Clinical characteristics of α-blocker responders in men with benign prostatic hyperplasia

Background: Currently, a-blocker is becoming first-line drug therapy for benign prostatic hyperplasia (BPH). Although highly effective results are obtained with this therapy, a difference between the objective and subjective response rates is reported. To prevent unnecessary medical treatment and to predict the alpha-blocker response, we characterized the clinical features of alpha-blocker responders in men with BPH. Methods: Twenty-two men were consecutively enrolled in this study and received tarnsulosin 0.2 mg once daily for 4-6 weeks. The primary measures of efficacy were maximum urinary flow rate (Q(max)) determined from the flow measurements and international prostate symptom score (IPSS). Those with an increase in Q(max) of greater than or equal to30% from baseline and a decrease in IPSS of greater than or equal to25% from baseline were defined as Q(max) responders and IPSS responders, respectively. Clinical findings such as age, pretreatment IPSS and Q(max), serum prostate-specific antigen (PSA), total prostate volume, transition zone (TZ) volume, TZ index and T-2-weighted magnetic resonance image (MRI) of the prostate TZ were compared between responders and non-responders for both criteria. Results: In 17 of 22 (77.2%) patients IPSS improved by :25%. In 9 of 22 (40.9%) patients Q(max) improved by 30%. There were no differences in clinical findings between IPSS responders and non-responders. On the contrary, Q(max) responders showed smaller total prostate and TZ volumes, a smaller TZ index and a lower intensity of the TZ in MRI than Q(max) non-responders. Conclusions: Determination of the prostate volume and MRI findings of the inner prostate gland were useful in predicting Q(max) responders to the a-blocker in men with BPH. In contrast, there were no clinical characteristics of the IPSS responders. IPSS responders without a Q(max) response should be closely followed while continuing the a-blocker therapy for a long duration. Copyright (C) 2002 S, Karger AG, Basel.