Prosta-Tab PR 0.4 mg is a prolonged-release tablet containing Tamsulosin Hydrochloride, a selective alpha-1 adrenergic receptor blocker. It is primarily used for the treatment of benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate gland in men. Tamsulosin works by relaxing the smooth muscles in the prostate and bladder neck, allowing for improved urine flow and reducing symptoms such as difficulty urinating, weak stream, and frequent urination (especially at night).