ARNI (sacubitril/valsartan): a simple, practical guide

ARNI drugs like sacubitril/valsartan (brand name Entresto) changed how we treat certain kinds of heart failure. They lower the strain on the heart and have been shown to reduce hospital stays and deaths compared with older drugs. If you or someone you care for has heart failure with reduced ejection fraction, this class of medicine is worth understanding.

How ARNI works & who it's for

ARNI combines two actions: one lowers harmful hormones that tighten blood vessels, the other boosts helpful peptides that relax them and remove extra salt and water. Put simply, it helps the heart pump with less pressure and fluid overload. Doctors usually prescribe ARNI for chronic heart failure with reduced ejection fraction (HFrEF). Many patients on ACE inhibitors or ARBs may be switched to ARNI when appropriate because studies showed better outcomes with ARNI.

Common starting doses vary by previous treatment and kidney function. Some people start on a low dose (24/26 mg twice daily) and move up to a target (97/103 mg twice daily) as tolerated. Your provider will tailor dosing to your blood pressure, kidney tests, and other meds.

Safety, monitoring, and buying tips

ARNI can cause low blood pressure, dizziness, high potassium, and rare but serious angioedema (swelling). You should get blood tests for kidney function and potassium before starting and periodically after that. If you take an ACE inhibitor, you must stop it at least 36 hours before starting ARNI to avoid high risk of angioedema.

Don't take ARNI during pregnancy. If you have a history of swelling of the face or throat with ACE inhibitors or ARBs, tell your doctor—ARNI may not be safe for you.

Thinking about buying ARNI online? Buy only from licensed, verified pharmacies that require a prescription. Counterfeit or substandard products are risky. Check licensing, read customer reviews carefully, and avoid sellers offering unusually low prices without prescription checks. If a pharmacy won’t verify your prescription, walk away.

Watch for interactions: ARNI can raise potassium if you also take potassium-sparing diuretics or supplements. Combining with NSAIDs may stress the kidneys. Tell your provider about all prescriptions, OTC meds, and supplements.

Got side effects or lightheadedness after the first doses? Stop driving or operating heavy machinery until you know how the drug affects you, and call your clinician. Small changes in dose or timing can fix many problems, but safety checks are important.

If you want more detail—examples of typical lab monitoring schedules, how to switch from ACE inhibitors safely, or trusted online pharmacy tips—you’ll find helpful articles and buying guides across our site. Ask your healthcare team first; they know your situation and can help you get the right treatment safely.