Alpha adrenergic antagonists for the treatment of symptomatic BPH

Benign prostatic hyperplasia (BPH) describes a benign enlargement of the prostate gland that develops in the aging male population. Approximately 50% of 60-year-old men have histologic evidence of BPH. The clinical manifestations of BPH are related entirely to the obstruction of urinary outflow. Benign prostatic hyperplasia produces obstruction to urinary flow by static and dynamic factors. The dynamic component of infravesical obstruction presumably is mediated by the tone of the prostate smooth muscle. Pharmacologic agents that cause relaxation of the prostate may represent an effective therapeutic approach for symptomatic BPH. Organ bath contractile studies have indicated that the contractile properties of prostate adenoma are mediated by alpha1 adrenoceptors. Ten clinical trials evaluating the efficacy of alpha adrenergic blockers for the treatment of symptomatic BPH have been performed in Europe during the past 11 years. Clinical efficacy was observed in 9 of the 10 clinical trials. Randomized, placebo controlled, multicenter clinical trials are currently in progress in the United States to evaluate the efficacy of alpha blockers for the treatment of BPH. Rationale and the clinical experience of alpha adrenergic blockers for the treatment of symtomatic BPH is reviewed in this article.