Botulinum Toxin A (Botox®) Intradetrusor Injections in Adults with Neurogenic Detrusor Overactivity/Neurogenic Overactive Bladder: A Systematic Literature Review

ObjectivesThis systematic literature review discusses the efficacy and safety of botulinum toxin type A (Botox®) intradetrusor injections in adults with neurogenic detrusor overactivity (NDO) and urinary incontinence or overactive bladder symptoms of neurogenic origin (NOAB).MethodsA MEDLINE and EMBASE search for clinical studies with botulinum toxin A injected into the detrusor of adults with NDO was performed. For several efficacy and safety variables data were extracted by one person and independently quality-controlled by another person. Extracted data were reviewed to propose recommendations for use in clinical practice based on level of evidence and expert opinion.ResultsA total of 18 articles evaluating the efficacy or safety of Botox in patients with NDO and incontinence/NOAB resistant to antimuscarinic therapy, with or without clean intermittent self-catheterisation (CIC), were selected. The amount of Botox injected was mostly 300 U, usually as 30 injections of 10 U/ml in the bladder (excluding the trigone) under cystoscopic guidance and with different types of anaesthesia. Most of the studies reported a significant improvement in clinical (approximately 40–80% of patients became completely dry between CICs) as well as urodynamic (in most studies mean maximum detrusor pressure was reduced to ≤40 cm H2O) variables and in the patients’ quality of life, without major adverse events.ConclusionsBotox injections into the detrusor provide a clinically significant improvement in adults with NDO and incontinence/NOAB refractory to antimuscarinics. It seems to be very well tolerated. However, more adequately powered, well-designed, randomised, controlled studies evaluating the optimal dose, number and location of injections, impact on antimuscarinic regimen and CIC use, duration of effect, and when to perform repeat injections are warranted.