Severe Acetaminophen Toxicity From the Use of Oxycodone-Acetaminophen With Normal Liver Function Tests and a Completely Asymptomatic Course of Hospitalization

Acetaminophen (N-acetyl-p-aminophenol, APAP), after being metabolized to toxic N-acetyl-p-benzoquinone imine, can cause irreversible hepatic necrosis. The mainstay of treatment includes N-acetylcysteine and fomepizole or liver transplant in patients who further deteriorate. Currently, many overdoses unintentionally occur in the setting of ingesting combined products that contain APAP. We report a rare case of a 60-year-old woman who presented with altered mental status and APAP toxicity in the setting of oxycodone-APAP overdose. She had a toxic serum APAP level on arrival. During hospitalization, her APAP level remained at the toxic level on the Rumack-Matthew nomogram. However, her liver function tests remained within normal limits, and she remained completely asymptomatic. To our best knowledge, this is the second case report with asymptomatic APAP toxicity and normal liver function tests. We will explore the effect of concomitant oxycodone ingestion on possibly delaying APAP absorption and thus resulting in a more favorable prognosis without hepatotoxicity.