Outcomes of Intravesical Botulinum Toxin for Idiopathic Overactive Bladder Symptoms: A Systematic Review of the Literature

Purpose: We systematically reviewed the evidence for the efficacy and safety of botulinum toxin in the management of overactive bladder. Materials and Methods: We performed a systematic review of the literature to identify articles published between 1985 and March 2009 on intravesical botulinum toxin-A injections for the treatment of refractory idiopathic overactive bladder in men and women. Databases searched included MEDLINE (R), CENTRAL and Embase (R). Data were tabulated from case series and from randomized controlled trials, and data were pooled where appropriate. Results: Our literature search identified 432 titles and 23 full articles were included in the final review. Three randomized placebo controlled trials addressing the use of botulinum toxin-A were identified (99 patients total). The pooled random effects estimate of effect across all 3 studies was 3.88 (95% CI -6.15, -1.62), meaning that patients treated with botulinum toxin-A had 3.88 fewer incontinence episodes per day. Urogenital Distress Inventory data revealed significant improvements in quality of life compared with placebo with a standardized mean difference of -0.62 (CI -1.04, -0.21). Data from case series demonstrated significant improvements in overactive bladder symptoms and quality of life, despite heterogeneity in methodology and case mix. However, based on the randomized controlled trials there was a 9-fold increased odds of increased post-void residual after botulinum toxin-A compared with placebo (8.55; 95% CI 3.22, 22.71). Conclusions: Intravesical injection of botulinum toxin resulted in improvement in medication refractory overactive bladder symptoms. However, the risk of increased post-void residual and symptomatic urinary retention was significant. Several questions remain concerning the optimal administration of botulinum toxin-A for the patient with overactive bladder.