Efficacy and Safety of Botulinum Toxin A Intradetrusor Injections in Adults with Neurogenic Detrusor Overactivity/Neurogenic Overactive Bladder: A Systematic Review

Abstract

Botulinum toxin A (BoNTA) is increasingly used for therapy of neurogenic detrusor overactivity (NDO) refractory to antimuscarinics or where patients are experiencing antimuscarinic-related side effects. The objective was to compare and critically discuss the reported efficacy and safety of BoNTA in adults with neurogenic bladder dysfunction. Studies published between January 1985 and July 2012 were identified in the MEDLINE (PubMed) and SCOPUS databases. A search for studies with onabotulinumtoxinA--the only formulation of BoNTA approved by the US FDA in adults with NDO--was performed. Exclusion criteria were urethral sphincter injection, no separate analysis between onabotulinumtoxinA and other formulations of BoNTA, mean follow-up ≤ 4 weeks and studies with ten or fewer patients. Clinical and urodynamic parameters for efficacy, adverse events (AEs) and tolerability were reviewed to offer recommendations for practice and future research. A total of 28 included studies revealed superior effects of onabotulinumtoxinA compared with placebo in achieving continence, reducing incontinence episodes, improving urodynamic parameters and health-related quality of life. The most frequently reported AEs were de novo intermittent catheterization, urinary retention and asymptomatic urinary infection. Limitations of this review are the inclusion of studies with the level-3 evidence (22/28 studies), the heterogenicity of outcome parameters and time points chosen for follow-up reported in the reviewed studies. OnabotulinumtoxinA therapy is effective, safe and well tolerated in adults with neurogenic bladder dysfunction. Further high-quality prospective trial data are required to determine the optimal dose, injection technique, long-term safety, favourable timing, indications for re-injections, and the impact of concomitant antimuscarinics on onabotulinumtoxinA therapy.