Hyzaar is manufactured by Merck & Co.
(Click Hyzaar Uses for more information on what Hyzaar is used for, including possible off-label uses.)
Hyzaar is a combination of two medicines --
Cozaar® and hydrochlorothiazide. Cozaar is a newer type of
blood pressure medicine known as an angiotensin II receptor blocker, or ARB for short. Cozaar blocks angiotensin II receptors, thus decreasing the effectiveness of a chemical known as angiotensin II, which normally causes blood vessels to narrow (constrict). By blocking the effects of angiotensin II, Cozaar causes blood vessels to relax.
Hydrochlorothiazide is a diuretic, which is commonly referred to as a "water pill." It works by increasing the amount of salt and water the kidneys remove from the blood. This extra salt and water is passed out through the urine. By increasing the amount of water removed from the blood, hydrochlorothiazide causes a decrease in blood volume.
Because of the effect of both Cozaar and hydrochlorothiazide, Hyzaar can
lower blood pressure. Because of its combined effects, Hyzaar causes a greater drop in blood pressure than when either medicine is used alone.