A 22-year-old woman is brought to the emergency department 8 hours after intentionally ingesting a large quantity of acetaminophen tablets. She reports nausea and vomiting but is otherwise asymptomatic. Temperature is 36.8°C (98.2°F), blood pressure is 118/70 mm Hg, pulse is 88/min, and respiratory rate is 14/min. Physical examination is unremarkable. Initial laboratory studies reveal normal liver enzyme levels. Serum acetaminophen concentration is plotted on the Rumack-Matthew nomogram and falls within the treatment range.
Which of the following is the most appropriate next step in management?
The correct answer is:
C: N-acetylcysteine therapy.
This patient has potentially toxic acetaminophen ingestion with a serum concentration above the treatment threshold. N-acetylcysteine replenishes hepatic glutathione stores and prevents formation of toxic metabolites that cause liver injury. Treatment is most effective when initiated early and should not be delayed while awaiting liver enzyme elevation.
Answer choice A: Activated charcoal only, is incorrect.
Activated charcoal may be useful shortly after ingestion but is insufficient as sole therapy when antidotal treatment is indicated.
Answer choice B: Emergent liver transplantation, is incorrect.
Liver transplantation may be required in patients with fulminant hepatic failure but is not indicated in this early presentation.
Answer choice D: Observation and discharge, is incorrect.
Patients whose acetaminophen level falls within the treatment range require antidotal therapy because clinically significant liver injury may develop later.
Answer choice E: Prednisone therapy, is incorrect.
Corticosteroids have no established role in the treatment of acetaminophen toxicity.
Key Learning Point
N-acetylcysteine should be administered promptly after significant acetaminophen ingestion when acetaminophen levels meet treatment criteria, even before liver injury becomes apparent.
