Efficacy of Adding Dutasteride to α-Blocker Therapy Treated Benign Prostatic Hyperplasia Patients with Small Volume Prostate (<30 mL).

Objectives: To assess the efficacy of dutasteride add-on therapy for patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) with small prostates who have been treated with α-blocker therapy for >3 months.

Methods: A total of 110 men with clinical BPH were enrolled. There were 17 and 93 subjects with a prostate volume (PV) <30 and ≥30 mL, respectively. All subjects had been treated with α-blocker therapy for >3 months. Subjective and objective clinical variables were assessed using the total International Prostate Symptom Score (IPSS-T), IPSS quality of life (IPSS-QoL), IPSS voiding subscore (IPSS-V), IPSS storage subscore (IPSS-S), overactive bladder symptom score (OABSS), PV, prostate specific antigen (PSA) level, post-void residual (PVR), and maximum flow rate (Qmax). These variables were assessed at baseline and every 3 months for 1 year.

Results: In the small prostate group, IPSS-T and IPSS-V showed improvements from baseline at 6 and 9 months, storage subscore at 6 months, and OABSS at 3 months, but no sustained improvements were observed. During the study period, only the IPSS QoL scores did not show any improvement. Conversly, dutasteride was significantly effective at improving IPSS-T, IPSS-V, IPSS-S, and IPSS-QoL scores throughout the study period in the large prostate BPH group. PSA levels and PV significantly decreased in both groups throughout the study.

Conclusions: Benign prostatic hyperplasia in LUTS patients with small prostates did not show a sustainable benefit from the addition of dutasteride to α-blocker therapy.