Exforge HCT contains a combination of amlodipine, hydrochlorothiazide and valsartan. Amlodipine is a calcium channel blocker and relaxes blood vessels and improves blood flow. Hydrochlorothiazide is a thiazide diuretic that helps prevent your body from absorbing too much salt, which can cause fluid retention. Valsartan is a angiotensin II receptor antagonist. Valsartan keeps blood vessels from narrowing, which lowers blood pressure and improves blood flow.