Role of silodosin in patients with LUTS/BPE non responding to medical treatment with tamsulosin: a prospective, open-label, pilot study

OBJECTIVE: Lower urinary tract symptoms (LUTS) are frequently experienced in association with benign prostatic enlargement (BPE). Current guidelines state that alpha-blockers should be considered the first-line therapy of LUTS associated with BPE in most patients. However, in clinical practice treatment efficacy differs among individuals and, therefore, intra-class switch from one alpha-blocker to another, is frequently applied. In particular, switching to silodosin in clinical practice appears an intriguing therapeutic strategy due to the peculiar pharmacological properties of this molecule. This study evaluates the efficacy of silodosin in patients with LUTS associated with BPE who were not-responders to tamsulosin. PATIENTS AND METHODS: This was a prospective, open-label, single-center study. Patients treated with tamsulosin 0.4 mg once daily for BPE/LUTS for at least 12 months and not responding to therapy were switched to silodosin 8 mg once daily. The co-primary endpoints for evaluation of efficacy were the change in IPSS and quality of life (QoL) from the beginning of silodosin therapy to week 8. RESULTS: In total, 96 patients were enrolled. Mean International Prostatic Symptoms Score (IPSS) score at baseline was 20.0 +/- 4.4, and it significantly decreased to 18.6 +/- 4.5 at week 8 (mean change: -1.3 +/- 1.4; 95% CI -1.6 - -1.0; p < 0.03). A decrease was also observed for the two IPSS subscores; in particular, the IPSS sub-score for storage symptoms was significantly reduced at week 8, compared with baseline. A significant improvement in QoL was observed after switching to silodosin, as compared with baseline (-0.8 +/- 1.0; 95% CI -1.0 - -0.6; p < 0.001). CONCLUSIONS: Silodosin improves IPSS symptoms score and QoL in patients with LUTS associated with BPE who were not-responders to tamsulosin therapy.