OSARTAN® 50 mg contains Losartan Potassium, a selective angiotensin II receptor blocker (ARB) used to manage hypertension (high blood pressure) and protect the kidneys in patients with type 2 diabetes and proteinuria. It works by blocking the action of angiotensin II, a chemical in the body that causes blood vessels to tighten, thereby lowering blood pressure and improving blood flow.