Management of Acetaminophen Overdose in Patients with Dengue

Introduction to NAC Therapy

The American College of Medical Toxicology recommends administering NAC to all patients with hepatotoxicity and suspected acetaminophen overdose, including repeated supratherapeutic ingestions 1
The standard 21-hour IV protocol consists of: 150 mg/kg loading dose over 15 minutes, then 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours, as recommended by the Hepatology society 2, 3, 4

A dose of 5g acetaminophen is below the typical threshold for acute liver failure, which usually requires ingestions exceeding 10g/day, though severe injury can rarely occur with doses as low as 3-4g/day, according to the Hepatology society 2, 3
Current ALT of 88 IU/L is far below the high-risk threshold—very high aminotransferases exceeding 3,500 IU/L are highly correlated with acetaminophen poisoning and impending liver failure, as stated by the Praxis Medical Insights society 1, 2
Repeat AST/ALT/PT-INR every 12-24 hours for the first 72 hours to detect evolving hepatotoxicity, as recommended by the Praxis Medical Insights society 1

Hepatic encephalopathy (altered mental status, confusion, asterixis) is a red flag for fulminant liver failure, according to the Hepatology and Anaesthesia societies 2, 5
Coagulopathy (PT/INR >1.5, spontaneous bleeding) is a red flag for fulminant liver failure, as stated by the Hepatology and Anaesthesia societies 2, 5
Severe transaminitis (AST/ALT >1000-3500 IU/L) is a red flag for fulminant liver failure, according to the Hepatology society and Praxis Medical Insights society 1, 2
Contact transplant center immediately if any signs of acute liver failure develop, as recommended by the Hepatology society 2, 3

NAC reduces mortality from 80% to 52% in fulminant hepatic failure, according to the Praxis Medical Insights society 1
Do not stop NAC prematurely based on "low" acetaminophen levels—low or absent levels do not rule out toxicity if ingestion was remote or occurred over several days, as stated by the Hepatology society and Praxis Medical Insights society 1, 2
Do not rely solely on the Rumack-Matthew nomogram in this case—it does not apply to repeated supratherapeutic ingestions over 24 hours, according to the Praxis Medical Insights society 1
Do not delay NAC continuation decisions—efficacy is time-dependent, with severe hepatotoxicity developing in only 2.9% when NAC starts within 8 hours versus 26.4% when started 10-24 hours post-ingestion, as recommended by the Praxis Medical Insights society 1