Interfere with the binding of angiotensin II to angiotensin receptors and lower blood pressure without causing cough.
ARBs result in renin-angiotensin – aldosterone system blockade by antagonizing the effect of angiotensin II hormone on angiotensin I receptors.
In patients with congestive heart failure significantly reduces the risk of cardiovascular death or nonfatal myocardial infarction.
Maximal doses are required to reduce albuminuria and slow progression of nephropathy in diabetes.
Risk factors for ACE inhibitors or ARB induced hyperkalemia include renal insufficiency, diabetes, reduce the left ventricle function and advanced age.
For first line treatment of hypertension, ARB˜s work as well as ACE Inhibitors but are safer: with no statistical significant differences in primary cardiovascular outcomes between the two groups, but ARBs had a lower risk of angoedema, cough, acute pancreatitis, and gastrointestinal bleeding.
The use of trimethoprim-sulfamethoxazole in older patients with ace inhibitors or ARB’s is associated with an increased risk of hyperkalemia relative to other antibiotics.
Associated with an incresed risk of new cancer diagnosis vs. placebo: 7.2 vs 6% based on a meta-analysis of 68,402 patients: 1.2% increase in absolue risk for cancer overall.
Meta-analysis suggests increased risk of malignancies (Sipahi I).
In the Randomized Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study this agent (Benicar) was tested at 40 mg a day, compared with placebo in type II diabetics, with one of cardiovascular risk factor, normoalbuminuria , to seek a target blood pressure of less than 130/80 mm of mercury:Olmesartan was associated with delayed onset of microalbuminuria with 8.2% versus 9.8% in the placebo group, the time to onset of microalbuminuria was increased by 23%, fewer nonfatal cardiovascular events 3.6% versus 4.1% but a greater number of fatal cardiovascular events 0.7% versus 0.1% (Haller H et al.).
Candesartan and valsartan compared to placebo reduce morbidity and mortality in congestive heart failure.
In a randomized trial of losartan in heart failure was comparable to the ace inhibitor captopril (Konstam MA et al).
Azilsartan may improve blood pressure control by 8-10% compared with other ARB‘s.
ARBs, specifically Irbesartan, does not reduce cariovascular enents in patients with atrial fibrillation in patients with atrial fibrillation (ACTIVE I Investigators).
ARBs have no effect in preventing atrial fibrillation in patients with intermittent atrial fibrillation(The GISSI-AF Invest a Tors).
Ace inhibitors and angiotensin II receptor blockers reduce hemoglobin levels in several groups of patients at risk for secondary erythrocytosis including patients with heart failure, hemodialysis, or COPD, after cardiac surgery or kidney transplant.
Angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors are equally effective in the treatment of hypertension, but ARBs may be less likely to result in adverse events.
Ace inhibitors and ARB’s are effective treatments for secondary polycythemia related to renal transplant and reactive high-altitude erythrocytosis.
Hemoglobin levels are reduced during the first year of use of ACE inhibitors and to a lesser expense with a ARBs
In patients without heart failure ARBs are as efficacious and safe as ACE inhibitors, with better tolerability.