[Drug therapy of benign prostatic hyperplasia syndrome with alpha 1-receptor blockers. Basic principles and clinical results].

This article reviews the structure and function of the sympathetic nervous system controlling the myogenic tone of the bladder outlet. Therefore, the sympathetic nervous system is partially responsible for urinary outflow resistance. The alpha 1-adrenoceptor antagonists alfuzosin, doxazosin, tamsulosin, or terazosin are able to reduce bladder outflow resistance, which leads to significant relief of LUTS (20-65%) and improvement of urinary flow (1-4.3 ml/s) in patients with symptomatic BPH. Alpha 1-blocker treatment works irrespective of the severity of symptoms, degree of subvesical obstruction, or prostate size. A significant reduction of residual urine was observed only occasionally, but at least alfuzosin is able to reduce the incidence of acute urinary retention. This article presents the results of 39 randomized, placebo-controlled trials with 14,924 patients as well as trials with alpha 1-blockers and plant extracts or finasteride. The results of these trials indicate that all alpha 1-blockers are equally effective. However, tolerability of alfuzosin or tamsulosin is superior to doxazosin or terazosin. Furthermore, treatment of hypertension with doxazosin or terazosin is no longer recommended due to the increased frequency of cardiovascular side effects seen in the ALLHAT Study. As alpha 1-blockers can relieve symptoms and improve urinary flow more effectively than plant extracts or finasteride, alpha 1-blockers are the treatment of first choice in patients with symptomatic BPH without or with a minor degree of subvesical obstruction.