Efficacy of low-intensity shockwave therapy with different tadalafil regimens in patients with PDE5 inhibitor-resistant erectile dysfunction: a retrospective cohort study

Purpose Currently, there is a lack of research comparing tadalafil treatment protocols recommended during low-intensity shock wave therapy (LI-SWT) for patients with erectile dysfunction (ED) who are unresponsive to phosphodiesterase type 5 inhibitors (PDE5i). The objective of this study is to compare the efficacy of only LI-SWT versus LI-SWT plus 5 mg tadalafil daily versus LI-SWT plus 20 mg tadalafil alternate-day in PDE5i-resistant ED. Materials and methods In this study, a cohort of 105 patients with PDE5i-resistant ED was recruited and divided into three groups labeled as A (only LI-SWT), B (LI-SWT plus 5 mg tadalafil daily), and C (LI-SWT plus 20 mg tadalafil alternate-day), comprising 27, 42, and 36 patients, respectively. The patients' International Index of Erectile Function-5 (IIEF-5) scores and the Erection Hardness Score (EHS) were evaluated at the baseline, three months and six months following the treatment.Results After three months post-treatment, the IIEF-5 scores in group A, B, and C increased by 4.1 +/- 0.6, 7.3 +/- 0.6, and 8.2 +/- 0.6, respectively. These improvements were maintained at six months with IIEF-5 scores increasing by 3.7 +/- 0.6, 7.3 +/- 0.6, and 8.5 +/- 0.7 in groups A, B, and C, respectively. At 3 and 6 months post-treatment, groups B and C showed significant improvement in IIEF-5 scores and EHS values compared to group A (p < 0.001). The rate of patients with EHS > 3 and IIEF-5 > 17 was significantly higher in groups B and C compared to group A, while there was no significantly different between groups B and C.Conclusion In patients with PDE5i-resistant ED, PDE5i combined with LI-SWT is superior to LI-SWT monotherapy. The statistical analysis failed to demonstrate any difference between two distinct tadalafil regimens when administered with LISWT treatment.