Open-label, 9-month extension study investigating the uro-selective alpha-blocker silodosin in men with LUTS associated with BPH

Objectives: To evaluate the long-term safety (primary objective) and efficacy/impact on quality of life (QoL, secondary objectives) of silodosin 8 mg once daily in men with LUTS/BPH. Patients and Methods: Men who completed the 12-week double-blind study with silodosin 8 mg, tamsulosin 0.4 mg, or placebo were offered to continue with the 9-month open-label study during which all patients received silodosin 8 mg once daily. Safety was assessed by analysing vital signs, electrocardiograms, laboratory tests, and adverse events. Efficacy was evaluated with the International Prostate Symptom Score (IPSS), IPSS voiding and storage sub-scores, IPSS–QoL, and maximum urinary flow rate (Q_max). Results: A total of 500 patients (mean age 66 years) entered the 9-month open-label study. Treatment-emergent adverse events (TEAE) were experienced by 33.4 % patients. Ejaculation dysfunction was the most common TEAE (9.0 %) but led to study discontinuations in only 1.6 % of patients. Dizziness without orthostatic hypotension occurred in 0.8 %. A marked reduction in total IPSS (−2.7 ± 3.8) was documented at the first visit of this extension phase in patients having de novo silodosin compared with lesser improvement in patients previously treated with silodosin (−0.82 ± 4.2) or tamsulosin (−0.83 ± 3.8). Improvements were maintained throughout the open-label phase. QoL also improved, with the greatest improvement in de novo silodosin patients. No relevant changes in Q_max occurred. Conclusions: Long-term treatment with silodosin was safe and efficacious. Abnormal ejaculation was the most common TEAE, but led to treatment discontinuation in only 1.6 % of patients. Orthostatic hypotension was not seen, and only a few patients experienced dizziness.