[Botulinum toxin injection for refractory non-neurogenic overactive bladder. Systematic review]

OAB is common with a potential negative impact on quality of life. Anticholinergics and β3-mimetics are the first-line medical treatment. This treatment meets only 50% of patients given a lack of efficacy and adverse effects. Used in the treatment of neurogenic overactive bladder, botulinum toxin is now evaluated for the treatment of refractory non-neurogenic overactive bladder. The objective of this work is to review the literature data concerning the efficacy and safety of intradetrusor botulinum toxin injections to treat refractory idiopathic overactive bladder.

A systematic literature review was conducted to identify articles published between May 1988 and April 2013 in Medline for the treatment of refractory idiopathic overactive bladder with botulinum toxin.

37 studies with original samples were selected including 8 randomized controlled trials against placebo. The effectiveness of intra- detrusor injections is demonstrated to reduce the frequency, urgency, nighttime urination, incontinence episodes and to improve bladder capacity and quality of life. The most common side effects are incomplete bladder emptying, intermittent catheterization and increased risk of urinary tract infection. A dose of 100 to 150 U of onabotulinumtoxinA allows the best compromise between efficiency and tolerance. Duration of the effects varies between 3 to 12 months and repeating the injections did not seem to affect the efficiency. Injections including the trigone zone do not cause vesicoureteral reflux. The absence of detrusor hyperactivity does not alter the clinical response.

The detrusor injections of botulinum toxin can be considered as an effective second-line treatment for refractory non-neurogenic overactive bladder. Information on intermittent catheterization risk must be provided. The very long-term effectiveness and the absence of urothelium alterations are still outstanding issues.