Treatment persistence with a fixed-dose combination of tadalafil (5 mg) and tamsulosin (0.4 mg) and reasons for early discontinuation in patients with benign prostatic hyperplasia and erectile dysfunction.

Purpose: The primary aim of this study was to assess treatment persistence with a fixed-dose combination (FDC) of tadalafil (5 mg) and tamsulosin (0.4 mg). This study also evaluated the reasons for early treatment discontinuation. Materials and Methods: This retrospective observational study included patients with benign prostatic hyperplasia and erectile dysfunction who started an FDC treatment of tadalafil (5 mg) and tamsulosin (0.4 mg) between July 2017 and February 2018. Treatment persistence and reasons for early discontinuation were evaluated during the first 6 months. The cumulative discontinuation rate and differences in various parameters were assessed using Kaplan-Meier analysis and the log-rank test, respectively. Factors related to persistence were analyzed using a Cox proportional hazard model. Results: Overall, 97 patients were included in the study. The cumulative persistence rate at 30, 90, and 180 days was 88.7%, 66.0%, and 54.6%, respectively. The cumulative persistence over 6 months differed significantly according to the administration of FDC therapy (log-rank p=0.005) and age (log-rank p=0.024). Younger patients (odds ratio, 2.049; p=0.021) and treatment-naive patients (odds ratio, 2.461; p=0.006) were more likely to discontinue therapy within 6 months. The common reasons for discontinuing therapy were side effects (63.6%) and perceived poor efficacy (22.7%). Conclusions: Side effects were reported to be the main reason for treatment discontinuation. Thus, to improve compliance for a once-daily FDC of tadalafil (5 mg) and tamsulosin (0.4 mg), it is recommended to select patients who show adaptation to a combination of α-blockers and phosphodiesterase type 5 inhibitors prior to FDC treatment.