α1-Blockers in Men with Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Obstruction: Is Silodosin Different?

Abstract

Available α1-blockers (ABs) have different profiles of receptor selectivity. Silodosin exhibits the highest selectivity for the α1A adrenergic receptor. This pharmacological feature couples with a singular urodynamic and clinical profile. The magnitude of bladder outlet obstruction improvement in patients receiving silodosin is higher if compared to other ABs. From a clinical point of view, current evidence suggests an advantage in favor of silodosin in terms of nocturia improvement and cardiovascular safety. The incidence of ejaculatory dysfunction with silodosin is higher compared to other Abs.

Pharmacotherapy for Nocturia

“…The main rationale for treatment of nocturia with selective α 1 -adrenoceptor (AR) antagonists is that the drugs have a documented effect in the treatment of LUTS, including nocturia [ 29 ]. However, the precise mechanism behind their effect on nocturia is yet to be elucidated.…”

“…Kim et al [ 31 ] investigated improvement in nocturia and nocturnal polyuria after silodosin administration by using a 3-day frequency–volume chart in a prospective multicenter study and found a significant reduction of nocturnal urine volume at 12 weeks compared to screening ( p = 0.001). Roehrborn et al [ 29 ] not only hypothesized that reduction of nocturnal polyuria combined with improved functional bladder capacity are potential mechanisms of action of α 1 -AR antagonists on nocturia, but also that this effect it is related to α 1 -AR subtype selectivity as none of the individual α 1 -AR antagonists without subtype selectivity has consistently shown a significant reduction in nocturnal voiding episodes [ 33 ]. A multicenter 12-wk trial randomized men to receive silodosin, tamsulosin, or placebo and found that only silodosin significantly reduced nocturia versus placebo ( p = 0.013) and the change from baseline was − 0.9, − 0.8, and − 0.7 for silodosin, tamsulosin, and placebo, respectively [ 34 ].…”

Effect of α1D-adrenoceptor blocker for the reduction of ureteral contractions

“…Reportedly, ureteral smooth muscle α1-ARs are denser than other adrenoceptors, and a homogeneous distribution of different α1-AR subtypes has been noted in the human ureter [ 7 ]. In several clinical reports, α1-AR antagonists, including alfuzosin, doxazosin, tamsulosin, silodosin, and naftopidil, were shown to inhibit ureteral contraction [ 8 9 ]. Based on the findings of a randomized controlled study, α1-AR antagonists can be used to promote the spontaneous excretion of ureteral stones in patients.…”

Optimization of HPLC-FLD Conditions Using Analytical Quality by Design Approach for Quantification of Silodosin in Pharmaceutical Dosage Form

“…It has been proven that SLD has higher selectivity for the dominant subtype of the α1A-adrenergic receptor in prostate tissues and inhibits the contraction of prostate smooth muscle. Therefore, it is widely used clinically in the treatment of BHP (Marks, Gittelman, Hill, Volinn, & Hoel, 2009;Roehrborn, Cruz, & Fusco, 2017;Yoshida et al, 2011). The use of the Analytical Quality by Design (AQbD) approach during the development of a new analytical method is an effective strategy in terms of time and quality (Kurmi, Singh, Bhutani, Singh, & Beg, 2014;Peraman, Bhadraya, & Reddy, 2015).…”