Nursing care
Sacubitril-valsartan: washout, angioedema, potassium and renal monitoring
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated October 2026
Short answer
Sacubitril-valsartan combines a neprilysin inhibitor with an angiotensin receptor blocker for heart failure. It must not be given with an ACE inhibitor, and a 36-hour washout is required when switching. Nurses watch for angioedema, symptomatic hypotension, rising potassium and worsening kidney function, and teach patients to report facial swelling and to avoid pregnancy.
Two actions in one tablet explain both benefit and risk
Sacubitril blocks neprilysin, the enzyme that breaks down natriuretic peptides and bradykinin, so more of these vasodilating, sodium-excreting substances remain active. Valsartan blocks angiotensin II receptors, damping the renin-angiotensin-aldosterone system that drives fluid retention and remodelling in heart failure with reduced ejection fraction.
The same chemistry predicts the problems. Extra bradykinin raises angioedema risk, while angiotensin blockade lowers blood pressure, raises potassium and can reduce kidney filtration. The drug replaces an ACE inhibitor or ARB and is used alongside other heart failure treatment such as a beta blocker, so the nurse checks the medication list for duplicate renin-angiotensin blockade.
The 36-hour ACE inhibitor washout and angioedema
Because ACE inhibitors also prevent bradykinin breakdown, combining them with sacubitril sharply increases angioedema risk. The label contraindicates use within 36 hours of the last ACE inhibitor dose and in anyone with previous angioedema from an ACE inhibitor or ARB. Verify the time of the last ACE inhibitor dose before giving the first ARNI dose.
Angioedema has been reported more often in Black patients. Swelling of the lips, tongue, face or throat, or a change in voice, is an airway emergency: hold the drug, assess airway and breathing, call for urgent help and follow the anaphylaxis or angioedema pathway. Teach patients that facial swelling at home needs emergency care, not a wait-and-see approach.
Monitor blood pressure, potassium, kidney function and the right biomarker
Symptomatic hypotension is more common than with an ACE inhibitor, particularly in patients who are volume depleted or taking high-dose diuretics. Check blood pressure before doses and ask about dizziness on standing. Report symptomatic low readings, a rising serum potassium or a rising creatinine to the prescriber rather than simply omitting doses without communication.
Potassium-sparing diuretics and potassium supplements add to hyperkalaemia risk, NSAIDs can worsen kidney function and lithium levels may rise. BNP is broken down by neprilysin, so levels rise on this drug and are less reliable for judging an exacerbation; NT-proBNP is not a neprilysin substrate and is the preferred marker. Recognising this prevents misreading a high BNP.
Hold and report triggers before each dose
Before each dose, review the latest blood pressure, symptoms of dizziness or fainting, serum potassium, creatinine and the medication administration record for any ACE inhibitor. Hold and contact the prescriber for any sign of angioedema, symptomatic hypotension, a newly raised potassium or a sharp creatinine rise, following the parameters written in the order.
Report reduced urine output, vomiting or diarrhoea, which can deplete volume and worsen hypotension and kidney function. When the patient is discharged, make sure the home medicine list no longer includes an ACE inhibitor and that the patient understands this, because an old supply at home is a realistic route to an unsafe combination.
Teaching and an original exam-style scenario
Teach patients to rise slowly, to avoid salt substitutes and potassium supplements unless prescribed, to check with the team before taking anti-inflammatory painkillers, and to keep daily weights. The drug can harm a fetus, so people who could become pregnant need contraception counselling and should report a pregnancy promptly so the drug can be stopped.
In a hypothetical case, a patient took his last lisinopril dose this morning and a new order for sacubitril-valsartan is due tonight. Choices are to give it with food, give it and monitor blood pressure, or hold it and clarify the timing with the prescriber. Holding and clarifying is correct, because the washout has not been completed and angioedema risk is the issue. Giving it with food does nothing for the bradykinin problem, and monitoring blood pressure watches the wrong risk. The safest answer prevents the interaction rather than looking for it afterwards.
Sources and further reading
StatPearls: Sacubitril-Valsartan. Mechanism, 36-hour washout, angioedema, contraindications, monitoring and BNP versus NT-proBNP.
DailyMed: Entresto prescribing information. Fetal toxicity warning, higher angioedema rate in Black patients, hypotension, hyperkalaemia, renal effects and interactions.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our cardiovascular practice questions are the closest set to what this page covers.
Common questions
Why can't sacubitril-valsartan be started the same day an ACE inhibitor is stopped?
Both drugs raise bradykinin levels, which increases angioedema risk. A 36-hour gap after the last ACE inhibitor dose is required before the first ARNI dose.
Is a high BNP a reliable sign of worsening heart failure on this drug?
Less so. Neprilysin normally breaks down BNP, so levels rise with treatment. NT-proBNP is preferred for assessing a suspected exacerbation in these patients.
Which laboratory results should the nurse trend?
Serum potassium and kidney function such as creatinine, alongside blood pressure, weight and symptoms. Report rising potassium or creatinine according to the prescriber's parameters.
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