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Daily Intake of Acetaminophen and Elevated Liver Enzymes

Three Part Question

In [healthy adults], does [recurrent daily intake of 4 grams of acetaminophen] cause [elevated liver enzymes]?

Clinical Scenario

A patient presents to the emergency department with history of recurrent daily 4 grams of acetaminophen use. Blood work shows elevated liver function tests. Can his daily acetaminophen account for this abnormality?

Search Strategy

Medline 1950-04/08 using the OVID interface, Cochrane Library (2008), PubMed clinical queries
[(exp acetaminophen or AND (exp Aspartate Aminotransferases or exp Alanine Transaminase)]. LIMIT to human AND English

Search Outcome

113 papers found of which only 2 papers were relevant


The larger study with a longer treatment duration found significant elevation of ALT. There was also elevation of AST seen but to a lesser degree. Elevation of AST and ALT were not see with a shorter duration of treatment but at higher doses. The duration and long-term implications of these elevations remain unknown. We are not yet at the point of recommending frequent liver monitoring during acetaminophen use, but we should advise patients to take this medication at the lowest effective dose for the shortest time and without exceeding the recommended dose limits. These study results do not pertain to alcoholics, elderly, or those on chronic acetaminophen treatment.

Clinical Bottom Line

Acetaminophen at maximal doses appears to raise liver enzymes. Clinicians prescribing combination formulations should consider use of products with lower (e.g., 325 mg) rather than higher (e.g., 500 mg) doses of acetaminophen.