It is essentially the same as Hyzaar which contains a combination of hydrochlorothiazide
and losartan. Hydrochlorothiazide is a
thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention. Losartan is also in a group of drugs called angiotensin II receptor antagonists. Losartan keeps blood vessels from narrowing, which lowers blood pressure and improves blood flow which is exactly how Diovan works.