The symptoms associated with benign prostatic hyperplasia (BPH) such as urinary frequency, nocturia, weak stream, hesitancy and incomplete emptying are related to two components, anatomical (static) and functional (dynamic). The static component is related to the prostate size. But prostate size alone does not correlate with symptom severity. The dynamic component is a function of the smooth muscle tone in the prostate and its capsule, the bladder neck and the bladder base as well as the prostatic urethra.
The smooth muscle tone is regulated by alpha-adrenergic receptors. Alfuzosin is an orally active quinazoline derivative, peripherally acting antagonist, exhibits selectivity for postsynaptic alpha-1 adrenergic receptors in the lower urinary tract. Blockade of these adrenoceptors can cause smooth muscle in the bladder neck and prostate to relax, resulting in an improvement in urine flow and a reduction in symptoms of BPH.