What is the management of acetaminophen (Tylenol) overdose?

From the Guidelines

Tylenol (acetaminophen) overdose management should prioritize immediate administration of N-acetylcysteine (NAC) to patients with possible or probable risk for hepatotoxicity as determined by the Rumack-Matthew nomogram, ideally within 8 to 10 hours postingestion, as recommended by the Annals of Emergency Medicine 1.

Key Considerations

• The Rumack-Matthew nomogram is used to determine the risk of hepatotoxicity in patients with acetaminophen overdose, and NAC treatment should be initiated based on this assessment 1.
• NAC is most effective when started within 8 hours of ingestion, but may still be beneficial up to 24 hours post-ingestion 1.
• Activated charcoal may be administered if the patient presents within 1-2 hours of ingestion to reduce absorption, but it should not delay the administration of NAC 1.

Treatment Protocol

• NAC is typically given as an IV loading dose of 150 mg/kg over 60 minutes, followed by 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours 1.
• Oral NAC can be used in some cases at 140 mg/kg initially, followed by 70 mg/kg every 4 hours for 17 doses 1.

Monitoring and Supportive Care

• Doctors will measure acetaminophen blood levels and liver function tests to guide treatment decisions 1.
• Supportive care including IV fluids and anti-nausea medication may also be provided to manage symptoms and prevent complications 1.
• Severe cases may require liver transplantation if liver failure develops, and early contact with a transplant center is recommended 1.

From the FDA Drug Label

In the case of a mixed drug overdose, activated charcoal may be indicated. However, if activated charcoal has been administered, lavage before administering acetylcysteine solution treatment. 3 Draw blood for predetoxification acetaminophen plasma assay and baseline SGOT, SGPT, bilirubin, prothrombin time, creatinine, BUN, blood sugar and electrolytes. 4. Administer the loading dose of acetylcysteine, 140 mg per kg of body weight. 5. Determine subsequent action based on predetoxification plasma acetaminophen information.

The management of Tylenol overdose involves:

• Stomach emptying by lavage or inducing emesis with syrup of ipecac
• Administration of activated charcoal if indicated, followed by lavage before acetylcysteine treatment
• Drawing blood for predetoxification acetaminophen plasma assay and baseline laboratory tests
• Administering a loading dose of acetylcysteine (140 mg/kg) and subsequent maintenance doses based on plasma acetaminophen levels 2
• Monitoring hepatic and renal function and electrolytes throughout the treatment process
• Considering the time of ingestion and plasma acetaminophen levels to determine the need for continued treatment 2

From the Research

Tylenol Overdose Management

• The management of Tylenol (acetaminophen) overdose involves several steps, including initial history, referral to an emergency department, and administration of activated charcoal and N-acetylcysteine 3.
• The initial history should include the patient's age, intent, specific formulation and dose of acetaminophen, ingestion pattern, duration of ingestion, and concomitant medications 3.
• Any patient with stated or suspected self-harm or who is the recipient of a potentially malicious administration of acetaminophen should be referred to an emergency department immediately, regardless of the amount ingested 3.
• Activated charcoal can be considered if local poison center policies support its prehospital use, a toxic dose of acetaminophen has been taken, and fewer than 2 hours have elapsed since the ingestion 3.

Administration of Activated Charcoal

• Administration of activated charcoal in addition to standard N-acetylcysteine (NAC) therapy after acetaminophen overdose may provide additional patient benefit over NAC therapy alone 4.
• Activated charcoal seemed to reduce the absorption of paracetamol, but the clinical benefits were unclear 5.
• Activated charcoal seemed to have the best risk:benefit ratio among gastric lavage, ipecacuanha, or supportive treatment if given within four hours of ingestion 5.

Use of N-Acetylcysteine

• N-acetylcysteine (NAC) is the specific antidote available for serious overdoses of acetaminophen 6.
• Acetylcysteine appeared superior to placebo and had fewer adverse effects when compared with dimercaprol or cysteamine 5.
• Acetylcysteine should be given to people at risk of toxicity, including people presenting with liver failure 5.

Combination Therapy

• The combination of N-acetylcysteine and activated charcoal may be more effective than N-acetylcysteine alone in enhancing acetaminophen elimination in overdosed patients 7.
• The combination therapy may provide additional hepatoprotective benefit 7.