Pain reliever ingredients a puzzle

NORTHWESTERN (US) — A universal icon and warnings about potential liver damage should be included on the labels of over-the-counter medications containing acetaminophen.

Accidental overdose of the drug, the active ingredient in more than 600 medications, is the leading cause of acute liver failure in the U.S.

A new study, published in the American Journal of Preventive Medicine, finds that only 31 percent of participants knew Tylenol contained acetaminophen, while 75 percent of participants knew Bayer contained aspirin and 47 percent knew Motrin contained ibuprofen. In addition, 19 percent knew Aleve contained naproxen sodium and 19 percent knew Advil contained ibuprofen.

“It’s incredibly alarming,” says Michael Wolf, associate professor of medicine at Northwestern University. “People may unintentionally misuse these medicines to a point where they cause severe liver damage.

“It’s easy to exceed the safe limit if people don’t realize how much acetaminophen they are taking. Unlike prescription products, there is no gatekeeper, no one monitoring how you take it.”

Only 41 percent of individuals read ingredients posted on drug labels and so may not realize they may be taking the drug simultaneously in multiple medications, says Jennifer King, lead author of the paper and project leader for medication safety research.

“When you have pain, you aren’t paying attention to what’s in a medicine, you just want relief,” she says. “People think ‘if I can buy it without a prescription, it can’t be harmful.’ They don’t realize exceeding the maximum dose can cause liver damage.”

It may also be difficult to identify drugs in some medicine; for example, acetaminophen is called APAP on prescription medications. “It’s confusing, so even if a person is looking for acetaminophen on the label, she wouldn’t know APAP is the same ingredient in her Tylenol,” King says.

Researchers interviewed 45 individuals in six focus groups to evaluate knowledge of over-the-counter pain relievers, attention to product label information, and literacy level. Forty-four percent of participants, all English speakers, read at or below the sixth-grade level—a low-literacy group at the highest risk for drug misuse.

The study was supported by McNeil Consumer Healthcare, which produces Tylenol. Wolf has worked as a paid consultant to McNeil Consumer Healthcare.

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