α1-adrenoceptor selectivity and the treatment of benign prostatic hyperplasia and lower urinary tract symptoms

The storage (irritative) and voiding (obstructive) symptoms associated with benign prostatic hyperplasia are generally attributed to prostate enlargement and increased prostatic smooth muscle tone mediated by the prevailing alpha(1)-adrenoceptors in the bladder neck and prostate. This results in obstruction and subsequent secondary changes to the bladder. However, there is growing evidence that many of these symptoms may be due to changes in extraprostatic alpha(1)-adrenoceptors, possibly alpha(1D)-adrenoceptors. Findings from the VA cooperative trial challenge the current theory that the common side effects associated with these agents are due to vascular action of alpha(1)-adrenoceptor blockers.