A prospective, randomized, open-label, parallel trial comparing the efficacy of α-blocker or 5α-reductase inhibitor withdrawal to continued combination therapy on the maintenance of lower urinary tract symptoms in men with benign prostatic hyperplasia.

Background: It is uncertain how long combination therapy should be continued in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). We investigated the withdrawal effects of α1-adrenergic receptor blocker (AB) or 5α-reductase inhibitor (5ARI) following successful combination therapy.

Methods: This prospective, randomized, open-label, parallel trial enrolled 222 patients with BPH/LUTS who showed at least a seven-point improvement in International Prostate Symptom Score-total (IPSS-T) and a ≥ 20% reduction in prostate volume (PV) following the initiation of combination therapy. Patients were randomized in a 1:1:1 ratio into continued-combination, AB-withdrawal, and 5ARI-withdrawal groups. IPSS, overactive bladder symptom score, EuroQol-five-dimensional questionnaire (EQ-5D-5L), EuroQol-visual analog scale (EQ-VAS), prostate volume (PV), maximal flow rate, postvoid residual urine (PVR), and prostate-specific antigen level were assessed every 6 months for 24 months. The predictors of IPSS-T deterioration were evaluated.

Results: At Month 24, IPSS-T deterioration (≥2 point) was observed in 20/72 (27.8%) and 19/72 (26.4%) patients in the AB- and 5ARI-withdrawal groups, respectively. Among them, 4/72 (5.6%) and 4/70 (5.7%) patients required readdition of the withdrawn drug (p = 0.868). In the continued combination group, EQ-VAS improved at Month 24 compared to baseline (p = 0.028). At Month 24, the AB-withdrawal group showed improvements in EQ-5D-5L, EQ-VAS, and PVR (all p < 0.005), while the 5ARI-withdrawal group showed improvement in IPSS-S (p = 0.011). Diabetes mellitus was associated with IPSS-T deterioration at Month 24 (p = 0.020).

Conclusions: In patients with BPH/LUTS who are reluctant to continue combination therapy, AB or 5ARI withdrawal may be offered in men with improvement in IPSS-T by at least seven points and reduction in PV by at least 20%.