Is There a Role for alpha-Blockers for the Treatment of Voiding Dysfunction Unrelated to Benign Prostatic Hyperplasia?

alpha-Adrenoreceptor antagonists have become the primary medical treatment for lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). It was presumed that the primary mechanism by which alpha-blockers reduced lower urinary tract symptoms (LUTS) was by relaxation of smooth muscle in the prostate through a sympathetic response. Reduction of outlet resistance leads to changes in bladder function, thus improving both storage and voiding symptoms. However, it was observed that many patients with BPH-associated LUTS had significant improvement in storage symptoms without subjective or objective improvement in voiding. Storage symptoms associated with detrusor overactivity (frequency, urgency, and urge incontinence) are typically thought of as being parasympathetically mediated, and therefore anticholinergic medications have been the mainstay of pharmacological treatment, but recent work has suggested that several nonparasympathetic-mediated mechanisms may cause detrusor overactivity. Because alpha receptors appear to play a role in lower urinary tract function at multiple sites and levels, alpha-blockers could be used to treat voiding dysfunction not related to BPH. In addition, these nonprostate effects should be gender-independent, making the use of alpha-blockers plausible in women with specific types of voiding dysfunction.