"I do see an occasional overdose where people don't read the label of multiple products," he said. "The combination products where they're taking the equivalent of three times the dose, multiple times a day... acetaminophen is a liver toxin, and I have seen people die of liver failure from it."
Liver transplant specialists agreed. "People are frequently pushing the toxic dose limits by taking too much directly and by unknowingly consuming in other products in parallel," noted Dr. Dan Salomon, transplant biologist at the Scripps Research Institute in La Jolla, Calif.
Dr. Jeffrey Punch, chief of the Division of Transplantation at the University of Michigan Transplant Center in Ann Arbor, Mich., said he has seen patients in need of a liver after problems linked to acetaminophen, "especially patients that take over-the-counter acetaminophen as well as a narcotic drug like Vicodin that also includes large amounts of acetaminophen.
"It is made worse if they take too much acetaminophen along with alcohol and/or while fasting," he added.
The report is not the first time that concerns over the potential for acetaminophen overdose have surfaced. In 2002, Dr. Peter Lurie of the consumer advocacy group Public Citizen appeared before the FDA's Nonprescription Drugs Advisory Committee to relay concerns about unintentional overdoses associated with acetaminophen. In November 2005, a study in the journal Hepatology found that the majority of acute liver failure cases in the U.S. were due to acetaminophen poisoning. And more recent research has suggested that these cases may be on the rise.
Worse, O'Brien said, is that because many who take the medicine are already sick, they could be experiencing the side effects of acetaminophen poisoning without knowing it.
"That's the problem because some of the symptoms are like the flu: nausea, vomiting, and abdominal pain," he said. "It's usually fatal over a day or two."
But Punch said that even the new recommendations may not have a great impact on public health.
"I support the measures, but I don't think the change in maximum dosage will have much effect," he said.
Punch said that if there is a take-home message for consumers, it would be the importance of paying attention to dosage recommendations for acetaminophen.
"It is found in cold medicines, in prescription pain relievers, and in [over-the-counter] pain relievers," he said. "People think that OTC drugs are benign, but they can be just as dangerous as prescription drugs if not taken correctly."
As for Benedi, a jury later found in his favor in an $8 million decision against Johnson & Johnson.
"I went through hell, and so did my family, watching me almost die," he said. "People should really be aware of the dangers of taking Tylenol when not eating properly and if they are used to having a beer or two over the weekends."
The Associated Press contributed to this report.