Comparison between angiotensin converting enzyme inhibitors and angiotensin II antagonists

The renin-angiotensin-aldosterone system (RAAS) plays an important role in blood pressure regulation and fluid and electrolyte homeostasis. Angiotensin converting enzyme inhibitors (ACEI) were the first of the RAAS blocking agents to be widely used in the treatment of hypertension and congestive heart failure. Ansotensin II receptor antagonists, another class of pharmacological blockers of the RAAS, have more recently been shown to be safe and useful in hypertension and perhaps also in heart failure. This review deals with the similarities and differences between these two classes of drugs with particular emphasis on the effects of the drugs on the heart, the blood vessels, the kidney (role of the drugs as nephroprotective), the brain, the hormonal profile and finally the potential adverse effects. The place of angiotensin II antagonists in congestive heart failure remains to be more precisely defined.