This medication is used to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. This product contains 2 medications: telmisartan and hydrochlorothiazide. Telmisartan belongs to a class of drugs called angiotensin receptor blockers (ARBs). It works by relaxing blood vessels so blood can flow more easily. Hydrochlorothiazide is a "water pill" (diuretic). It increases the amount of urine you make, especially when you first start the medication. It also helps to relax the blood vessels so that blood can flow more easily. These medications are used together when 1 drug alone is not controlling your blood pressure. Your doctor may direct you to start taking the individual medications first, and then switch you over to this combination product if this is the best dose combination for you.