The danger of acetaminophen

It has long been known that too much acetaminophen can cause liver damage, but the alarming extent of the problem has just been documented. A new study has found that overdosing on acetaminophen, the most widely used nonprescription analgesic, was responsible for 39% of 308 cases of acute liver failure.

Most cases of liver toxicity from acetaminophen reported by the Acute Liver Failure Study Group, a consortium of 17 centers specializing in liver diseases, were accidental and not suicides. Seventy-nine percent of them were women. “We don’t know if this is because women take more acetaminophen-containing drugs than men do, if women’s livers are more vulnerable, or if it’s because they are smaller,” says Dr. William M. Lee, the principal investigator and professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas.

“We were surprised to find that the number of people with liver damage from acetaminophen was three times that of all other prescription drugs,” Lee says. He cautions people to be careful of how much they take and read the labels of all over-the-counter products taken together. Mixing acetaminophen-containing medicines for cough, sleep and pain can add up to a dangerous dose. Most people in this study had taken more than 4,000 milligrams of the drug. The study of cases over a 41-month period was reported in the Dec. 17 Annals of Internal Medicine.

Earlier this year, a preliminary report of this study’s findings prompted a Food and Drug Administration committee to advise that over-the-counter products containing acetaminophen such as Tylenol and other pain relievers and cough-and-cold remedies carry a stronger warning label than they currently do.