Mechanism of action Eprosartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor found in many tissues (e.g., vascular smooth muscle, adrenal gland). There is also an AT2 receptor found in many tissues but it is not known to be associated with cardiovascular homeostasis. Eprosartan does not exhibit any partial agonist activity at the AT1 receptor. Its affinity for the AT1 receptor is 1,000 times greater than for the AT2 receptor. In vitro binding studies indicate that eprosartan is a reversible, competitive inhibitor of the AT1 receptor. Eprosartan has also been shown to bind to AT1 receptors both presynaptically and synaptically. Its action on presynaptic AT1 receptors results in the inhibition of sympathetically stimulated noradrenaline release. Unlike ACE inhibitors, eprosartan and other ARBs do not interfere with response to bradykinins and substance P