(O-22) Intracavernosal botulinum toxin for erectile dysfunction: preliminary results from a double-blind, randomized controlled trial

Abstract Introduction/Objective Erectile dysfunction (ED) affects quality of life and has limited response to conventional treatments in ~30% of patients. Botulinum toxin (BT), a neuromodulator with smooth muscle relaxation effects, has shown potential in early studies. This study aims to assess the safety and efficacy of intracavernosal BT for ED in patients unresponsive to standard therapy. Materials and Methods This is a prospective, double-blind, randomized study comparing BT (100 U) vs. placebo (saline) injected into the penile shaft. Male participants aged ≥18 with IIEF-5 ≤ 21 and using standard ED treatments were eligible. Exclusion criteria included genitourinary neoplasms, radical prostatectomy, hypogonadism (testosterone <350 ng/dL), anatomical abnormalities, and low sexual activity. Outcomes were assessed at 1, 3, 6, and 12 months post-injection using IIEF-5 scores. Four patients were lost to follow-up (16%), resulting in 21 evaluable cases (BT: n = 11; placebo: n = 10). After 6 months, blinding was lifted and crossover was allowed. Results Baseline IIEF-5 scores were comparable between groups (Placebo: 10.5; BT: 10.4; p = 0.859; Mann–Whitney U test). At 3 months, both groups improved (Placebo: 13.8; BT: 14.6; p = 0.878), with no significant difference between them. However, intra-group analysis using the Wilcoxon signed-rank test showed a significant increase in IIEF-5 scores in the BT group (p = 0.028), while the placebo group showed only a trend (p = 0.091). At 6 months, scores remained elevated (Placebo: 12.6; BT: 13.3; p = 0.806). Conclusions Intracavernosal BT appears safe and well tolerated, with promising clinical improvement in patients with ED refractory to conventional therapy. While intergroup comparisons showed no statistical difference, intra-group analysis suggests sustained benefit with BT. Larger trials are needed to confirm these findings. Financing No conflict.