Intracavernosal Botulinum Toxin Injection for Erectile Dysfunction: A Comprehensive Systematic Review

Area of Science:

• Urology
• Pharmacology
• Regenerative Medicine

Background:

• Erectile dysfunction (ED) affects 20% of men globally, impacting quality of life.
• Phosphodiesterase type 5 inhibitors (PDE5-Is) are first-line treatments, but many patients are non-responders.
• Intracavernosal alprostadil is effective but invasive; intracavernosal onabotulinumtoxinA (BoNT-A) presents a novel alternative.

Purpose of the Study:

• To systematically review the efficacy and safety of intracavernosal onabotulinumtoxinA (BoNT-A) for treating erectile dysfunction (ED).
• To evaluate BoNT-A as a potential therapeutic option for patients with refractory ED.
• To assess the potential of BoNT-A to reduce treatment burden and improve adherence.

Main Methods:

• A systematic review adhering to PRISMA guidelines was conducted.
• Searches were performed across major databases (PubMed, Embase, Cochrane, Scopus, Clinicaltrials.gov) using relevant keywords and MeSH terms.
• 51 studies were included, with data synthesized via narrative synthesis due to heterogeneity.

Main Results:

• Intracavernosal BoNT-A demonstrated improvements in erectile function scores across studies.
• Reported response rates varied from 40% to 77.5%.
• The treatment showed a favorable safety profile, with mild penile pain as the most common adverse event; no serious systemic events were reported.

Conclusions:

• Intracavernosal onabotulinumtoxinA (BoNT-A) may be a beneficial option for refractory ED patients.
• BoNT-A offers potential improvements in sexual function and reduces reliance on invasive therapies.
• Further large-scale, placebo-controlled trials are needed to confirm efficacy and standardize clinical use.