Atrial natriuretic peptide
Endogenous cardiac peptide hormone. Not FDA-approved; investigational.
What it is
Atrial natriuretic peptide (ANP, also called atrial natriuretic factor or ANF) is a 28-amino-acid peptide hormone produced primarily by atrial cardiomyocytes in response to atrial wall stretch. It is part of the natriuretic peptide family that also includes BNP (brain natriuretic peptide, despite the name primarily produced in cardiac tissue), CNP (C-type natriuretic peptide, primarily endothelial), and others.
ANP was discovered in the early 1980s and represented a paradigm shift in cardiovascular biology — recognition that the heart functions as an endocrine organ producing peptide hormones with significant cardiovascular and renal effects. A synthetic version (carperitide) is approved in Japan for acute decompensated heart failure but has not received FDA approval in the US; ANP is not FDA-approved for any use in the United States.
Mechanism of action
Proposed mechanisms come from laboratory, animal, and human physiology research. ANP acts through natriuretic peptide receptor A (NPR-A), and has been reported to produce:
- Vasodilation: reduced vascular tone in arterial and venous beds
- Diuresis and natriuresis: increased sodium and water excretion through renal effects
- Suppression of the renin-angiotensin-aldosterone system
- Modulation of sympathetic nervous system tone
- Anti-fibrotic effects in cardiac and vascular tissue in animal models
Clinical evidence
ANP and related natriuretic peptides have been studied in heart failure. Recombinant BNP (Natrecor) was FDA-approved for acute decompensated heart failure, but its use has declined. ANP itself (carperitide) is used in Japan for similar indications; studies conducted outside the US have not been evaluated by the FDA. Outpatient or chronic use of natriuretic peptides has not been established, and well-controlled trials establishing the effectiveness and safety of ANP in the US are lacking.
Why we don’t prescribe it at The Tide
The Tide does not prescribe atrial natriuretic peptide. Where it has been used, its applications have been in acute hospital cardiology settings (acute decompensated heart failure) with intensive monitoring. The Tide does not provide acute cardiac care.
Side effects and contraindications
Hypotension, sometimes severe, is the most significant reported risk. Renal effects can be problematic in people with kidney impairment. Long-term effects are unknown.