This Popular Med Is "The Most Dangerous OTC Drug," According to Doctors

In cases of mild sickness, your pharmacy often has everything you need to put you back on the path to wellness. But experts warn that convenience can come with consequences: Some over-the-counter (OTC) drugs that many consumers consider safe can cause a range of adverse effects. In particular, one popular medication has been linked to roughly half of all cases of acute liver failure in the U.S.—a fact that's prompting experts to sound the alarm about its safety. Read on to find out which medication doctors say is "the most dangerous OTC drug" in the nation, and how to avoid serious side effects when you take it.

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OTC medications can cause serious health problems.

Though OTC drugs are sold just down the aisle from everyday items like shampoo, cosmetics, and bandages, they can come with an unspoken risk of serious illness. "Self-medication, including both the use of over-the-counter (OTC) drugs and the use of formerly prescribed drugs taken without a current physician's recommendation, is a public health concern," says a 2014 study published in the journal Drug Safety.

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This is the most dangerous OTC drug, according to doctors.

The most dangerous OTC drug, according to various studies and doctors, is one you likely have at home: Tylenol. Generating over a billion dollars in annual sales, Tylenol is one of the most widely sold OTC drugs in the nation. The active ingredient in Tylenol, acetaminophen, is also used in a range of other medications, including many popular decongestants and cough syrups.

However, experts warn that this ubiquitous drug has been linked with just over half of all cases of liver failure in America. "Taking too much acetaminophen… is the most common cause of acute liver failure in the United States," explains the Mayo Clinic. "Acute liver failure can occur after one very large dose of acetaminophen, or after higher than recommended doses every day for several days."

John Brems, MD, a professor of surgery at Loyola University in Chicago who treats patients with acute liver poisoning, recently shared his own warning on the matter. "Acetaminophen is a dangerous drug," he told ABC News, via Drug Watch. "It is probably the most dangerous OTC drug in this country."

Tylenol overdoses may be more common than you think.

While you may have already been aware of Tylenol's risk of adverse effects, you may still be surprised to learn how consequential those risks can be. A 2004 study published in the journal Hepatology reports that acetaminophen-based drugs like Tylenol account for over 100,000 calls to poison centers, 60,000 emergency-room visits, 2,500 longer term hospital stays, and hundreds of deaths in the U.S. each year.

The researchers note that while Tylenol is "heavily marketed for its safety," its risks are in fact plentiful and well-documented. "By enabling self-diagnosis and treatment of minor aches and pains, its benefits are said by the Food and Drug Administration to outweigh its risks," the team wrote. "It still must be asked: Is this amount of injury and death really acceptable for an over-the-counter pain reliever?"

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Doing this puts you at high risk of an adverse reaction.

All medications have the potential to cause harm when they are misused, but certain factors put you at heightened risk of a problem. Experts say your chances of having an adverse reaction to Tylenol increase if you take more than the recommended dosage, mix it with other medications which could cause drug interactions, are allergic to any of its ingredients, or take it with alcohol.

Brems noted that in his experience, mixing Tylenol with alcohol is the most common cause of a life-threatening reaction. "Many of these patients took acetaminophen in addition to alcohol. I end up transplanting three to four patients per year, and two to three die before we can transplant them," he told ABC News.

It's always a good idea to speak with your doctor before you begin any new medical regimen, even if the drugs you plan to take are available without a prescription.

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