Predictors of Successful First-line Antimuscarinic Monotherapy in Men With Enlarged Prostate and Predominant Storage Symptoms

Abstract

To identify predictors of successful first-line antimuscarinic monotherapy for patients with enlarged prostate and predominant storage symptoms. Men aged ≥ 50 years with total International Prostate Symptom Score (IPSS-T) ≥ 8, total prostate volume (TPV) ≥ 20 mL, IPSS quality of life (QOL) index ≥ 2, IPSS voiding to storage (IPSS-V/S) subscore ratio ≤ 1, and post-void residual (PVR) ≤ 250 mL were recruited into a prospective open-label study. All men received tolterodine ER (4 mg) daily. Global response assessment (GRA) ≥ 1 after treatment was considered successful treatment and an indication for continued antimuscarinic monotherapy. One hundred ninety-seven men aged 50-89 years (average TPV 44.4 mL) received first-line tolterodine monotherapy. Mean IPSS-T, IPSS storage (IPSS-S) subscore, and QOL improved significantly at 2, 4, and 12 weeks. Average PVR increased significantly; no patient developed acute urinary retention. One hundred thirty-six patients (69.0%) showed improvement (GRA ≥ 1) at both 2 and 4 weeks. Regression analysis showed that IPSS-S (P = .039) and maximum urine flow (Qmax, P = .033) were significant predictors of therapeutic success. Patients with smaller baseline TPV, higher IPSS-S, and higher Qmax had significantly higher treatment success rates. First-line antimuscarinic monotherapy is safe and effective within 12 weeks in selected patients with benign prostatic hyperplasia (BPH) Higher baseline IPSS-S, higher baseline Qmax, and lower TPV were predictors of successful antimuscarinic monotherapy.