Safety alert
date: 11/08/2006
High-dose acetaminophen may pose liver risk
If you take high doses of acetaminophen for even a short time you may risk damaging your liver. Turn to ConsumerReportsHealth.org for information on how to take acetaminophen safely to treat chronic pain.
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A new study
has raised concerns that taking the maximum recommended dosage of acetaminophen (generic, Tylenol) for as little as several days may harm the liver.
Researchers at several universities assigned 145 healthy adults to take either a placebo or the maximum 4,000 milligrams per day of acetaminophen, alone or with an opioid painkiller. Four to 11 days later, more than one-third of those taking acetaminophen, with or without the opioid, developed significantly elevated liver enzymes, a sign of abnormal liver function. That did not occur in the placebo group.
Enzyme levels almost always returned to normal after the drug was stopped, except in one person who wasn’t followed long enough to draw clear conclusions. No participants reported signs of liver damage. McNeil, maker of Tylenol, says unpublished data culled from several studies show a much lower incidence of enzyme elevations at the top dosage.
Acetaminophen at moderate dosages is still the preferred treatment for chronic pain. It’s generally safer than nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (generic, Advil), naproxen (generic, Aleve), and aspirin, which can cause stomach bleeding and ulcers. NSAIDs other than aspirin may also increase heart risk.
The new study underscores the importance of using the lowest effective dose of acetaminophen and of reading labels to avoid simultaneously taking any other medicine that contains that drug. If you need the top dosage for a prolonged period, our medical consultants advise having your physician check your liver enzymes periodically. People who have liver disease or drink alcohol heavily should consult their doctor before taking anything more than an occasional acetaminophen.
has raised concerns that taking the maximum recommended dosage of acetaminophen (generic, Tylenol) for as little as several days may harm the liver.Researchers at several universities assigned 145 healthy adults to take either a placebo or the maximum 4,000 milligrams per day of acetaminophen, alone or with an opioid painkiller. Four to 11 days later, more than one-third of those taking acetaminophen, with or without the opioid, developed significantly elevated liver enzymes, a sign of abnormal liver function. That did not occur in the placebo group.
Enzyme levels almost always returned to normal after the drug was stopped, except in one person who wasn’t followed long enough to draw clear conclusions. No participants reported signs of liver damage. McNeil, maker of Tylenol, says unpublished data culled from several studies show a much lower incidence of enzyme elevations at the top dosage.
Acetaminophen at moderate dosages is still the preferred treatment for chronic pain. It’s generally safer than nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (generic, Advil), naproxen (generic, Aleve), and aspirin, which can cause stomach bleeding and ulcers. NSAIDs other than aspirin may also increase heart risk.
The new study underscores the importance of using the lowest effective dose of acetaminophen and of reading labels to avoid simultaneously taking any other medicine that contains that drug. If you need the top dosage for a prolonged period, our medical consultants advise having your physician check your liver enzymes periodically. People who have liver disease or drink alcohol heavily should consult their doctor before taking anything more than an occasional acetaminophen.
CITATIONS
Watkins PB, et al. “Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily,” Journal of the American Medical Association, July 5, 2006, pp. 87-93.This article first appeared in the November 2006 issue of Consumer Reports on Health.
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