Dangers of acetaminophen (ie: Tylenol)

[Dude]

Date: Tue, 24 Dec 2002 03:07:21 -0000
Subject: [hepcan] INFO: Acetaminophen Overdose Leading Liver Failure Cause !

Acetaminophen Overdose Leading Liver Failure Cause
By Merritt McKinney
Monday December 16

NEW YORK (Reuters Health) - Overdoses of acetaminophen, the active
ingredient in Tylenol and other over-the-counter pain and fever
relievers, are now the leading cause of acute liver failure in the
US, researchers report.

But there is scant evidence that the recommended dose of
acetaminophen can harm the liver, according to the investigators. On
average, people in the study who went into acute liver failure were
taking three times the maximum daily dose of acetaminophen.

Unlike chronic liver failure, which develops gradually, acute liver
failure occurs when a person with no apparent liver disease suddenly
experiences a severe deterioration in liver function. Each year an
estimated 2,000 people in the US go into acute liver failure. During
the past three decades, the leading cause of acute liver failure has
been hepatitis infection, particularly hepatitis B.

That no longer seems to be the case, according to a study of 308
people who experienced acute liver failure from 1998 through 2001 in
the US.

"Drug-induced liver injury makes up more than 50% of cases, and viral
hepatitis appears on the decline as a cause of this acute liver
function," the study's lead author, Dr. William M. Lee of the
University of Texas Southwestern Medical Center in Dallas, told
Reuters Health.

"More importantly," Lee said, "acetaminophen constitutes nearly 40%
of all cases, and this appears to be increasing over the past two
decades."

Acetaminophen overdoses were responsible for 39% of the acute liver
failure cases in the study. Another 13% of cases were thought to be
caused by the effects of other medications. About 12% of cases
stemmed from hepatitis A or B infections, and another 17% were of
uncertain cause. The findings are published in Tuesday's edition of
the journal Annals of Internal Medicine.

The results of the study do not mean that acetaminophen, which is the
most popular over-the-counter pain reliever in the US, is unsafe.
Eighty-three percent of patients who went into liver failure after
taking acetaminophen had exceeded the maximum daily dose. Taking more
than 4,000 milligrams per day (4 g/d) of acetaminophen is not
recommended.

According to Lee, acetaminophen overdose has been the leading cause
of acute liver failure in the UK, where it is known as paracetamol
and is implicated in 73% of cases of acute liver failure. "The study
shows, Lee said, that "US numbers are beginning to approach those in
the UK."

The difference between the US and the UK, however, Lee pointed out,
is that most acetaminophen overdoses are unintentional in the US. In
the UK, cases of acetaminophen overdose are "largely suicidal," the
Texas physician said.

According to the US Food and Drug Administration, common causes of
acetaminophen overdose include inadvertent use of multiple
acetaminophen-containing products at the same time and the
misinformed belief that larger doses will lead to faster relief.

One of the researchers received a Schering Research Fellowship from
the American Association for the Study of Liver Diseases.

SOURCE: Annals of Internal Medicine 2002;137:947-954.