Tylenol Safety Debated -- Again
Recommended Dose Safe, but Overdose Danger Debatable
July 23, 2004 -- Is acetaminophen -- best known as Tylenol --
safe enough for over-the-counter sales to continue?
Yes, most experts say. But every year, acetaminophen overdose
is linked to 458 deaths from acute liver failure. Acetaminophen poisoning is
implicated in half of all U.S. liver failures.
Yet tens of millions of Americans use Tylenol regularly. The
FDA says the drug's benefits far outweigh its risks. Not so, argues liver
disease expert William M. Lee, MD, professor of internal medicine at the
University of Southwestern Medical Center in Dallas.
"It still must be asked: Is this amount of injury and death
really acceptable for an over-the-counter pain reliever?" Lee writes in the
July issue of Hepatology.
Lee warns that unintentional acetaminophen overdoses are often
taken for several reasons:
- People take several products, unaware that each one contains the maximum
safe dose of acetaminophen.
- People abusing narcotics often don't realize that the drug is paired with
acetaminophen. As their tolerance for the narcotic increases, they take larger
doses -- and get huge doses of acetaminophen.
- People in pain take more and more pain reliever to get relief, far
exceeding the recommended dose.
- Chronic alcoholics are more sensitive to acetaminophen toxicity.
The largest recommended dose of acetaminophen comes in Tylenol
Extra Strength products. The label instructs users to take two 500 mg pills --
a dose of 1 gram. The label warns people not to take more than 4 grams -- eight
pills -- in a single 24 hour period.
Lee notes that most unintentional overdoses occur with 34
grams, taken, on average, over the course of three days.
That's a lot of pills, says Frank A. Anania, MD, director of
hepatology at Emory University School of Medicine in Atlanta.
"Yes, this drug can be dangerous if people take 8 to 10
grams in a day. But that is 16 extra-strength tablets," Anania tells WebMD.
"But even if you take eight pills every day for three days, that's only 12
grams. So that is a lot of Tylenol in these 'unintentional overdoses.' This
brings up the question of whether the safety issue is one that can truly be
addressed by more regulation of this drug."
Acetaminophen Misconceptions Abound
Lee's article is one of two point/counterpoint editorials in
Hepatology. The companion piece is by Barry H. Rumack, emeritus director
of the Rocky Mountain Poison and Drug Center and professor of pediatrics at the
University of Colorado School of Medicine.
Rumack says Lee is working backward, trying to find out why
people are dying of liver failure. Sure, he's finding evidence that sick people
take Tylenol, but that's what sick people tend to do. Studies that look at what
happens when people take acetaminophen, he says, don't raise red flags.