Doctors Aware of Tylenol-Related Liver Risk - but Is the Public?

Contact: Kara Gavin, [email protected]

Valerie Gliem, [email protected], 734-764-2220

Embargoed for release Monday, June 18

Physicians aware of Tylenol-related liver damage risk, study finds - but is the general public getting the message?

ANN ARBOR, MI - The message that a common pain reliever can have uncommonly bad effects on the liver under certain conditions seems to have reached most physicians, a new study finds. Now, the challenge lies in getting the word out to their patients and the public.

The newly published study surveyed physicians to assess how well they understand the potentially liver-damaging effects of acetaminophen, commonly sold as Tylenol or as an ingredient in other medications. The results are published in this month's Journal of Clinical Outcomes Management by researchers from the University of Michigan Health System and School of Public Health.

Acetaminophen can lead to potentially fatal liver damage if taken in large doses - either intentionally in a suicide attempt or unintentionally in a prolonged attempt to quell pain - or if taken in conjunction with alcohol, certain other medications or fasting, or by people with existing liver problems. Intentional overdoses are the most common cause of such liver problems, but other causes are gaining notice.

The survey also looked at physicians' understanding of how to treat acetaminophen-related liver problems, their knowledge about how common such problems are, and their attitudes toward recommending liver transplants for those whose livers had been damaged by acetaminophen.

"It appears that most doctors' knowledge is good, with more than 95 percent of them aware of certain risk factors, though there's still room for improvement," says Robert Fontana, M.D., assistant professor of internal medicine at UMHS and senior author of the report. "We should encourage physicians to talk with their patients about all the risk factors, while at the same time, finding more ways to educate the public about this avoidable risk."

While acetaminophen products are safe for most people when used as directed, its toxic effect on the liver can be dramatic under certain conditions. The drug can hamper the liver, or even cause it to fail, when taken in large doses or in conjunction with alcohol. Those who are fasting, and those with cirrhosis, can also suffer the effects at excessive doses. Required warning labels on many packages tell of the potential alcohol-related risk, but some organizations and scientists are calling for even stronger warnings and more public education.

Since physicians are often important educators on health risks, especially for those whose risk is heightened, the U-M team set out to test the knowledge of a sampling of primary care physicians and gastroenterology specialists.

The 28-question survey was mailed to 1,180 randomly selected Michigan physicians in 1999 and 2000, with 397 returning a response. The survey included questions on risk-factor knowledge, knowledge about the safety of acetaminophen and painkillers like ibuprofen (Advil) known as NSAIDs or non-steroidal anti-inflammatory drugs, and attitudes toward liver transplantation for those who had acetaminophen-related liver failure.

Overall, 96 percent of the physicians knew that people who drink more than three alcoholic drinks a day and take acetaminophen are at a higher risk for liver toxicity. The same percentage knew that the total dose of acetaminophen taking in a certain time period can also raise liver risk - for instance, exceeding the recommended 24-hour dose on a bottle of extra-strength painkiller.

And nearly 95 percent knew that those with cirrhosis of the liver have an increased risk from the drug, though 38 percent knew that acetaminophen is preferred over NSAIDS for such patients.

Meanwhile, despite recent evidence suggesting that taking the painkiller during prolonged fasting can have an effect, only about 60 percent of physicians surveyed knew of these issues.

The physicians showed variation in their knowledge about the difference in the risks posed by acetaminophen and NSAIDs. For example, only 61 percent knew that more people die each year from the toxic effects of NSAIDs than die from liver toxicity caused by acetaminophen. And just under half knew that most cases of liver toxicity from acetaminophen result from intentional overdoses.

As might be expected, more gastroenterologists than primary care physicians had handled a case of acetaminophen-related liver toxicity in the past year. And slightly more gastroenterologists knew that N-acetylcysteine could be used to treat it, even after more than 12 hours had passed since the last dose of acetaminophen.

But overall, the primary care physicians showed an impressive knowledge of the issue surrounding the drug - suggesting that recent research and public attention has influenced their awareness.

Now, Fontana and his colleagues say, the next frontier for decreasing incidence of the drug's harmful effects is surveying and educating the general public.

Besides Fontana, the study's authors are Leonard Quallich, M.D., and Thomas Shehab, M.D., gastroenterology fellows at UMHS, and J. Winchester Brown, Ph.D., of the U-M School of Public Health.

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