To investigate the efficacy of dutasteride add-on treatment to tadalafil in patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic enlargement (BPE).
A prospective study was conducted in patients with BPE who had not been satisfied with tadalafil monotherapy for more than 3 months. Inclusion criteria were prostate volume (PV) ≥ 30 ml and IPSS ≥ 8 or QOL index ≥ 3 under administration of tadalafil without anticholinergic agent. Before and 24 weeks after dutasteride add-on treatment to tadalafil, we assessed IPSS, overactive bladder symptom score (OABSS), serum PSA and testosterone, and uroflowmetry (UFM) to compare these parameters before and after dutasteride add-on treatment. Using a propensity-score matching analysis, the efficacy of dutasteride add-on treatment to tadalafil was compared with the previous study of dutasteride add-on treatment to alpha blocker.
Of 52 patients who were enrolled in this study, 48 patients completed the study (mean age: 72 ± 5 years old). Dutasteride add-on treatment to tadalafil significantly improved IPSS (from 16.4 ± 5.2 to 13.3 ± 6.4) and IPSS-QOL (from 4.0 ± 1.2 to 3.3 ± 1.1), and reduced PV from 55 ± 26 to 39 ± 22 ml. Propensity-score matching identified 42 matched pairs of patients. The improvement rate of IPSS and reduction rate of PV were similar between patients treated with dutasteride add-on treatment to tadalafil and dutasteride add-on treatment to alpha blocker. The logistic regression analysis showed that PV at baseline and reduction rate of PV after treatment were associated with the effective symptomatic outcome.
The dutasteride add-on is a reasonable treatment option for male patients with LUTS who are not satisfied with tadalafil monotherapy.

© 2022. The Author(s), under exclusive licence to Springer Nature B.V.