These drugs block the effects of angiotensin, a chemical that causes the arteries to become narrow. Angiotensin needs a receptor- like a chemical "slot" to fit into or bind with- in order to constrict the blood vessel. ARBs block the receptors so the angiotensin fails to constrict the blood vessel. This means blood vessels stay open and blood pressure is reduced.
Beta blockers decrease the effect of adrenaline on the cardiovascular system, slow the heart rate, and reduce stress on the heart and the arteries. Side effects include worsening shortness of breath if you have chronic obstructive pulmonary disease or asthma; sexual dysfunction; fatigue; depression; and worsening of symptoms if you have peripheral artery disease. Beta-blocker examples include: