Calcium channel blocker-ARB-thiazide diuretic combinations are primarily used to treat high blood pressure. These medications generally work by combining three different actions: calcium channel blockers relax your blood vessels, angiotensin II receptor blockers (ARBs) help prevent blood vessels from narrowing, and thiazide diuretics help your body get rid of extra salt and water. These combinations are available in oral forms. Examples include amlodipine / olmesartan / hydrochlorothiazide (Tribenzor) and amlodipine / valsartan / hydrochlorothiazide (Exforge HCT).