The effectiveness and safety of intracavernosal botulinum toxin injections in the management of erectile dysfunction: a systematic review and meta-analysis of clinical studies.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials and observational studies
PubMed 40330908 · doi:10.1093/sexmed/qfaf034
What was done
A systematic review and meta-analysis (PRISMA 2020) evaluated the efficacy and safety of intracavernosal botulinum neurotoxin serotype A (BoNT-A: onabotulinumtoxinA, abobotulinumtoxinA, and incobotulinumtoxinA) in adult men with erectile dysfunction. Study risk of bias was assessed using Joanna Briggs Institute (JBI) checklists. Outcomes evaluated included changes in IIEF-EF, SHIM, and Erection Hardness Score, minimal clinically important difference (MCID) response rates, and penile Doppler ultrasound parameters.
What was found
Six studies met inclusion criteria: 2 randomized controlled trials (RCTs) and 4 retrospective studies. Across all three BoNT-A formulations, the overall response rate was 77.5% (no statistically significant difference between formulations), and at least 40% of patients achieved an MCID (2 to 7 point increase in IIEF-EF/SHIM) at ≥1 month. For abobotulinumtoxinA, 500 U sustained effect longer than 250 U. OnabotulinumtoxinA improved peak systolic velocity on Doppler ultrasound compared with saline. Meta-analysis of the 2 RCTs demonstrated a significant improvement in SHIM score at 12 weeks favoring onabotulinumtoxinA over saline (mean difference 4.35, P = .008). No systemic adverse events were reported; infrequent local transient penile pain occurred, along with a single reported case of priapism.
Why it matters
Intracavernosal BoNT-A shows potential as an effective non-surgical therapeutic option for patients with erectile dysfunction who are refractory to conventional pharmacotherapies.
Limits
The total evidence base is very small (only 2 RCTs and 4 retrospective studies, with total patient count omitted from the abstract). Heterogeneity in inclusion criteria and outcome reporting across studies restricted the meta-analysis, and long-term durability and comparative dosing regimens remain poorly defined.
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