Mechanism of ActionThrupas Tab, Silodosin is a selective alpha-1 adrenergic receptor antagonist. It works by relaxing the smooth muscle in the prostate and bladder neck, improving urine flow and reducing symptoms of benign prostatic hyperplasia (BPH). Its high selectivity for alpha-1A receptors in the prostate minimizes effects on blood pressure compared to non-selective alpha-blockers.Common Us..