Theatel-Trio 40 Tablet is an anti-hypertensive drug that treats high blood pressure (hypertension). It contains Amlodipine, Chlorthalidone, and Telmisartan. Amlodipine is a calcium channel blocker that dilates (widens) blood vessels and increases blood flow. It is used to treat high blood pressure, chest pain (angina), and other conditions caused by coronary artery disease. Chlorthalidone is a diuretic (water pill). It prevents the body from absorbing excess salts that cause fluid retention or build-up. It effectively treats high blood pressure, fluid retention in patients with congestive heart failure, cirrhosis (chronic damage) of the liver, kidney disorders, or edema caused by steroids or estrogen therapy. Telmisartan is an angiotensin II receptor antagonist (angiotensin is a hormone that constricts blood vessels and increases blood pressure). It lowers blood pressure and increases blood flow by preventing the narrowing of blood vessels. It reduces the risk of stroke, heart attac