What is the mechanism of action for ARBs?

The mechanism of action for Angiotensin II Receptor Blockers (ARBs) involves their ability to selectively block the angiotensin II type 1 (AT1) receptors. By binding to these receptors, ARBs effectively prevent angiotensin II from exerting its vasoconstrictive effects, which include increasing blood pressure and stimulating aldosterone secretion. As a result, the blockade of these receptors leads to vasodilation, decreased peripheral resistance, and reduction in blood pressure.

The choice that ARBs displace angiotensin II from the AT1 receptor directly aligns with their pharmacological purpose—to inhibit the action of angiotensin II at its primary receptor, thus mitigating the effects of the renin-angiotensin-aldosterone system (RAAS). This action contributes to their therapeutic efficacy in treating conditions like hypertension and heart failure.

Understanding this mechanism is crucial for grasping how ARBs function in the cardiovascular system and why they are utilized in specific clinical situations.