Comparative Effectiveness of Botulinum Toxin a Versus Placebo for Neurogenic Overactive Bladder: A Meta‐Analysis

BACKGROUND: Lower urinary tract (LUT) dysfunctions affect millions of patients globally. LUT dysfunctions are extremely common in patients with neurological diseases. Worldwide, subtype A of Botulinum Toxin A (BTXA) is regularly used to treat these disorders. INTRODUCTION: LUT dysfunctions have various patterns of expression. The most prevalent of these is neurogenic detrusor overactivity (NDO), which is strongly associated with neurological diseases and can significantly impact a patient's life. OBJECTIVE: Onabotulinumtoxin A is a widely used drug for the treatment of neurogenic bladder. The purpose of this study is to evaluate its efficacy and safety across different dosages in patients with the condition. DATA SOURCES: Pubmed, Scopus, Web of Science. REVIEW METHODS: Systematic literature review was performed to identify randomized, double-blind, placebo-controlled trials of onabotulinumtoxin A for NDO. Seven randomized controlled trials were incorporated in this meta-analysis. The primary outcome concerned urodynamic parameters, including Maximum Cystometric Capacity (MCC) and Maximum Detrusor Pressure (MDP); the mean number of Urinary Incontinence (UI) episodes per week was also assessed. Safety was evaluated by the incidence of various Adverse Events (AE). Data was extracted by two authors and statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS v.29). RESULTS: Seven RCTs involving 1592 patients in total were included in the study, following screening of 1602 potentially relevant articles. The Onabotulinumtoxin A-treated groups showed a significant increase in MCC (Mean Difference ([MD]: 128.866, 95% Confidence Interval [CI]: 98.836, 158.896, p < 0.001, in the group that received 200 Units of Onabotulinumtoxin A; MD: 151.389, CI: 106.006, 196.773, p < 0.005, in the group that received 300Units of Onabotulinumtoxin A). There was also a significant decrease in MDP in the Onabotulinumtoxin A-treated groups (MD: -29.051, CI: -39.557, -18.545, p < 0.002, 200 U group; MD: -31.751, CI: -45.226, -18.276, p < 0.01, 300 U group). Additionally, no effect was noticed in the mean number of UI episodes per week (MD: -10.69, 95% CI: -33.86, 12.49, p = 0.11; MD: -10.55, 95% CI: -59.06, 37.97, p = 0.22, 200 U and 300 U respectively). Taking AEs into consideration, Onabotulinumtoxin A-treated groups were often associated with more complications, including urinary tract infections (UTI) (LogOR: 0.341, CI: 0.011, 0.67, p = 0.045, 200 U group; LogOR: 0.424, CI: 0.075, 0.773, p = 0.028, 300 U group) and urinary retention (UR) (LogOR: 1.746, CI: 0.869, 2.623, p = 0.008, 200 U group; LogOR: 1.879, CI: 0.679, 3.078, p = 0.021, 300 U group). CONCLUSIONS: Our meta-analyses found that Onabotulinumtoxin A can be beneficial in improving the urodynamic parameters (MCC and MDP). As far as safety is concerned, the drug-treated groups had a slightly higher likelihood of developing UTI or UR.