Both these drugs treat high blood pressure. However, Diovan can be used in children ages 6 and up as well as adults, while Diovan HCT has not been shown to be safe and effective in children. Another difference: Diovan is also prescribed for heart failure and to increase the odds of long-term survival after a heart attack. Diovan HCT is not approved for these additional conditions.
Valsartan, an active ingredient in both drugs, belongs to a class of drugs called angiotensin receptor blockers (ARBs), which lower blood pressure by relaxing and dilating blood vessels to improve blood flow. Diovan HCT also contains hydrochlorothiazide, a diuretic that lowers blood pressure by helping the body excrete excess water and salt (sodium). Doctors often prescribe Diovan HCT to people whose blood pressure was not reduced enough by taking Diovan alone or hydrochlorothiazide alone.