Acetaminophen toxicity is one of the major causes of acute liver failure worldwide. Due to wide availability and perception regarding safety, it also remains the commonest drug used in cancer pain settings. Incidental detection of acute liver failure during the hospital course may be observed in cachexia cancer patients. N-acetyl cysteine (NAC) can be used as a rescue drug in case of liver injury as manifested clinically or from altered lab values. There are only a few cases reported of acetaminophen toxicity in malnourished subjects. This case report can provide insight into the importance of reduction of dosage of acetaminophen in cachectic patients.

A 47-year-old female patient with no known comorbidities was diagnosed with locally advanced squamous cell carcinoma mid-oesophagus. She was advised best supportive care and was referred to the palliative medicine department where she presented with complaints of central chest pain and absolute dysphagia. General examination revealed a body weight of around 30 kg, Body Mass Index (BMI) of 14.5, and performance status of 4. Her analgesics included an injection of tramadol 50 mg twice daily and an injection of paracetamol 1 g thrice daily. During the course of her stay in the hospital routine examinations revealed an acute rise in the liver enzymes, aspartate transaminase (AST) was 1526 U/L, and alanine transaminase (ALT) was 1880 U/L, compared to the previous day values (on admission to the department the AST and ALT values were 38 and 40 U/L, respectively). Acute liver injury due to paracetamol overdose was suspected. N-acetyl cysteine was initiated according to the 21-hour protocol. Later liver enzymes declined and the patient improved clinically and was discharged home in a stable condition.

This case report underlines the importance of cautious dose reduction of acetaminophen in chronic pain patients with less than 50 kg to not more than 2 g per day for the prevention of acute liver failure.