A Case of Acute Liver Failure in a Patient on Isoniazid Prophylaxis for Latent Tuberculosis

Isoniazid (INH) is widely used for latent Mycobacterium tuberculosis despite the known risk of liver injury, with severe hepatitis occurring in up to 1% of patients. We report a patient who presented with two weeks of anorexia, nausea, and jaundice following six months of INH monotherapy for latent tuberculosis (TB). After other causes of liver injury were ruled out, she underwent a liver biopsy showing submassive necrosis, hepatocellular dropout, and lobular inflammation with no evidence of fibrosis. She was also found to have acute portal hypertension. She was diagnosed with drug-induced liver injury (DILI) and was treated with n-acetyl cysteine (NAC), ursodiol, and vitamin K. She recovered without the need for a liver transplant. This case supports the need for monitoring of liver tests in high-risk individuals on INH therapy to reduce the risk of hepatotoxicity.