It is an orally active quinazoline derivative which exhibits selectivity for α1-adrenergic receptors in the lower urinary tract. Blockade of these adrenoreceptors causes relaxation of smooth muscle in the bladder neck and urethra, resulting in improvement in urine flow and a reduction in symptoms of Benign Prostatic Hyperplasia (BPH) and Bladder Outlet Obstruction (BOO). It is used in the treatment of Benign Prostatic Hyperplasia; Primary Bladder Neck Obstruction
