Acetaminophen, the unpronounceable name for the active ingredient in Tylenol, is the most widely used pain reliever in the United States. But it can destroy the liver in ordinary or near-ordinary doses. That fact is news to many consumers but is old hat to liver specialists who every week treat patients at death’s door from acute liver failure due to acetaminophen.
It has now been documented that acetaminophen is the most common cause in the U.S. of acute liver failure, which can result in death if a liver transplant cannot be done.
The Food and Drug Administration has recognized that acetaminophen poisoning is a public health issue and has slowly taken steps to educate the public to this popular drug’s dangers. In April 2009, the FDA mandated a new warning label, which will say on 500-mg products (Extra Strength Tylenol and its generic equivalents): “Liver warning: This product contains acetaminophen. Severe liver damage may occur if you take more than eight tablets in 24 hours, the maximum daily amount.” It will also warn against using it with other acetaminophen products or with alcohol use of three or more drinks a day. The FDA rejected a request from the Tylenol manufacturer McNeil to water down the warning by removing the word “severe” and adding the word “overdose,” which the agency said could lead consumers to believe they had to greatly exceed the recommended dosage before jeopardizing their livers.
This warning won’t take effect until spring 2010. FDA advisors first recommended such a liver warning in 1977.
In the meantime, an FDA advisory panel will meet in late June to consider other steps intended to make it harder to accidentally cause liver failure from taking too much acetaminophen. A “working group” of advisors has recommended among other things:
• limiting the single adult dose to a maximum of 650 mg, and limiting tablet size to 325 mg (down from the current extra-strength size of 500 mg and single dose of 1000 mg);
• lowering the maximum daily dose for adults from 4000 mg to no greater than 3250 mg (and less than that for chronic alcohol users);
• restricting pediatric liquid formulations to a single mid-strength concentration;
• eliminating acetaminophen from combination products.
You can read the working group’s recommendations at the FDA’s web site here.
In the 1990s, Patrick Malone was one of the first attorneys in the United States to successfully sue the Tylenol manufacturer for hiding the dangers of acetaminophen from doctors and the public. Read about his case of Benedi v. McNeil here. Watch the ABC Prime Time Live segment on this subject by clicking here.