alpha-adrenoceptor antagonists in the treatment of benign prostatic hyperplasia

Lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH ) have a significant impact on the lifestyle of older men. Transurethral re section of the prostate (TURP) is the most effective surgical therapy for t his condition but an increasing number of patients are electing conservativ e medical therapy. alpha-Adrenoceptor antagonists and 5 alpha-reductase inhibitors are the 2 c ategories of drug therapy currently available for BPH. Use of alpha-adrenoc eptor antagonists in the treatment of BPH is based on their ability to prev ent the neural stimulation which induces prostate smooth muscle contraction , producing lower urinary tract symptoms. Several studies have demonstrated that alpha-receptors predominate in the prostatic stroma, capsule and blad der neck. Initial work focused on the use of phenoxybenzamine, a nonspecifi c alpha-blocker, in the treatment of BPH. While results were promising, sig nificant adverse effects and concern over potential mutagenicity have resul ted in a lack of use of this medication for this indication. Subsequent att ention was directed towards the short-acting alpha-specific antagonist praz osin. Results conflicted regarding whether an actual sustained improvement in lower urinary tract symptoms could be achieved with this medication, and because of twice daily dosing compliance issues were a drawback. Thus, the mainstay in pharmacological treatment of BPH over the past decade has been 2 once-a-day alpha-specific antagonists, doxazosin and terazosin. Over 75% of all prescriptions written for BPH are for one of these 2 medications. D espite their tremendous success in both decreasing urinary symptoms and inc reasing urinary flow rates. systemic adverse effects can be bothersome. Rec ently, efforts have focused on use of alpha(1A)-urospecific antagonists suc h as tamsulosin and alfuzosin in an attempt to achieve similar clinical res ults as doxazosin and terazosin without systemic adverse effects. Thus far. results are promising, but long term studies must be done to determine whe ther pharmacological uroselectivity is actually clinically relevant.