Long term effectiveness and safety of intracavernosal botulinum toxin a as an add-on therapy tophosphosdiesterase type 5 inhibitors or prostaglandin e1 injections for erectile dysfunction – a case series study

Abstract

<h3>Objectives</h3> Some evidence suggests that intracavernosal botulinum toxin A (BTX-A IC) injections in addition to phosphodiesterase type 5 inhibitors (PDE5-Is) or prostaglandin E1 intracavernosal injections (PGE1 ICI) could effectively treat ED in insufficient responders to these pharmacological treatments. To determine long-term effectiveness and safety of combined treatment involving a single injection of BTX-A IC as an add on therapy to PDE5-Is or PGE1-ICIfor the treatment of ED of different etiologies. <h3>Methods</h3> Retrospective, uncontrolled, single center study. Data from 123 consecutive patients with ED who were insufficient responders to PDE5-Is or PGE1-ICI and who received onabotulinumtoxinA 100 U, abobotulinumtoxinA 250 U or 500 U IC as an add on to their current pharmacological treatment. All analyses were exploratory. Qualitative data compared using a Mann Whitney test or Wilcoxon signed rank test. Kruskal-Wallis tests performed to select variables for Odds Ratio (OR) calculations following logistic regression. <h3>Results</h3> Minimally clinically important difference (relative to baseline severity of ED) in the IIEF-EF score achieved in 50% of patients at 34 [27-42] days and in 38% at 5.9 [3.9 – 8.2] months following BTX-A IC in combination with PDE5-Is or PGE1 ICI. Severity of ED influenced response to BTX-A IC more than etiology. Post prostatectomy and higher IIEF-EF severities were risk factors: OR=0.34, IC[95%] = [0.12 - 0.93] and OR=0.32, IC[95%] = [0.15 - 0.67] respectively. The type of BTX-A did not affect the response. Effectiveness tended to decrease more over time with abobotulinumtoxinA 250 U than 500 U. The only side-effects were mild penile pain on injection (n=1) and mild penile pain for 3 days following injection (n=1); no systemic effects reported. <h3>Conclusions</h3> BTX-A IC administered as an add on to registered pharmacological treatments improved erection for at least 6 months in 38% of patients with ED of varying etiologies, and was safe. <h3>Conflicts of Interest</h3> No Conflict of interest