage | Follow up | Enrolment | Participants | Outcomes | Safety |
|---|---|---|---|---|---|---|---|
| Verhagen Metman 1998 | CO | 350 ± 15 mg/day | 6 weeks | 18 | PD patients with peak-dose dyskinesias, H&Y stages 3.5 ± 0.2 | UPDRS IV AIMs | AEs |
| Luginger 2000 | CO | 300 mg/day | 2 weeks | 11 | PD patients with peak-dose dyskinesias, H&Y stages 2.8 ±1.2 | UPDRS III, IV Marconi DRS | AEs |
| Snow 2000 | CO | 100–200 mg/day | 3 weeks | 24 | PD patients with dyskinesias, H&Y stages (-) | UPDRS III, IV Goetz DRS | AEs |
| Del Dotto 2001 | P | 200 mg IV | 3 hours | 9 | PD patients with peak-dose dyskinesias, H&Y stages 3.0 ± 0.5 | UPDRS III AIMs | AEs |
| Thomas 2004 | P | 300 mg/day | 15 days | 40 | PD patients with peak-dose or biphasic dyskinesias, H&Y stages 2.6 ± 0.2 | UPDRS III, IV Goetz DRS | AEs |
| Silva-Junior 2005 | P | 100–200 mg/day | 3 weeks | 18 | PD patients with peak-dose dyskinesias, H&Y stages 2.5 ± 0.5 | UPDRS III, IV CDRS | AEs |
| Wolf 2010 | P | 100 mg/day | 3 weeks | 32 | PD patients with peak-dose dyskinesias, H&Y stages (−) | UPDRS III, IV | AEs |
| Sawada 2010 | CO | 300 mg/day | 27 days | 35 | PD patients with peak-dose dyskinesias, H&Y stages (−) | UPDRS III, IV RDRS | AEs |
| Goetz 2013 | P | 300 mg/day | 8 weeks | 68 | PD patients with peak-dose dyskinesias, H&Y stages 2 | UDysRS | AEs |
| Ory-Magne 2014 | P | ≥ 200 mg/day | 3 month | 56 | PD patients with peak-dose dyskinesias, H&Y stages (−) | UPDRS III, IV AIMs | AEs |
| Pahwa 2016 | P | 340 mg/day | 8 weeks | 43 | PD patients with peak-dose dyskinesias, H&Y stages 2.5 ± 0.7 | MDS-UPDRS IV UDysRS | AEs |
All trials included were randomised, double-blind, placebo-controlled trials.
CO, Cross over; P, Parallel design; PD, Parkinson's disease; UPDRS, Unified Parkinson's Disease Rating Scales; AIMs: Abnormal Involuntary Movements Scale; CDRS: Clinical Dyskinesia Rating Scale; DRS: Dyskinesia Rating Scale; UDysRS, Unified Dyskinesia Rating Scale; RDRS, Rush Dyskinesia Rating Scale; MDS-UPDRS, the Movement Disorder Society Unified Parkinson's Disease Rating Scale; H&Y: Hoehn and Yahr Parkinson's disease staging scale; AEs, Adverse Events; H&Y: Hoehn and Yahr Parkinson's disease staging scale; Follow-up indicates the most immediate evaluation time point after the end of treatment for each study. This is different from the maximum follow-up time for each study.