Oxaprozin-induced symptomatic hepatotoxicity

To describe a case of symptomatic hepatotoxicity attributed to oxaprozin use.

A 41-year-old white woman was admitted to the hospital with malaise, anorexia, and right upper quadrant pain. The patient was found to have severe jaundice with liver enzyme elevation. Laboratory test results for potential etiologies were negative, except for the use of oxaprozin for the preceding six weeks. Diagnosis of drug-induced hepatotoxicity was made by liver biopsy. The patient's symptoms resolved and liver enzymes normalized after oxaprozin was discontinued.

Symptomatic hepatic effects attributable to most nonsteroidal antiinflammatory drugs (NSAIDs) are rare and usually mild. Oxaprozin has been shown to cause mild elevation of liver enzymes in clinical studies. This is the second reported case of presumed oxaprozin-induced icteric hepatitis. The mechanism of oxaprozin-induced hepatotoxicity is unclear, but is thought to be due to metabolic idiosyncrasy. Most NSAID reactions are hepatocellular and occur because of individual susceptibility (idiosyncrasy). In general, people aged >40 years and women are more predisposed to NSAID-induced liver injury.

Although this toxicity is rare, clinicians should be aware of the potential for oxaprozin to cause hepatotoxicity and use caution when prescribing this medication. This case also stresses the importance of careful inquiry regarding drug or toxin exposure in cases of unexplained hepatitis.