What Does Entresto Do?

Entresto is a prescription heart failure medication that combines two active drugs, sacubitril and valsartan, in a single tablet. It works by helping the heart pump more efficiently while also relaxing blood vessels, which reduces the workload on the heart. Doctors prescribe it specifically for adults with chronic heart failure to lower the risk of cardiovascular death and hospitalization.

What Does Entresto Do?

Entresto does two distinct things at the same time. The valsartan component blocks a hormone called angiotensin II, which normally narrows blood vessels and raises blood pressure. The sacubitril component inhibits an enzyme called neprilysin, which breaks down beneficial peptides in the body. By blocking that enzyme, Entresto allows those protective peptides to stay active longer, which helps blood vessels relax and encourages the body to excrete excess sodium and fluid.

Together, these actions reduce the strain on a failing heart. The heart does not have to push against as much resistance, and the body holds onto less fluid, which means less swelling and less shortness of breath for many patients. This combination is sometimes called an ARNI, which stands for angiotensin receptor-neprilysin inhibitor.

How Is Entresto Different From Older Heart Failure Drugs?

Before Entresto, the standard treatment for heart failure with reduced ejection fraction was an ACE inhibitor or an angiotensin receptor blocker (ARB) combined with other medications. Entresto replaces the ACE inhibitor or ARB component, but it is not simply a stronger version of those drugs. The sacubitril piece adds a mechanism that older drugs do not have.

In a major clinical trial, patients taking Entresto had lower rates of cardiovascular death and heart failure hospitalization compared to patients taking a standard ACE inhibitor called enalapril. This trial led to Entresto becoming a preferred option in clinical guidelines for many patients with heart failure with reduced ejection fraction. That means the heart’s pumping ability, measured by a number called ejection fraction, is below a certain threshold.

Entresto is not used for people with heart failure with preserved ejection fraction in most cases. The evidence for that group is less clear, and guidelines generally do not recommend it as a first-line treatment for those patients.

Who Should Take Entresto?

Entresto is approved for adults with chronic heart failure. The strongest evidence supports its use in people with heart failure with reduced ejection fraction, often abbreviated as HFrEF. In this condition, the lower left chamber of the heart does not pump blood out forcefully enough. Ejection fraction measures this — a normal heart pumps out about 55 to 70 percent of the blood in its chamber. Heart failure with reduced ejection fraction is generally defined as an ejection fraction of 40 percent or less.

Doctors may also consider Entresto for some people with mildly reduced ejection fraction, but the evidence is not as strong. The decision depends on the individual patient’s overall health, other medical conditions, and how they have responded to other treatments.

Entresto is not for everyone. People who have had a serious allergic reaction to any ACE inhibitor or ARB should not take it. People with a history of angioedema — a type of severe swelling under the skin — should also avoid it. Pregnant women should not take Entresto because valsartan can cause harm to a developing fetus.

How Is Entresto Started and Dosed?

Entresto is started only after a patient has been off an ACE inhibitor for at least 36 hours. This washout period is critical because combining Entresto with an ACE inhibitor can cause dangerous swelling in the face, lips, tongue, or throat, a condition called angioedema. This reaction can block the airway and is a medical emergency.

The medication comes in three strengths: 24/26 mg, 49/51 mg, and 97/103 mg. The numbers refer to the amount of sacubitril and valsartan in each tablet. Doctors usually start patients at a lower dose and increase it gradually based on blood pressure and how well the patient tolerates the medication. The target dose for most patients is the highest strength, taken twice daily.

Blood pressure is monitored closely when starting Entresto. Because the drug relaxes blood vessels, it can cause low blood pressure, especially in the first few weeks. Patients who feel dizzy or lightheaded should tell their doctor rather than stopping the medication on their own.

What Are the Common Side Effects?

The most common side effects of Entresto include low blood pressure, high potassium levels, reduced kidney function, and cough. The cough is less common with Entresto than with ACE inhibitors, which is one reason some patients prefer it. However, it can still occur.

Kidney function and potassium levels are checked with blood tests before starting the medication and periodically after that. High potassium, a condition called hyperkalemia, can cause dangerous heart rhythm problems if it becomes severe. Patients taking potassium supplements or other medications that raise potassium should be monitored closely.

Angioedema is a rare but serious side effect. It causes sudden swelling, usually around the eyes, lips, or throat. If this happens, patients need emergency medical care immediately. The risk is higher in people of African descent, and doctors take this into account when prescribing.

Can Entresto Be Taken With Other Heart Medications?

Yes. Most patients with heart failure take several medications at the same time. Entresto is typically combined with beta-blockers, mineralocorticoid receptor antagonists, and diuretics. These medications work through different mechanisms, and together they address multiple aspects of heart failure.

Diuretics, sometimes called water pills, help remove excess fluid. Patients taking diuretics along with Entresto may need their diuretic dose adjusted, because Entresto itself promotes fluid loss. Doctors often watch for signs of dehydration or low blood pressure when combining these medications.

Certain pain medications called NSAIDs — such as ibuprofen or naproxen — can reduce kidney function and should be used with caution in people taking Entresto. Patients should discuss all over-the-counter medications with their doctor before taking them.

What Happens If You Miss a Dose?

If a patient misses a dose of Entresto, they should take it as soon as they remember, unless it is almost time for the next dose. In that case, they should skip the missed dose and return to their regular schedule. Patients should never take two doses at once to make up for a missed one.

Stopping Entresto suddenly is not recommended. Heart failure symptoms can worsen quickly without the medication. Any decision to stop or change the dose should be made with a doctor’s guidance.

How Long Does It Take to Work?

Some patients notice improvement in symptoms within a few weeks of starting Entresto. Breathing may feel easier, swelling may go down, and energy levels may improve. However, the full benefits of the medication build over time.

The protective effects on the heart continue to develop over months of consistent use. The clinical trial that established Entresto’s benefits followed patients for a median of about 27 months. The medication is designed as a long-term treatment, not a short-term fix. Patients who feel well should continue taking it as prescribed.