By Steven Lome
Mechanism of action
Angiotensin receptor blockers (ARBs) are a class of oral medications that act primarily through blockade of the angiotensin receptor. The effects of angiotensin include vasoconstriction and stimulation of aldosterone production. Inhibiting angiotensin receptors will decrease blood pressure through vasodilation and blockade of aldosterone production which normally acts to retain sodium and water.
Angiotensin receptor blockers are used to treat hypertension, systolic congestive heart failure and as nephroprotection in diabetic nephropathy. They are also used during acute myocardial infarction and left ventricular systolic dysfunction without heart failure. Their most common use is when an ACE inhibitor is not able to be tolerated due to cough.
Valsartan, losartan, candesartan, olmesartan, telmesartan, irbesartan
Angioedema is a life-threatening reaction. This is less common with angiotensin receptor blockers than with ACE inhibitors.
A rash is common with angiotensin receptor blockers.
Hypotension can occur causing dizziness and weakness.
Hyperkalemia can occur due to the aldosterone inhibition.
Renal failure can occur due to efferent arteriolar vasodilation.
Angiotensin receptor blockers can dramatically decrease renal function when bilateral renal artery stenosis is present.
The dose of angiotensin receptor blocker needs to be slowly up-titrated to a goal dose in patients with systolic congestive heart failure.