Acute liver injury associated with nonsteroidal anti-inflammatory drugs and the role of risk factors.

BACKGROUND: Hospitalizations for acute liver injury in the absence of a viral infection or any other well-defined pathologic finding that could have caused it is rare. In this study, we included both outpatients and hospitalized patients with acute liver injury to estimate the risk of clinically important acute liver injury associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and to study the role of certain risk factors.

METHODS: This was a retrospective cohort study with secondary case-control analysis. The study included 536 general practitioners' practices in England and Wales for the period October 1987 through August 1991. A total of 625,307 persons who received more than 2 million prescriptions for one of 12 NSAIDs were followed up to estimate the risk of newly diagnosed acute liver injury.

RESULTS: There were 23 cases of acute liver injury. The incidence of acute liver injury was 3.7 per 100,000 NSAID users or 1.1 per 100,000 NSAID prescriptions. None of the cases had a fatal outcome. Sulindac was the only NSAID with a substantially greater risk than that for the overall NSAID group. Users of NSAIDs who had rheumatoid arthritis had a 10-fold increased risk of acute liver injury compared with NSAID-treated patients with osteoarthritis. Concomitant exposure to other hepatotoxic medications also increased the risk. Transient minor increases in liver test values were not a useful predictor of diagnosed NSAID-associated acute liver injury.

CONCLUSIONS: Although NSAIDs have been found to be associated with acute liver injury in a small number of persons, the risk is sufficiently small as to be of minimal concern for most NSAIDs.