Introduction and hypothesisThe goal of this meta-analysis was to determine the efficacy and safety of medication for treating overactive bladder (OAB) in patients with Parkinson's disease (PD).MethodsPapers containing predefined key terms were searched in the PubMed, Embase, Web of Science, and Cochrane Library databases up to December 2021 to collect randomized double-blind placebo-controlled trials (RCTs). The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements. Two reviewers independently assessed the risk of bias using the modified Jadad scale and Cochrane risk-of-bias tool. The GRADEpro GDT was employed to evaluate the strength of evidence based on the findings of this meta-analysis.ResultsWe eventually included four RCTs involving 313 patients (163 patients in the medication group and 150 patients in the placebo group). Of these, the therapeutic agent in two RCTs was mirabegron (121 and 106 patients and controls, respectively, representing 3/4 -2/3 of the patients). The results showed that the number of micturition episodes per 24 h (MD -1.33; 95% CI -2.30 to -0.36; p = 0.007), the number of nocturia episodes per 24 h (MD -0.33; 95% CI -0.58 to -0.08; p = 0.009) and the number of urinary incontinence episodes per 24 h (MD -0.72; 95% CI -1.32 to -0.12; p = 0.02) were significantly lower in the medication group than in the placebo group. The OAB symptom score (MD -2.84; 95% CI -4.67 to -1.00; p = 0.002) and quality of life score (MD 15.15; 95% CI 12.33 to 17.96; p < 0.0001) of the medication group were significantly improved compared with those of the placebo group. However, no significant difference in the daily frequency of urinary urgency episodes was identified between the medication group and the placebo group (MD -0.79; 95% CI -1.71 to 0.14; p = 0.09). There were no significant differences between the two groups in terms of drug-related adverse events (OR 1.69; 95% CI 0.41 to 6.99; p = 0.47), especially in PD patients receiving mirabegron therapy.ConclusionsMedication was effective for OAB symptoms in patients with PD, and patients tolerated adverse events well.