The effect of combination treatment with low-intensity shockwave therapy and daily tadalafil on severe erectile dysfunction: a double-blind, randomized, sham-controlled clinical trial

Abstract

Abstract Background Patients with severe erectile dysfunction (ED) remain the most challenging group in terms of available noninvasive treatment modalities. Aim The study sought to assess the role of combination therapy with low-intensity shockwave therapy (LiST) and daily tadalafil 5 mg in a highly select group of patients with severe vasculogenic ED through a double-blind, randomized trial. Methods Forty-eight sexually active men were randomly assigned to 12 sessions of LiST 3 times weekly and tadalafil 5 mg once daily (n = 34) or sham therapy and tadalafil (n = 17) for 4 weeks. Patients were assessed at 1 and 3 months after completion of treatment. Outcomes Improvement of erectile function was evaluated through the International Index of Erectile Function–Erectile Function domain (IIEF-EF) or 6-item IIEF and the Sexual Encounter Profile (SEP) diary. The primary outcome was the difference between the groups in the IIEF-EF at 3 months after completion of treatment. Secondary outcomes comprised (1) the difference between the groups in the IIEF-EF at 1 month after completion of treatment, (2) the difference between the groups in the “yes” responses to question 3 of the SEP diary at 1 and 3 months, and (3) the treatment-related adverse events. The number of patients attaining a minimal clinically important difference in the IIEF-EF (improvement of at least 7 points) was also assessed. Results After treatment, the absolute scores in the IIEF-EF were higher in patients receiving LiST and tadalafil vs sham therapy and tadalafil both at the 1-month (12.1 ± 2.4 vs 10.2 ± 1.7; P = .002) and at the 3-month (12.9 ± 2.1 vs 10.8 ± 1.8; P < .001) evaluation. Between the 2 groups, the proportion of “yes” responses to question 3 of the SEP diary was not statistically significant, whereas the number of patients attaining a minimal clinically important difference in the IIEF-EF was statistically significant only at the 3-month evaluation. No adverse events occurred. Clinical Implications Application of LiST in patients with severe vasculogenic ED receiving daily dose tadalafil may further improve erectile function compared with tadalafil as a stand-alone treatment on the short term. Strengths and Limitations Although we provided the first study in the field, severe vasculogenic ED was defined based on medical history and clinical examination and not based on penile ultrasound measures. Conclusion The combination of 12 sessions LiST 3 times weekly and daily tadalafil for 4 weeks led to a 2-point difference in the IIEF-EF compared with sham therapy and daily tadalafil among patients with severe vasculogenic ED after 1 and 3 months from completion of treatment.