Descriptionstelmisartan and hydrochlorothiazide combination is used to treat high blood pressure (hypertension). high blood pressure adds to the workload of the heart and arteries. if it continues for a long time, the heart and arteries may not function properly. this can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. a lower blood pressure can reduce the risk of strokes and heart attacks.telmisartan is an angiotensin ii receptor blocker (arb). it works by blocking a substance in the body that causes the blood vessels to tighten. as a result, telmisartan relaxes the blood vessels. this lowers blood pressure and increases the supply of blood and oxygen to the heart.hydrochlorothiazide is a thiazide diuretic (water pill). it reduces the amount of water in the body by increasing the flow of urine, which helps lower the blood pressure.