Therapeutic effect of α-blockers and antimuscarinics in male lower urinary tract symptoms based on the International Prostate Symptom Score subscore ratio

Abstract

To investigate if the International Prostate Symptom Score (IPSS) voiding-to-storage subscore ratio (IPSS-V/S) can help to guide the treatment for male lower urinary tract symptoms (LUTS). Men aged 40 years or older with a total IPSS (IPSS-T) 8 or more were constitutively enrolled from January 2010 to December 2010. The IPSS voiding (IPSS-V) and storage subscore (IPSS-S) were recorded separately, and the IPSS-V/S was calculated. Patients were divided into two groups according to the baseline IPSS-V/S value. First-line doxazosin (4 mg per day) and tolterodine (4 mg per day) monotherapy were given to patients with IPSS-V/S > 1 and IPSS-V/S ≤ 1, respectively. The IPSS-T, IPSS-V, IPSS-S, quality of life (QoL), maximum flow rate (Qmax), voided volume and postvoid residual (PVR) were measured at 1 month (visit 1) and 3 months (visit 2) after treatment. After medical treatment for 1 month, 89/116 (76.7%) patients receiving tolterodine and 218/279 (78.1%) patients receiving doxazosin reported an improved outcome (global response assessment, GRA ≥ 1 point). The mean IPSS-T, IPSS-S decreased, and QoL improved significantly in both groups. Significant increased Qmax, voided volume, decreased IPSS-V and PVR were noted only in patients receiving doxazosin. There was no significant increase of PVR (from 50.1 to 60.4 ml, p = 0.106), and no patient developed urinary retention after tolterodinie monotherapy for 1 month. However, patients aged more than 70 years had significant association with increased PVR (≥ 50 ml). Initial treatment with doxazosin for patients with IPSS-V/S > 1 and tolterodine for patients with IPSS-V/S ≤ 1 is safe and feasible. Elderly people (≥ 70 years) and patients with Qmax < 10 ml/s are more likely to have increased PVR (≥ 50 ml).