>18 hours post-ingestion).
- AIRWAY MANAGEMENT (MDX): Perform aggressive airway protection in patients with signs of encephalopathy or CNS depression if concomitant drugs like opioids are ingested.
- ANTIDOTE: NAC (MDX): Acetylcysteine should be administered to any patient at risk for hepatic injury (either serum acetaminophen concentration above the possible toxicity line on the Rumack-Matthew Nomogram, or history of ingesting more than 200 mg/kg or 10 g [whichever is less] and serum concentration not available or time of ingestion not known), and to patients who have hepatic injury and a history of acetaminophen overdose. Both therapeutic serum concentrations of N-acetylcysteine and high concentrations of acetaminophen can elevate the INR. These elevations are usually mild (INR should not be greater than 1.5), occur between 4 and 20 hours post ingestion, and resolve as treatment is continued (UTD). If a patient vomits within 60 minutes of an oral dose of N-acetylcysteine, the dose should be repeated. Persistent vomiting in spite of antiemetic therapy is an indication to administer N-acetylcysteine intravenously