Senior author Michael Wolf of Northwestern University Feinberg School of Medicine in Chicago says his study found only 31 percent of participants knew Tylenol contained acetaminophen; 75 percent of participants knew Bayer contained aspirin; 47 percent knew Motrin contained ibuprofen; 19 percent knew Aleve contained naproxen sodium and 19 percent knew Advil contained ibuprofen.
"It's incredibly alarming," Wolf says in a statement. "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."
The study, published in the American Journal of Preventive Medicine, finds 41 percent of participants read the ingredients on drug labels.
"When you have pain, you aren't paying attention to what's in a medicine, you just want relief," lead author Jennifer King says in a statement. "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 and people don't understand they may be taking the drug simultaneously in multiple medications."
In addition, acetaminophen is found not only in over-the-counter medications like Tylenol, it is called APAP on prescription medications, King said.