Study: Too Much Pain Relief Could Hurt You

Nov. 30 2005 —, 2005 -- A new study shows that people who accidentally ingest too much of the drug acetaminophen, the active ingredient in Tylenol, may suffer liver failure. In fact, acetaminophen is the No. 1 cause of acute liver failure.

The six-year study, which will appear in the December issue of Hepatology, found that acetaminophen has become the most common cause of acute liver failure in the United States, and the problem may be growing. Many people overdose after they take multiple medications containing the drug, ABC News medical editor Dr. Tim Johnson said.

The study's participants all took medication to relieve pain. The danger lies in the fact that many patients simply do not know what is in their prescription and over-the-counter drugs, Johnson said.

Researchers reviewed 662 consecutive cases of liver failure between 1998 and 2003. They found that 275 of the cases were attributable to Tylenol poisoning. The rate increased from 28 percent in 1998 to 51 percent in 2003. The overwhelming majority of the poisonings occurred in patients who were female and white. Seventy-four patients died of liver failure and 23 required transplants.

The tricky thing is that the amount of the drug that each person can tolerate depends on individual body composition. Weight is often a factor, he said.

"Read the label and take the recommended dosage," Johnson said. "There are a number of drugs out there that contain acetaminophen: Tylenol, Excedrin, Vicodin and Percocet are some of the best known." Tylenol is one of the most popular painkillers in the United States.

The number of people who suffer from this problem is small in comparison to the number who take acetaminophen every day, Johnson said.

"Talk to your physician about how prescription drugs you're taking might interact with over-the-counter drugs you might take," he said.