Intravenous acetaminophen associated with acute liver failure

Area of Science:

• Hepatology
• Pharmacology
• Internal Medicine

Background:

• Acetaminophen (APAP) overdose is a leading cause of acute liver failure (ALF) in many countries.
• Most documented cases involve oral APAP ingestion, with intravenous (IV) APAP-induced ALF being exceptionally rare.

Observation:

• A woman in her mid-60s with a partial colonic obstruction received 13g of IV acetaminophen over 6 days (max 4g/24h).
• She developed encephalopathy and an INR of 6.1, meeting criteria for ALF.
• Other causes of liver failure were excluded.

Findings:

• The patient was treated with IV N-acetylcysteine, leading to resolution of encephalopathy and improved liver chemistries.
• This case represents a rare instance of ALF induced by therapeutic IV acetaminophen administration.

Implications:

• Clinicians should be aware of the potential for IV acetaminophen to cause ALF, even when administered within recommended daily limits.
• Careful patient selection and monitoring are crucial, particularly in patients with risk factors for hepatotoxicity.
• Further research into the specific risks and safe dosing of IV acetaminophen in various clinical settings is warranted.