Max Acetominophen Dose Linked to Liver Enzyme Rise
Healthy subjects in controlled trial taking 4 grams for four or more days show serum aminotransferase elevations
TUESDAY, July 4 (HealthDay News) -- Patients taking acetaminophen dosages in the upper range of the recommended daily intake can have an increase in liver enzymes, according to a report in the July 5 issue of the Journal of the American Medical Association.
To determine the cause of serum alanine aminotransferase (ALT) elevations observed in a clinical trial of an acetaminophen combination product, Paul B. Watkins, M.D., from the University of North Carolina in Chapel Hill, and colleagues conducted a single-blind, placebo-controlled study in 145 healthy adults randomized to 4 grams daily of acetaminophen alone, or in combination with selected opioids.
While only one of the placebo group participants had an ALT level two times above the upper limit of normal, 31 percent to 44 percent of all groups taking acetaminophen had ALT levels at three times normal or above, irrespective of concomitant opioid treatment. Acetaminophen levels never exceeded therapeutic limits and decreased to undetectable levels even when ALT elevations were still present.
"A history of recurrent acetaminophen ingestion should therefore be sought when evaluating otherwise unexplained elevations in serum aminotransferase observed in clinical practice or during clinical trials," the authors conclude.