UNC study predicts risk for adverse drug reactions

A Triangle-area research team has discovered a metabolic marker in urine that identifies who may develop liver damage from a popular over-the-counter pain reliever.

In a study published in this month's Clinical Pharmacology and Therapeutics, researchers from UNC-Chapel Hill and the Hamner-UNC Institute for Drug Safety Sciences show that urine tests might identify individuals susceptible to damage from acetaminophen, which is sold under the brand name Tylenol, among others. Although it is safe for most patients, acetaminophen can cause serious liver damage in others.

Researchers administered repeated doses of acetaminophen to healthy adult volunteers. About a week later, blood tests found mild and reversible liver damage in some of the patients. Analyzing urine samples taken within one or two days of treatment, researchers discovered that specific patterns of metabolites - byproducts of the body's energy factory - could predict which patients would develop the mild liver damage.

"Severe adverse drug reactions typically occur weeks to months after starting treatment with the offending drug," said Dr. Paul Watkins, professor of medicine at UNC-Chapel Hill and an investigator in the study. "The ability to predict who will develop these reactions has long eluded the research community. This approach, which is called 'metabolomics,' has the potential to make many drugs much safer."