Botulinum neurotoxin A for male lower urinary tract symptoms

Abstract

Purpose of review: Lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH) affects a large number of male patients from 45 years onward, increasing with age. Routine medical treatment is mainly limited to plant extracts, α-blockers, and 5-α-reductase inhibitors. Although all types of drug have a proven efficacy, they often do not sufficiently treat all aspects of LUTS related to BPH. Thus, there is a need for alternatives. Intraprostatic injections with botulinum neurotoxin type A (BoNT/A) seem to be a promising alternative. The purpose of this review is to summarize the most recent findings from basic science and clinical studies in relation to BoNT/A application in BPH-related LUTS, thereby providing insight into the putative mechanism of action, the rationale for the use of BoNT/A in BPH-related LUTS, and the clinical outcomes.

Recent findings: There is some evidence that BoNT/A intraprostatic injections affect both, the static and dynamic component of BPH-related LUTS by reducing the prostate volume and by downregulation of α-1A-adrenoreceptors. Clinical trials demonstrated an easy and minimally invasive intraprostatic application of BoNT/A with a favourable safety profile. Efficacy seems to be good with significant improvements for several months in symptoms, urinary flow rate and reduction in postvoid residual, prostate volume, and also prostate-specific antigen in some studies.

Summary: BoNT/A seems to be a promising alternative in the treatment of BPH-related LUTS with a good tolerance and safety profile. However, the level of evidence is still low and further randomized controlled studies are mandatory.