Switching from Entresto to losartan should only be done with a clear plan from your cardiologist, who is managing your heart failure or blood pressure. Both medicines affect the renin-angiotensin system, so taking them together—or stopping one and starting the other incorrectly—can raise the risk of low blood pressure, kidney injury, and high potassium, according to MedlinePlus
Entresto is an angiotensin receptor-neprilysin inhibitor (ARNI) that contains valsartan, an angiotensin II receptor blocker (ARB). Losartan is also an ARB. Because Entresto already contains an ARB component, clinicians generally do not prescribe losartan at the same time as Entresto; the switch from Entresto to Losartan involves stopping Entresto and beginning losartan at an individually chosen dose.
This piece is educational and does not replace personalized advice from your cardiologist, primary-care clinician, pharmacist, or heart-failure team.
Why the Switch From Entresto to Losartan is Needed
Entresto is commonly used in heart failure with reduced ejection fraction (HFrEF) and can also be used for hypertension. It combines sacubitril, which increases protective natriuretic peptides, with valsartan, which blocks angiotensin II receptors.
Losartan is an ARB used for high blood pressure, diabetic kidney disease, and stroke-risk reduction in certain people with left ventricular hypertrophy; it may also be used in selected heart-failure cases.
A clinician may consider changing from Entresto to losartan for reasons such as:
- Cost, insurance coverage, or supply issues.
- Side effects thought to be related to Entresto, such as symptomatic low blood pressure or kidney-function changes.
- A clinical decision that an ARB alone is more appropriate for your current condition.
- Pregnancy planning or pregnancy, because drugs acting on the renin-angiotensin system can seriously harm a fetus.
- A change in overall treatment strategy after careful review of heart function, kidney function, potassium, blood pressure, and symptoms.
Do not assume that losartan is automatically an equivalent replacement. In guideline-directed heart-failure therapy, sacubitril/valsartan is generally preferred over an ARB alone for eligible patients with HFrEF, so the reason for switching from Entresto to Losartan matters.
The Most Important Safety Rule in Switching From Entresto to Losartan
Do not stop Entresto and start losartan on your own. Your prescriber needs to determine whether a switch from Entresto to Losartan is appropriate, select the losartan dose, and plan follow-up blood tests.
Entresto contains valsartan, an ARB, and the FDA labeling specifically advises avoiding Entresto with an ARB. Taking both together can increase the risk of hypotension, syncope, hyperkalemia, and kidney problems.
The often-cited 36-hour washout applies when switching between an ACE inhibitor and Entresto—not simply when switching from Entresto to losartan. The FDA Entresto label says that when switching from an ACE inhibitor to Entresto, at least 36 hours should separate the two medicines because combined ACE-inhibitor and ARNI exposure raises angioedema risk.
For an Entresto to losartan switch, the central rule is different: avoid overlapping the two ARB-containing regimens. Your prescriber will tell you exactly when to take the final Entresto dose and when to begin losartan, based on your kidney function, blood pressure, diuretic use, symptoms, and reason for switching from Entresto to losartan.
What Entresto and Losartan Do
| Feature | Entresto | Losartan |
|---|---|---|
| Drug class | ARNI: sacubitril plus valsartan | ARB |
| Main uses | Heart failure with reduced ejection fraction; high blood pressure | High blood pressure; diabetic kidney disease; stroke-risk reduction in certain patients with left ventricular hypertrophy; sometimes heart failure |
| ARB component | Valsartan | Losartan |
| Major shared risks | Low blood pressure, high potassium, kidney-function changes | Low blood pressure, high potassium, kidney-function changes |
| Key pregnancy concern | Drugs acting on the renin-angiotensin system can harm a foetus | Losartan can cause fetal harm and should be stopped as soon as pregnancy is detected. |
Both medicines reduce the effect of angiotensin II, a hormone that narrows blood vessels and can promote sodium and water retention. That is why they can lower blood pressure and affect kidney perfusion and potassium handling.
Before You Switch From Entresto to Losartan: Prepare With Your Clinician
Before changing treatment from Entresto to Losartan, your clinician will usually review:
- Why you are taking Entresto: heart failure, hypertension, or another indication.
- Your most recent blood pressure readings, including home readings if available.
- Kidney function, typically creatinine/eGFR.
- Serum potassium and, when relevant, sodium.
- Volume status: dehydration, recent vomiting or diarrhea, diuretic changes, or signs of fluid overload.
- Other medicines that affect blood pressure, kidneys, or potassium.
- Pregnancy potential and contraception needs.
- Any history of angioedema, kidney-artery narrowing, or severe kidney disease.
Do not begin the switch during an episode of significant dehydration, uncontrolled vomiting or diarrhea, acute illness, or rapidly worsening heart-failure symptoms unless your clinician specifically directs you to do so. Losartan labeling notes that people with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion may be at particular risk of acute kidney failure with medicines in this class.
Entresto to Losartan: A Practical Switching Plan
The exact plan must come from your prescriber, but a safe process usually includes the following steps.
1. Confirm the reason for switching from Entresto to losartan and target therapy
Ask your clinician:
- “Is losartan the right replacement for me, or is another ARNI/ARB more appropriate?”
- “What losartan dose should I start with?”
- “When should I take my last Entresto dose?”
- “When should I take my first losartan dose?”
- “When should I repeat my kidney and potassium tests?”
- “What blood-pressure or symptom changes mean I should call you?”
Because Entresto already includes valsartan, an ARB, losartan should not be added on top of it. This is according to the Food and Drug Administration and GoodRx
2. Stop Entresto only as directed
In many routine outpatient situations, clinicians stop Entresto and begin losartan at the next scheduled dosing time, but the correct timing depends on the individual situation. Do not use a general internet schedule as a prescription.
Do not abruptly stop Entresto without a replacement plan unless your clinician tells you to do so for a safety reason. Stopping heart-failure treatment without an alternative can leave the underlying condition untreated.
3. Start losartan at the prescribed dose
Losartan is usually taken once daily, though some people take it twice daily depending on the prescription. It can be taken with or without food, and clinicians commonly start at a lower dose and adjust it gradually.
Take it at approximately the same time each day, and do not double a dose if you miss one. If it is nearly time for the next dose, skip the missed dose and resume the normal schedule.
4. Monitor closely after the change
Your clinician may arrange blood tests within about 1 to 2 weeks after the transition, particularly if you have kidney disease, diabetes, prior high potassium, low blood pressure, or recent diuretic changes. Monitoring commonly includes blood pressure, creatinine/eGFR, and potassium.
Keep a simple log of:
- Morning blood pressure and pulse.
- Weight, especially if you have heart failure.
- Dizziness, fainting, fatigue, or reduced urine output.
- Swelling in the legs, abdomen, or lungs; shortness of breath; or new/worsening cough.
- Any new medicines, supplements, or changes in fluid intake.
Precautions During the Transition from Entresto to Losartan
Low blood pressure and dizziness
Losartan can cause dizziness, lightheadedness, and fainting, especially when standing up quickly. This may be more noticeable after switching Entresto to Losartan because your body is adjusting to a different regimen and because diuretics or other blood-pressure medicines may still be on board.
Practical precautions:
- Rise slowly from lying or sitting.
- Sit or lie down if you feel faint.
- Avoid driving or hazardous activities until you know how the new regimen affects you.
- Do not skip meals or become dehydrated without discussing it with your clinician.
- Ask before changing diuretic doses; both under-treatment and over-treatment can be risky in heart failure.
Kidney function and dehydration
Illnesses that cause vomiting, diarrhea, fever, or poor fluid intake can lower blood pressure and reduce kidney perfusion. The losartan label specifically identifies diarrhea, vomiting, inadequate fluid intake, and heavy sweating as situations that can lower blood pressure and contribute to lightheadedness or fainting.
Contact your clinician promptly if you develop persistent vomiting, diarrhea, marked reduced urine output, or cannot keep fluids down. They may advise temporarily holding the medicine or adjusting other treatment, but that decision should be individualized.
Potassium and salt substitutes
Both Entresto and losartan can raise serum potassium. The losartan labeling advises periodic potassium monitoring and states that dose reduction or discontinuation may be needed when hyperkalemia occurs.
Avoid starting potassium supplements, potassium-based salt substitutes, or significant dietary potassium changes without checking with your clinician. This is particularly important if you also take:
- Spironolactone or eplerenone.
- Trimethoprim-sulfamethoxazole.
- Potassium supplements.
- Other medicines known to raise potassium.
NSAIDs and kidney risk
Nonsteroidal anti-inflammatory drugs—including ibuprofen, naproxen, and high-dose aspirin used as a pain reliever—can worsen kidney function and blunt the benefit of blood-pressure medicines. MedlinePlus specifically identifies NSAIDs and potassium supplements as products that may interact with losartan.
Ask your pharmacist before using an NSAID, particularly if you have heart failure, chronic kidney disease, dehydration, or diabetes.
Alcohol
Limit alcohol while taking losartan, since it can increase the risk of side effects such as dizziness or low blood pressure.
Warning Signs That You Need Urgent Care
Seek urgent medical care or call emergency services for:
- Trouble breathing, wheezing, or throat tightness.
- Swelling of the lips, tongue, face, throat, or neck.
- Fainting, severe dizziness, or inability to stay awake.
- Chest pain.
- Markedly reduced urine output.
- Severe or persistent vomiting or diarrhea with weakness.
Losartan can rarely cause angioedema—swelling that may involve the face, throat, tongue, lips, or airway. The MedlinePlus losartan information lists facial, throat, tongue, lip, eye, hand, foot, ankle, or leg swelling, hoarseness, and difficulty breathing or swallowing as symptoms that require immediate medical attention.
Although angioedema is more strongly associated with ACE inhibitors and ARNI therapy, any new airway-related swelling during a medication transition warrants urgent assessment.
Pregnancy and Breastfeeding
Losartan must not be used during pregnancy. The FDA labeling says to discontinue losartan as soon as pregnancy is detected because renin-angiotensin-system drugs can cause fetal injury or death, particularly in the second and third trimesters.
If there is any possibility of pregnancy, discuss contraception and a pregnancy-safe blood-pressure plan with your clinician before changing medicines. Do not stop a prescribed heart-failure medicine on your own because of a possible pregnancy; contact your prescriber urgently for an individualized plan.
Common Questions
Is there a required washout period from Entresto to Losartan?
No universal 36-hour washout applies to switching from Entresto to losartan. The 36-hour rule is specific to switching between an ACE inhibitor and Entresto because of angioedema risk.
However, because Entresto contains valsartan, you should not take losartan while still taking Entresto unless your prescriber explicitly instructs otherwise. The safe timing is determined by your prescriber and should prevent meaningful overlap of two ARB-containing treatments.
Can I switch back to Entresto later?
Possibly, but only if your clinician believes it is appropriate. If you later switch from an ACE inhibitor to Entresto, the 36-hour washout is mandatory. If you are switching from losartan to Entresto, ACC guidance states that patients already on an ARB can generally be transitioned directly to ARNI, with dosing and monitoring individualized.
Entresto to Losartan: Will Losartan work as well as Entresto for heart failure?
It depends on the clinical situation. For many eligible people with HFrEF, sacubitril/valsartan is guideline-preferred because it provides both neprilysin inhibition and ARB activity. Losartan may still be appropriate when Entresto is not tolerated, is unavailable, or is otherwise unsuitable—but that decision should be made by the treating clinician.
What if I feel worse after switching from Entresto to Losartan?
Call your prescriber promptly for new or worsening shortness of breath, swelling, weight gain, fainting, very low blood pressure, reduced urine, or persistent dizziness. Do not simply resume Entresto on your own, double losartan, or stop other heart-failure medicines without advice.
Key Takeaways
- Never overlap Entresto and losartan unless a clinician specifically directs it; Entresto already contains the ARB valsartan.
- Follow the exact stop/start instructions provided by your prescriber or pharmacist.
- Do not apply the 36-hour ACE-inhibitor washout rule to a switch from Entresto to losartan; that rule concerns ACE inhibitors and Entresto.
- Monitor blood pressure, kidney function, and potassium after the change, especially if you have kidney disease, diabetes, low blood pressure, or take diuretics.
- Avoid potassium supplements, potassium salt substitutes, and NSAIDs unless your clinician says they are safe.
- Seek urgent care for airway swelling, breathing difficulty, fainting, chest pain, or severely reduced urine output.
A safe switch from Entresto to Losartan is not merely replacing one tablet with another. It is a coordinated medication change that protects your blood pressure, kidneys, potassium level, and heart-failure control while ensuring that you are not left without appropriate treatment.