The diagnosis and treatment of lower urinary tract symptoms due to benign prostatic hyperplasia with α-blockers: focus on silodosin

Clin Drug Investig. 2015 Feb:35 Suppl 1:7-18. doi: 10.1007/s40261-014-0257-3.

Abstract

Lower urinary tract symp toms due to benign prostatic hyperplasia (LUTS/BPH) are common in aging men and can progress to acute urinary retention. Among the classes of agents recommended for patients with moderate to severe symptoms are α-adrenergic receptor (adrenoceptor) antagonists (α-blockers) and 5α-reductase inhibitors (5ARIs). This review provides a brief overview of the diagnosis and management of LUTS/BPH, focusing on the efficacy and tolerability of α-blockers approved for the treatment of LUTS/BPH, with particular emphasis on silodosin, a novel α-blocker. Of the older α1-blockers, alfuzosin, doxazosin and terazosin show little selectivity for the α1-adrenoceptor subtypes, while tamsulosin is moderately and silodosin is highly selective for the α1A subtype in preference to the α1B subtype. Highly selective α1A-receptor antagonists such as silodosin were developed specifically for the treatment of LUTS because non-selective antagonists were associated with cardiovascular adverse effects. Since α1A is predominantly expressed in the prostate, higher selectivity for α1A may account for lower blood pressure-related adverse effects. Silodosin is administered once daily and provides rapid improvements in the signs and symptoms of moderate to severe LUTS/BPH in male patients. As with other α-blockers, silodosin is generally well-tolerated and the most common adverse events seen are abnormal ejaculation, dizziness, headache, diarrhoea, nasal congestion and orthostatic hypotension. Unlike 5ARIs, α-blockers do not impair libido. Given the prevalence of LUTS/BPH and the efficacy and tolerability concerns with existing therapies, silodosin is a welcome addition to the pharmacological options for these patients.

Publication types

  • Review

MeSH terms

  • Adrenergic alpha-1 Receptor Antagonists / therapeutic use*
  • Humans
  • Indoles / therapeutic use*
  • Male
  • Prostatic Hyperplasia / diagnosis*
  • Prostatic Hyperplasia / drug therapy*
  • Prostatic Hyperplasia / physiopathology
  • Urinary Tract / physiopathology*
  • Watchful Waiting

Substances

  • Adrenergic alpha-1 Receptor Antagonists
  • Indoles
  • silodosin