Safety and Effectiveness of Repeated Botulinum Toxin A Intracavernosal Injections in Men with Erectile Dysfunction Unresponsive to Approved Pharmacological Treatments: Real-World Observational Data

Abstract

Intracavernosal injections of botulinum toxin A (BTX/A ic) may be effective for difficult-to-treat erectile dysfunction (ED). This is a retrospective case series study of the effectiveness of repeated off-label BTX/A ic (onabotulinumtoxinA 100U, incobotulinumtoxinA 100U or abobotulinumtoxinA 500U) in men with ED and insufficient response to phosphodiesterase type 5 inhibitors (PDE5-Is) or prostaglandinE1 intracavernosal injections (PGE1 ICIs), defined as an International Index of Erectile Function-Erectile Function domain score (IIEF-EF) < 26 on treatment. Further injections were performed on patients’ requests, and the files of men who underwent at least two injections were reviewed. The response to BTX/A ic was defined as the achievement of the minimally clinically important difference in IIEF-EF adjusted to the severity of ED on treatment at baseline. Out of 216 men treated with BTX/A ic and PDE5-Is or PGE1-ICIs, 92 (42.6%) requested at least a second injection. The median time since the preceding injection was 8.7 months. In total, 85, 44 and 23 men received, respectively, two, three and four BTX/A ic. The overall response rate was 77.5%: 85.7% in men with mild ED, 79% for moderate ED and 64.3% for severe ED on treatment. The response increased with repeated injections: 67.5%, 87.5% and 94.7%, respectively, after the second, third and fourth injections. Post-injection changes in IIEF-EF were similar across injections. The time from injection to request for a further injection varied little. Four men reported penile pain at the time of injection (1.5% of all injections), and one experienced a burn at the penile crus. Repeated BTX/A injections combined with PDE5-Is or PGE1-ICIs produced an effective and durable response, with acceptable safety.

Concomitant Botulinum Toxin Injections for Neurogenic Detrusor Overactivity and Spasticity—A Retrospective Analysis of Practice and Safety

“…Other indications (either validated or approved or not) could have been considered in our population of interest, such as neuropathic pain, erectile dysfunction and sialorrhea [ 23 , 24 , 25 , 26 ]. However, we focused our analysis on both spasticity and NDOI, which are frequent and well-validated, with known efficacy and safety profiles in our population of interest.…”

Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications

“…In a clinical trial, an increase of 5 to 10% in erectile score in patients receiving BoNT was described [ 91 , 92 ]. Guliano et al evidenced the role of sympathetic hyperactivity in ED which, therefore, can benefit from BoNT injections [ 93 , 94 , 95 , 96 ]. The erection mechanism implies a complex and delicate co-ordinated equilibrium between neurological, vascular and tissular compartments.…”