Efficacy and safety of botulinum toxin A intradetrusor injections in adults with neurogenic detrusor overactivity/neurogenic overactive bladder: a systematic review.

BACKGROUND: 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.

OBJECTIVE: The objective was to compare and critically discuss the reported efficacy and safety of BoNTA in adults with neurogenic bladder dysfunction.

DATA SOURCES: Studies published between January 1985 and July 2012 were identified in the MEDLINE (PubMed) and SCOPUS databases.

STUDY SELECTION, STUDY APPRAISAL AND SYNTHESIS METHODS: 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.

RESULTS: 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: 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.

CONCLUSIONS: 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.