Which OTC Drugs and Supplements Are Unsafe in Heart Failure?

Many over-the-counter (OTC) medicines, cold remedies, and dietary supplements can interact with congestive heart failure treatments or worsen symptoms. For example, some nonsteroidal anti-inflammatory drugs (NSAIDs) and oral decongestants can promote fluid retention, increase blood pressure, or put extra strain on the heart ^[1][2]. Because heart failure management relies on a careful balance of fluids, electrolytes, and medications, it is important to check with a pharmacist or doctor before starting any new product to avoid unintended complications ^[3].

Why Pain Relievers Like NSAIDs Require Caution

NSAIDs (nonsteroidal anti-inflammatory drugs), such as over-the-counter ibuprofen and naproxen, are commonly used for pain and fever, but they should generally be avoided if you have heart failure ^[4]. These drugs work by blocking the production of prostaglandins—chemicals in the body that normally help keep blood vessels relaxed and support kidney function ^[1].

When prostaglandin production is blocked, it can cause the body to hold onto sodium and water ^[1]. This fluid retention can quickly lead to swelling (edema) and worsen heart failure symptoms ^[1]. NSAIDs can also blunt the effectiveness of your diuretics (water pills) ^[4]. If you take an analgesic-dose NSAID alongside common heart failure medications—like a diuretic and an ACE inhibitor, ARB, or ARNI—you are at a particularly high risk for acute kidney injury (a sudden drop in kidney function), a combination sometimes called the “triple whammy” ^[5]. This risk is even higher if you are dehydrated or have existing kidney impairment ^[5].

Note: If your doctor has prescribed low-dose aspirin for a cardiovascular condition, do not stop taking it without their advice. While aspirin is technically an NSAID, clinician-directed low-dose aspirin is used differently than higher-dose pain relievers.

The Danger of Stimulant Decongestants

When you have a cold or allergies, oral decongestants containing pseudoephedrine or phenylephrine might seem helpful, but they can be problematic for heart failure patients. These drugs are sympathomimetics (stimulants) that constrict blood vessels ^[6]. This increases vascular resistance, forcing your heart to pump against higher pressure ^[6]. As a result, these decongestants may raise your blood pressure or cause heart-rate changes, putting unnecessary stress on the heart ^[2]. Additionally, oral phenylephrine has very limited evidence of actually improving nasal congestion ^[7].

Topical nasal decongestant sprays (like oxymetazoline or xylometazoline) work locally and rapidly improve congestion, but they can still have cardiovascular effects and can cause severe rebound congestion if used longer than the recommended few days ^[8][9]. Always ask a pharmacist for safer alternatives for persistent congestion.

Beware of Combination Cold and Flu Products

One of the biggest hazards in the drugstore aisle is the combination product. Multi-symptom cold, flu, and allergy medicines frequently bundle several active ingredients together ^[10]. A single product might contain an antihistamine, a decongestant, and a pain reliever ^[11].

You must always read the active ingredient labels carefully ^[12]. The goal is to avoid unintentionally taking decongestants, hidden sodium, or duplicate doses of medicines (such as taking acetaminophen for a headache while also drinking a cold syrup that contains acetaminophen) ^[10].

Supplements and Medicines to Review with a Pharmacist

Before buying any new over-the-counter product, consult your pharmacist to check for interactions with your specific heart failure medicines. You do not have to memorize every risk—just show the package to the pharmacist. Pay special attention to:

• Antacids: Some effervescent (fizzing) antacids contain high amounts of sodium, which can trigger fluid retention. Other antacids contain magnesium or aluminum, which can accumulate in your body if you have underlying kidney disease ^[13]. Antacids can also interfere with the absorption of your prescription medicines.
• Laxatives: Frequent use of laxatives, or specific types like sodium-phosphate and magnesium products, can cause diarrhea and significant loss of fluids ^[14]. When combined with prescription diuretics, this can dangerously deplete your electrolytes and worsen kidney function ^[15].
• Potassium Products and Salt Substitutes: While some diuretics lower potassium, other heart failure medications (like ACE inhibitors, ARBs, ARNIs, and spironolactone) cause your body to hold onto potassium ^[16]. Taking OTC potassium supplements or using potassium-based salt substitutes can push your levels too high (hyperkalemia), which can cause dangerous heart rhythms ^[17]. Do not start or stop prescribed potassium without your prescriber’s direction.
• Licorice: Natural black licorice or licorice root supplements contain glycyrrhizin. This compound can cause pseudoaldosteronism, leading to severe potassium loss and increased blood pressure; in rare reported cases, it has even triggered pulmonary edema (fluid in the lungs) and temporary worsening of heart function ^[18].
• Weight-Loss Products: Dietary supplements are regulated differently than prescription drugs and are not pre-approved for safety or effectiveness. Many OTC weight-loss supplements contain sympathomimetics (stimulants) that can increase heart rate and blood pressure, exacerbating the harmful sympathetic nervous system activation already present in heart failure ^[19].

Is Acetaminophen Safe?

Patients are often told to use acetaminophen (Tylenol) as an alternative to NSAIDs for mild pain because it does not cause the same fluid retention or kidney risk ^[20]. However, it is not universally safe.

Acetaminophen must be carefully dosed, and you must count the acetaminophen from every combination product you take to avoid exceeding your daily limit. If you have liver disease or drink alcohol regularly, your safe limit is lower. Additionally, regular or higher-dose use of acetaminophen can interact with the anticoagulant (blood thinner) warfarin. Some large observational studies have observed slightly higher rates of cardiovascular events with acetaminophen compared to no treatment, though the evidence is complex and it is generally considered safer than NSAIDs for heart failure ^[20]. Always ask your doctor for your personal maximum daily dose.

When to Seek Help

If you have taken a new OTC product and develop new or worsening shortness of breath, rapidly increasing swelling or weight, severe dizziness, chest pain, new sustained palpitations, or markedly reduced urination, contact your care team or seek emergency care immediately. Do not adjust your prescribed diuretics or fluid limits on your own to compensate.