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, enalapril and hydrochlorothiazide. Enalapril belongs to a class of drugs known as ACE inhibitors. It works by relaxing blood vessels so that blood can flow through the body more easily. Hydrochlorothiazide is a "water pill" (diuretic) and causes your body to get rid of extra salt and water. This effect may increase the amount of urine you make when you first start the medication. It also helps to relax the blood vessels so that blood can flow through the body more easily.