Unintentional chronic acetaminophen overuse as an under-recognised cause of liver injury

Acetaminophen (APAP) toxicity is the most common cause of acute liver failure, with the majority of cases resulting from acute overdose. However, chronic toxicity is much less frequently reported and more difficult to detect. This case presents a patient found to be taking supratherapeutic doses of APAP for 4 weeks, leading to acute liver injury. Despite undetectable serum APAP levels and absence of acute liver failure (ALF) signs, he was treated with N-acetylcysteine, which significantly improved his marked transaminitis. This case highlights the importance of vigilance and history taking for early identification and prevention of ALF in chronic APAP toxicity.