Efficacy of Intracavernosal Injections of 50-Unit versus 100-Unit Doses of AbobotulinumtoxinA (Masport®) in Vasculogenic Erectile Dysfunction with Phosphodiesterase Type 5 Inhibitors Resistant

Background: We aimed to evaluate the safety and efficacy of 50-unit dose against 100-unit dose of intracavernosal injection (ICI) of AbobotulinumtoxinA (BTX-A) (Masport®) in patients with vascular erectile dysfunction (ED) resistant to first-line therapies, including phosphodiesterase type 5 inhibitors (PDE5I). Methods: In this double-blind randomized controlled trial (RCT), 40 patients with ED resistant to PDE5I were randomly divided into two groups: ICI of a single dose of Masport® 50 units and single dose of 100 units. Peak systolic velocity (PSV) confirmed arterial insufficiency vascular disorder. For all patients, IIEF (International Index of Erectile Function), SHIM (Sexual Health Inventory for Men), and EHS (Erection Hardness Score) questionnaires were completed. Six weeks after the treatment, the subjects were re-examined. Results: Our results showed an acceptable clinical efficacy and safety of ICI of Masport® six weeks after injection. No systemic complications in patients were seen. Three patients complained of brief penile pain shortly after injection, but there were no other local complications. The increase in mean PSV in the 100-unit group due to treatment was significant (P-value < 0.0001). Also, there was a significant difference between the two groups of 50- and 100-unit (P-value < 0.0001). In addition, the increase in mean IIEF-EF, SHIM score, and EHS due to treatment was significant between the two groups. For the 100-unit group, P-value < 0.0001 and the difference between the two groups was also significant (P-value < 0.0001), which indicated a better response to treatment in the 100-unit group. The mean increase of IIEF score (EF domain) was 4.3 (mean IIEF: 9.4 and 13.7 after and before, respectively) in the 100-unit group and (mean IIEF: 8.1 and 9.1 after and before, respectively) in the 50-unit group. Conclusions: The results of this study showed that ICI of AbobotulinumtoxinA, especially at a dose of 100 units, in patients with refractory vasculogenic ED is safe and effective in improving sexual function and ultrasound indices.