Co-Diovan is a combination medication containing two active ingredients: valsartan and hydrochlorothiazide. It is used to treat high blood pressure. Valsartan is an angiotensin receptor blocker (ARB) that works by relaxing blood vessels, while hydrochlorothiazide is a diuretic that helps reduce excess fluid in the body. The combination of these two medications can help lower blood pressure more effectively than either drug alone. Co-Diovan 80/12.5mg tablets come in a pack size of 28 tablets, which contains 2 blister packs of 14 tablets each.