No, Entresto is NOT an ACE Inhibitor
Entresto (sacubitril/valsartan) is an Angiotensin Receptor-Neprilysin Inhibitor (ARNI), not an ACE inhibitor. It is a distinct drug class that combines an angiotensin receptor blocker (ARB) with a neprilysin inhibitor 1, 2.
What Entresto Actually Is
Entresto is composed of two active components 2:
- Valsartan: An angiotensin II receptor blocker (ARB) that blocks the angiotensin receptor
- Sacubitril: A neprilysin inhibitor prodrug that is converted to LBQ657, which inhibits the enzyme neprilysin
The neprilysin enzyme normally degrades natriuretic peptides, bradykinin, adrenomedullin, and other vasoactive peptides. By inhibiting this enzyme while simultaneously blocking the angiotensin receptor, Entresto addresses two pathophysiological mechanisms in heart failure 1.
Critical Safety Distinction from ACE Inhibitors
Entresto must NEVER be given concomitantly with an ACE inhibitor or within 36 hours of the last ACE inhibitor dose 1, 2. This is a contraindication due to the significantly increased risk of angioedema when these medications are combined 1, 3.
When Switching Between Drug Classes:
- ACE inhibitor to ARNI: Require a 36-hour washout period 1, 4, 2
- ARB to ARNI: No washout period required 4
- ARNI to ACE inhibitor: Require a 36-hour washout period 4
Why This Distinction Matters Clinically
The 2022 AHA/ACC/HFSA guidelines clearly distinguish ARNIs as a separate therapeutic class from ACE inhibitors and ARBs 1. For patients with chronic symptomatic HFrEF NYHA class II or III who tolerate an ACE inhibitor or ARB, replacement by an ARNI is recommended to further reduce morbidity and mortality 1, 5.
The PARADIGM-HF trial demonstrated that sacubitril-valsartan significantly reduced the composite endpoint of cardiovascular death or HF hospitalization by 20% relative to the ACE inhibitor enalapril 1. This superior efficacy is attributed to the dual mechanism of action—something an ACE inhibitor alone cannot provide.
Common Pitfall to Avoid:
Do not assume Entresto can be used interchangeably with ACE inhibitors. While both affect the renin-angiotensin system, their mechanisms differ fundamentally, and their contraindications (particularly the 36-hour washout requirement) are critical for patient safety 2.