Abstract
The renin-angiotensin-aldosterone system (RAAS) is one of the main regulators of blood pressure, renal hemodynamics, and volume homeostasis in normal physiology, and contributes to the development of renal and cardiovascular (CV) diseases. Therefore, pharmacologic blockade of RAAS constitutes an attractive strategy in preventing the progression of renal and CV diseases. This concept has been supported by clinical trials involving patients with hypertension, diabetic nephropathy, and heart failure, and those after myocardial infarction. The use of angiotensin II receptor blockers (ARBs) in clinical practice has increased over the last decade. Since their introduction in 1995, seven ARBs have been made available, with approved indications for hypertension and some with additional indications beyond blood pressure reduction. Considering that ARBs share a similar mechanism of action and exhibit similar tolerability profiles, it is assumed that a class effect exists and that they can be used interchangeably. However, pharmacologic and dosing differences exist among the various ARBs, and these differences can potentially influence their individual effectiveness. Understanding these differences has important implications when choosing an ARB for any particular condition in an individual patient, such as heart failure, stroke, and CV risk reduction (prevention of myocardial infarction). A review of the literature for existing randomized controlled trials across various ARBs clearly indicates differences within this class of agents. Ongoing clinical trials are evaluating the role of ARBs in the prevention and reduction of CV rates of morbidity and mortality in high-risk patients.