The Effect of Combination Treatment With Low-Intensity Shockwave Therapy and Tadalafil on Mild and Mild-To-Moderate Erectile Dysfunction: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

Abstract

Combination of different first-line treatments for erectile dysfunction (ED) has emerged as a promising therapeutic approach. To conduct the first double-blind, randomized, placebo-controlled clinical trial to evaluate the efficacy and safety of combination therapy with low-intensity shockwave therapy (LiST) and tadalafil vs LiST and placebo in patients with mild or mild-to-moderate vasculogenic ED. Fifty sexually active patients fulfilling the eligibility criteria were randomly assigned to 6 sessions of LiST twice weekly for 3 weeks and tadalafil (n = 25) or placebo (n = 25) once daily for 4 weeks. Patients were evaluated at 1, 3, and 6 months after completion of the treatment protocol. The primary outcome was the mean change from baseline in the International Index of Erectile Function-Erectile Function (IIEF-EF) domain between the 2 groups at 3 months after treatment. Erectile function was also assessed at 1 and 6 months. The number of patients attaining a minimal clinically important difference (MCID) in the IIEF-EF, as well as the safety of combination therapy were evaluated. Adjusting for the baseline values, IIEF-EF improved by 0.8 points more (95% confidence interval [CI] = -0.2 to 1.9, P = .12) at 1 month, 1 point more (95% CI = 0.1-1.9, P = .02) at 3 months and 1.7 points more (95% CI = 0.8-2.7, P < .001) at 6 months in patients treated with combination therapy compared to monotherapy. The number of patients attaining a MCID in the IIEF-EF between the 2 groups improved significantly only at the 3-month evaluation. No adverse events were reported during the whole study period. Combination of LiST twice weekly for 3 weeks and tadalafil 5 mg once daily for 4 weeks may further ameliorate mild or mild-to-moderate vasculogenic ED compared to LiST monotherapy. We conducted the first randomized trial exploring the role of LiST and tadalafil in the management of ED. Conversely, our study lacks external validity due to its single-center design. The addition of daily low-dose tadalafil during application of LiST may further improve erectile function compared to application of LiST as a standalone treatment in patients with mild or mild-to-moderate vasculogenic ED. Still, further high-quality studies are warranted to corroborate our findings.