March 20, 2023
Acetaminophen is the most commonly used pain reliever in the world, and in the U.S., more than 52 million people use it on a weekly basis. It has a great safety record when consumed in recommended amounts, but it can cause serious and even fatal liver toxicity when recommended doses are exceeded.
Pills that contain both acetaminophen and opiates are a particular concern since pain patients and opioid abusers may be more likely to exceed recommended doses of acetaminophen seeking the opioid effects. To address this risk, the U.S. Food and Drug Administration’s (FDA) mandated in 2011 that manufacturers of these combination products limit the amount of acetaminophen to 325 mg per unit dose and to add a warning about potential liver injury to the packaging.
The Journal of the American Medical Association (JAMA) recently published a study that examined the public health effects of this mandate and concluded that hospitalizations of toxicity due to acetaminophen/opioid combinations went down. However, hospitalization due to toxicity from acetaminophen-alone products increased yearly since 2011.
A commentary co-authored by UNC Eshelman School of Pharmacy’s Paul Watkins, M.D., Howard Q. Ferguson Distinguished Professor in the Division of Pharmacotherapy and Experimental Therapeutics and Marc Ghany, M.D., MHSc, Liver Diseases Branch, National Institutes of Health, titled “Moving the Needle to Reduce Acetaminophen (Paracetamol) Hepatotoxicity” summarized the FDA’s attempts over the years to improve the safety of acetaminophen.
They noted that the apparent rise in acetaminophen liver injuries due to non-opioid combination products was alarming but not easily addressed. For example, an FDA mandate to reduce the amount of acetaminophen in all pills would be difficult to enforce since there are over 600 different health products that contain acetaminophen, and these are produced by many different U.S. and foreign manufacturers.
Watkins and Ghany commented that more needs to be done to encourage consumers to read product labels since acetaminophen is a common additive to over-the-counter pills for a variety of indications. They noted that that an individual’s risk of acetaminophen toxicity is influenced by personal factors such as age, genetics, alcohol consumption and nutrition.
“Acetaminophen reminds us that even very good drugs can be bad for some people, especially when dosing recommendations are exceeded,” said Watkins. “A big problem is that this drug is commonly added to everything from cold medicines to sleep aids and many people are exceeding recommended dosing without even knowing it.”
The co-authors hope the FDA continues to introduce new public health policies to limit acetaminophen liver injuries, but believe the best long-term option is to develop a safer analgesic.