The use of botulinum toxin in benign prostatic hyperplasia

Abstract

The injection of Botulinum toxin type A (BoNT/A) into the prostate is a minimally invasive alternative treatment for lower urinary tract symptoms. To summarize the action mechanisms of BoNT/A on experimental animals and to analyze its effectiveness according to published clinical studies, we located 24 papers on the treatment of HBP with BoNT/A. The doses applied ranged from 100 (OnabotA) to 600 U (OnabotA and AbobotA). The IPSS score presented a mean post-treatment reduction, for all series, of 10.8 + 2.66 points. Other significant results included the overall mean reduction in QoL score of 2.1 ± 0.62 points, and the pre and post-treatment differences in prostate volume (22.43 ± 20.2 cm(3)), post-voiding residue (76.77 + 51.72 cm(3)) and PSA (1.15 + 0.93 ng/ml). However, only two clinical trials were on sufficient quality to be selected for meta-analysis, and it was observed that the difference of the means, pre- and post-treatment of maximum flow, prostate volume, IPSS and PSA were not statistically significant (P = 0.18). Neither was there any statistically significant difference between pre- and post-treatment post-voiding residue (P = 0.65). In conclusion, BoNT/A alleviates lower urinary tract symptoms due to HBP, but different studies present considerable variations regarding the dose administered, inclusion criteria and follow-up time, as well as poorly defined retreatment, losses to follow up and, above all, a high degree of variability in the communication of results (with large standard deviations). In consequence, further clinical trials are needed.

A Randomized Double-blind Placebo-controlled Phase 2 Dose-ranging Study of OnabotulinumtoxinA in Men with Benign Prostatic Hyperplasia

“…Notably, no changes in PSA values were observed within the treatment groups over the 72-wk duration of the study. However, the relationships between treatment-associated decreases in TPV and PSA are not well defined [8].…”

“…Because most other published studies of botulinum toxins in LUTS/BPH were performed in patients previously treated with a-blockers [8,9], we performed an exploratory post hoc analysis in this subgroup. Previous oral BPH treatment was not required for entry in this study; however, a large number of those enrolled (180 of 380) had been previously treated with a-blockers.…”

“…Because commonly used oral medications such as a-blockers and 5a-reductase inhibitors (5-ARIs) have limitations, including the requirement for daily dosing, many patients switch or discontinue therapy because of the loss of efficacy over time or side effects [2]. The use of botulinum toxins for the treatment of LUTS/BPH has been explored as a minimally invasive alternative in those men not responding to oral therapies and/or who do not want surgery; however, almost all trials investigating the use of botulinum toxins in LUTS/ BPH were small [3][4][5][6][7][8][9], and only one 30-patient study was placebo controlled [3].…”

Transperineal intraprostatic injection of botulinum neurotoxin A vs transurethral resection of prostate for management of lower urinary tract symptoms secondary to benign prostate hyperplasia: A prospective randomised study

“…The patient was positioned in lithotomy and the perineal region was sterilised with povidone iodine, and using TRUS guidance a 22-G spinal needle was inserted transperineally and 1-mL of the prepared solution was injected in each lobe [22]. Patients were asked to continue drug therapies for BPH for 3-weeks after which the clinical effect of the BoNT-A injection should manifest, as documented by Marchal et al [23].…”

Novel intraprostatic injectable agents in the treatment of BPH

“…Reported side effects of the procedure include urinary tract infection and/ or urosepsis, acute urinary retention and haematuria [35] . There have been no reported effects on sexual function [10,39,40] . Limitations of the existing research into intra-prostatic botulinum toxin include a significant placebo effect, limited follow-up, lack of randomisation and/or systematic evaluation of appropriate dose regimens [41] .…”