Efficacy and Safety of Combined Phosphodiesterase Type 5 Inhibitors as a Salvage Medical Treatment in Patients with Erectile Dysfunction after Nerve-Sparing Radical Prostatectomy

Abstract

Purpose Penile rehabilitation therapy using phosphodiesterase type 5 inhibitors (PDE5i) is used widely as a first-line therapy in patients with erectile dysfunction (ED) after radical prostatectomy (RP). However, many patients undergoing such therapy still complain of inappropriate erectile function (EF). Therefore, we evaluated the efficacy and safety of combined PDE5i therapy as a salvage medical treatment in patients nonresponsive to initial penile rehabilitation using daily PDE5i after nerve-sparing RP. Methods We retrospectively reviewed 58 nonresponders (Erection Hardness Score [EHS] of 2 or less) to penile rehabilitation using tadalafil (5 mg) daily for more than 12 weeks and who subsequently received combined PDE5i therapy (tadalafil [5 mg] once daily with sildenafil [50 mg] or udenafil [100 mg] on demand). Success after combined therapy is defined by EHS scores of 3 or 4. Safety was assessed by observing drug tolera-bility and adverse events. Results Of the 58 patients, combined therapy was successful in 39.7% of cases. The mean preoperative International Index of Erectile Function (IIEF-5) score was significantly higher in the success group after combined PDE5i therapy compared with the failure group (success group, 15.9 ± 5.1 versus failure group, 12.3 ± 5.6; p = 0.018). According to ED classification based on preoperative IIEF-5 scores, the success rates of no/mild/mild-to-moderate ED group and moderate/severe ED group were 50.0% (18/36) and 22.7% (5/22), respec-tively (p = 0.039). The success and failure groups did not differ significantly in any other characteristic. The drugs were tolerated well by all patients and no serious adverse events were observed. Conclusion Combined PDE5i therapy improves EF in patients nonresponsive to standard penile rehabilitation using daily PDE5i after nerve-sparing RP, especially for patients without preoperative moderate or severe ED. In such patients, combined PDE5i therapy could be considered before invasive therapies.