Consistent and significant improvement of nighttime voiding frequency (nocturia) with silodosin in men with LUTS suggestive of BPH: pooled analysis of three randomized, placebo-controlled, double-blind phase III studies

Abstract

Nocturia is prevalent and bothersome in men with lower urinary tract symptoms suggestive of BPH (LUTS/BPH). α-Adrenoceptor antagonists without subtype selectivity have inconsistently shown significant effects on nocturia in these patients. We explored the effects of the α1A-adrenoceptor subtype-selective antagonist silodosin on nocturia by analyzing three placebo-controlled registration studies. Responses to question 7 of the IPSS questionnaire were analyzed for the entire study population and patients with ≥ 2 voids/night at baseline. Improvement/worsening rates for nocturia were calculated for once-daily silodosin 8 mg and placebo. Silodosin effects on the mean number of nocturnal voids were compared with placebo, and the number of patients in whom nocturia was reduced to <2 times was calculated. In total, 1,479 men were treated with silodosin or placebo; 1,266 men (85 %) had ≥ 2 voids/night at baseline. Compared to placebo, more men treated with silodosin reported about nocturia improvement (53.4 vs. 42.8 %, p < 0.0001) and fewer patients about worsening (9.0 vs. 14.3 %, p < 0.0001). Silodosin significantly reduced nocturia within each study and pooled cohort compared to placebo (p < 0.001). In men with ≥ 2 nocturnal voids at baseline, 61 and 49 % of patients with silodosin and placebo had reductions of ≥ 1 voids/night, respectively (p = 0.0003), and significantly more patients with silodosin had <2 nocturia episodes at study end compared to placebo (29.3 vs. 19.0 %; p = 0.0002). Although a weak impact on nocturia is already known from α-adrenoceptor antagonists without subtype selectivity, the individual placebo-controlled studies and the pooled data analysis showed that the α1A-adrenoceptor subtype-selective antagonist silodosin consistently and significantly improves nocturia in men with LUTS/BPH.