Efficacy and adverse events of antimuscarinics for treating overactive bladder: network meta-analyses

Context: Millions of people worldwide experience overactive bladder (OAB), and antimuscarinics are the pharmacologic treatment of choice. Several conventional meta-analyses have been published, but they fail to quantify efficacy and adverse events across drugs, dosages, formulations, and pharmaceutical forms.

Objective: To perform two network meta-analyses summarizing the efficacy and adverse events of antimuscarinics in the treatment of OAB.

Evidence acquisition: Medline and Scopus searches, previous systematic reviews, conference abstracts, book chapters, and the reference lists of relevant articles were searched. Trialists were contacted. Eligible studies were randomized trials that compared at least one antimuscarinic for treating OAB with placebo or with another antimuscarinic, and that reported efficacy and/or adverse event outcomes. Efficacy was assessed for six outcomes (perception of cure or improvement, urgency episodes per 24h, leakage episodes per 24h, urgency incontinence episodes per 24h, micturitions per 24h, and nocturia episodes per 24h). Adverse events were assessed in seven categories according to the Common Terminology Criteria for Adverse Events. Across all outcomes, a summary efficacy and an adverse event score were computed. Two authors independently extracted data.

Evidence synthesis: For the comparison of the efficacy, 76 trials enrolling 38 662 patients were included; for adverse events, 90 trials enrolling 39 919 patients were included. In the subset of studies reporting on treatments and dosages as used in clinical practice, 40 mg/d trospium chloride, 100mg/g per day oxybutynin topical gel, and 4 mg/d fesoterodine had the best efficacy, while higher dosages of orally administered oxybutynin and propiverine had the least favorable relationship of efficacy and adverse events.

Conclusions: This is the first study allowing trade-offs between efficacy and adverse events of various drugs and dosages in the treatment of patients with OAB. Differences among the various antimuscarinics call for careful, patient-centered management in which regimen changes should be considered.