Calcium channel blockers. Calcium channel blockers, also known as calcium antagonists, work by interrupting the movement of calcium into heart and blood vessel tissue. Besides being used to treat high blood pressure, they're also used to treat angina (chest pain) and/or some arrhythmias (abnormal heart rhythms). Beta-blockers. Beta-blockers decrease the heart rate and cardiac output, which lowers blood pressure by blocking the effects of adrenalin.