Angiotensin II antagonists

Angiotensin II antagonists

Angiotensin II antagonists block the action of angiotensin II at the receptor level. Angiotensin II receptors are G-protein coupled receptors of the Gi or Gq type and transduce the signal via cAMP and DAG/IP3, respectively. The receptor blockade can be competitive or not, depending on the drug in question. By blocking the receptor, vasoconstriction is inhibited, aldosterone is not released, and the effect of aldosterone on the kidneys is reduced, including the reabsorption of sodium and water. Angiotensin II antagonists differ from ACE inhibitors in that they do not influence the bradykinin levels and angiotensin levels are highly elevated.

Angiotensin II antagonists (losartan, candesartan) are not considered a first-choice treatment. Clinicians are recommended to use this class of drugs after a patient has had to discontinue therapy with an ACE inhibitor due to side effects. Adverse effects of angiotensin II antagonists are limited. They are comparable with those of ACE inhibitors, but much milder.

In elderly patients with heart failure, an angiotensin II antagonist might be more effective than an ACE inhibitor with respect to mortality reduction and treatment of symptoms.

1

What is the most common reason to replace ACE-inhibitors with angiotensin II antagonists?

2

The majority of angiotensin receptors are localized in