Late-Onset Acute Liver Injury From Azathioprine

Azathioprine is a widely prescribed immunosuppressant. Although hepatotoxicity is rare, it commonly presents as mild asymptomatic liver enzyme elevation or acute cholestatic liver injury. We report a case of a 46-year-old woman who presented with jaundice, abdominal pain, fatigue, and elevated aminotransferases in a cholestatic pattern. Endoscopic retrograde cholangiopancreatogram demonstrated no abnormalities, and recently started medications were discontinued without improvement. Liver biopsy was performed, which was consistent with drug-induced liver injury. Despite multiple years of treatment without issue, after azathioprine was discontinued, symptoms and laboratory abnormalities resolved. This case highlights azathioprine's potential for hepatotoxicity even multiple years after initiation.