Neprilysin + Angiotensin II receptor (dual)

Class

Angiotensin receptor-neprilysin inhibitor (ARNI)

This mechanism combines two complementary actions in a single molecular strategy: inhibition of neprilysin, an enzyme that breaks down natriuretic peptides, and blockade of the angiotensin II type 1 (AT1) receptor, a key node in the renin-angiotensin-aldosterone system (RAAS). Natriuretic peptides are hormones released by the heart in response to wall stress; they promote sodium excretion, vasodilation, and reduction of cardiac remodeling. When neprilysin is inhibited, these protective peptides persist longer and act more strongly. At the same time, angiotensin II, a hormone that drives vasoconstriction, sodium retention, and fibrosis, is prevented from acting on its receptor. The rationale for pairing both effects rather than using either alone is that neprilysin also degrades angiotensin II itself; blocking neprilysin without also blocking the AT1 receptor would allow angiotensin II levels to rise unopposed, worsening the very processes the therapy aims to counteract. Combining an angiotensin receptor blocker with a neprilysin inhibitor achieves the beneficial peptide effects while neutralizing this offsetting RAAS activation. This dual approach, known as an angiotensin receptor-neprilysin inhibitor (ARNI), is broadly relevant to conditions involving neurohormonal overactivation and volume overload, most notably heart failure, where the heart's declining pumping ability triggers compensatory but ultimately harmful hormonal responses.