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Why 'Fizzy' Medicines Can Be Bad for Your Blood Pressure

New study suggests use of fast-acting effervescent pain relievers could raise risk of cardiovascular disease

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If you’re cutting back on salt in your diet, you may want to check your medicine cabinet, too.

A new study, appearing in the European Heart Journal, is raising alarm bells over popular fizzy, fast-acting medications with high levels of sodium — including acetaminophen (also known as paracetamol) — that can be prescribed or purchased over the counter for fever and pain relief.

Researchers who reviewed medical records of nearly 300,000 older adults in the United Kingdom found that those who took an effervescent or soluble form of acetaminophen were at greater risk of developing cardiovascular disease (CVD) or dying prematurely within a year than those who took the medication in pill form containing no sodium.

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“Our findings suggest that individuals should avoid unnecessary excessive sodium intake through sodium-containing acetaminophen use,” concluded the study, led by epidemiologist Yuqing Zhang at Massachusetts General Hospital and Harvard Medical School.

As with any health-related concern, it is always advisable to consult your primary care physician to determine what medications or supplements are best for you.​

Just how much sodium is in these medications?

The effervescent and soluble formulations of acetaminophen taken by study participants contained between 390 and 440 milligrams of sodium bicarbonate per tablet, which provides the fizz. For those taking a full dose of the pain killer, that equates to more than 3,000 mg of additional sodium daily, surpassing the American Heart Association’s (AHA) recommendation to consume no more than 2,300 mg a day. Ideally, the AHA suggests limiting sodium to 1,500 mg a day, especially for adults with high blood pressure.

Sodium is also found in other effervescent medications and supplements:

  • A single 5-gram sachet of effervescent antacids may contain about 850 mg of sodium.​
  • Fizzy vitamins may have about 280 mg of sodium per tablet.​
  • Some urinary alkalinizers contain 644 mg of sodium per dose, according to nutritionist Catherine Saxelby at

Alka-Seltzer Original, an effervescent over-the-counter medication familiar to Americans that combines an antacid with aspirin to relieve both heartburn and pain, contains 567 mg of sodium per tablet. Someone taking the recommended maximum of eight tablets every 24 hours would ingest more than 4,500 mg of sodium, nearly double the AHA recommendation.

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The recommended maximum dosage for adults 60 and over is four tablets every 24 hours. Among the fine print on Alka-Seltzer’s packaging are warnings to ask your doctor before use if you have high blood pressure or are on a sodium-restricted diet. Alka-Seltzer, which contains aspirin rather than acetaminophen for pain relief, was not part of the study.​

Effervescent pain relievers gaining popularity

In an editorial accompanying the study, Aletta Schutte, a research professor at the University of New South Wales, and Bruce Neal, executive director of The George Institute for Global Health in Sydney, Australia, note the growing popularity of fizzy medications, pointing to a 2018 study in France that found that 27 percent of those who underwent medical checkups had consumed fizzy tablets in the previous month, almost all without consulting their primary care providers.

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“The direct message from this study is clear — there are likely to be millions of people worldwide taking paracetamol (acetaminophen) on a daily basis in a ‘fast-acting’ effervescent or soluble formulation who are increasing their risks of cardiovascular disease and premature death,” they wrote.

Peter Urban is a contributing writer and editor who focuses on health news. Urban spent two decades working as a correspondent in Washington, D.C., for daily newspapers in Connecticut, Massachusetts, Ohio, California and Arkansas, including a stint as Washington bureau chief for the Las Vegas Review Journal. His freelance work has appeared in Scientific American, Bloomberg Government, and

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