How do ARBs differ from ACE inhibitors in their function?

Angiotensin II receptor blockers (ARBs) specifically target and block the action of angiotensin II, a potent vasoconstrictor that plays a crucial role in regulating blood pressure. By inhibiting this action, ARBs lead to vasodilation, reduced blood pressure, and decreased workload on the heart. This mechanism is distinct from ACE inhibitors, which prevent the formation of angiotensin II by inhibiting the enzyme that converts angiotensin I to angiotensin II.

While ARBs do promote vasodilation indirectly as a result of blocking angiotensin II, the primary and direct function of these medications is to block angiotensin II at its receptor sites. This specific action differentiates ARBs from medications that might exert vasodilatory effects through other mechanisms.

Additionally, ARBs do not directly promote diuresis nor do they function to lower heart rate, as their primary role is centered around the inhibition of angiotensin II, representing a key distinction from ACE inhibitors and highlighting their unique pharmacological profile in managing hypertension and heart failure.