ANGIOTENSIN- RECEPTOR BLOCKERS
The renin-angiotensin-aldosterone system (RAAS) is an important regulator of blood pressure,
blood volume, and fluid and electrolyte levels.
Angiotensin II and aldosterone both influence the effects of the RAAS and cause pathologic
changes in heart and blood vessel tissues.
Angiotensin II is a potent vasoconstrictor and stimulates aldosterone release; both of these
actions increase blood pressure.
Angiotensin-receptor blockers (ARBs) prevent angiotensin II from binding with target
receptors, thereby blocking the actions of angiotensin II.
By blocking angiotensin II actions, ARBs help to dilate veins and arterioles, prevent
remodeling and hypertrophy of heart and blood vessel tissues, and decrease aldosterone release
to lower blood pressure.
Unlike ACE inhibitors, ARBs do not inhibit kinase II and increase levels of bradykinin in the
lungs, so the cough which is a common side effect of ACE inhibitors does not occur with ARBs.
Other side effects of ARBs, such as angioedema, altered renal artery perfusion, and lowered
effectiveness in African-Americans, are similar to those of ACE inhibitors.
What are the main actions on arteries by ARBs?
Vasodilation and increased peripheral vascular resistance
Vasodilation and decreased peripheral vascularresistance
Vasoconstriction and increased peripheral vascular resistance
Vasoconstriction and decreased peripheral vascular resistance
ARBs help prevent which action?
Release of sodium
Release of bradykinin
Release of aldosterone
Absorption of aldosterone
What effect do ARBs have on the excretion ofsodium and water?
Increase excretion of sodium and water
Decrease excretion of sodium and water
Increase excretion ofsodium and decrease excretion of water
Decrease excretion ofsodium and increase excretion of water
• When caring for patients taking ARBs, the nurse should obtain baseline blood pressure
and regularly monitor blood pressure throughout therapy. The target blood pressure is
140/90 mm Hg or lower in most patients and 130/80 mm Hg in patients with diabetes.
• Patients should report shortness of breath, dizziness, and unusual fatigue immediately.
• Patients with heart failure should be monitored for a decrease in symptoms.
• Patients with diabetic nephropathy should be monitored for proteinuria and alterations in
GFR.
• ARBs are contraindicated in patients with a known drug allergy to ARBs. Patients with a
history of angioedema when taking ACE inhibitors should not take ARBs, even though
the risk of angioedema is lower with ARBs. Patients who develop a wheal and flare rash
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