From the Guidelines
The treatment for Tylenol (acetaminophen) poisoning primarily involves administering N-acetylcysteine (NAC), which should be started as soon as possible after ingestion, ideally within 8 hours, as recommended by the most recent and highest quality study 1. The standard regimen for NAC administration can be either oral or intravenous. For oral administration, a loading dose of 140 mg/kg is given, followed by 70 mg/kg every 4 hours for 17 additional doses. Alternatively, intravenous NAC can be administered as a 150 mg/kg loading dose over 60 minutes, then 50 mg/kg over 4 hours, followed by 100 mg/kg over 16 hours. Some key points to consider in the management of acetaminophen overdose include:
- Activated charcoal can be administered if the patient presents within 1-2 hours of ingestion to reduce absorption, as noted in 1.
- Medical evaluation includes measuring acetaminophen blood levels (typically 4 hours post-ingestion) and liver function tests.
- NAC works by replenishing glutathione stores in the liver, which are depleted during acetaminophen metabolism, thereby preventing the toxic metabolite NAPQI from causing liver damage, as explained in 1.
- The Rumack-Matthew nomogram can be used to determine the risk of hepatotoxicity based on the serum acetaminophen concentration and the time of ingestion, as discussed in 1.
- Prompt treatment is essential as acetaminophen poisoning can cause irreversible liver damage if left untreated, highlighting the importance of early intervention, as emphasized in 1 and 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION General Regardless of the quantity of acetaminophen reported to have been ingested, administer acetylcysteine solution immediately if 24 hours or less have elapsed from the reported time of ingestion of an overdose of acetaminophen. The following procedures are recommended:
- The stomach should be emptied promptly by lavage or by inducing emesis with syrup of ipecac.
- Administer the loading dose of acetylcysteine, 140 mg per kg of body weight.
The treatment for Tylenol poisoning is immediate administration of acetylcysteine. The stomach should be emptied promptly, and a loading dose of 140 mg/kg of acetylcysteine should be administered. Subsequent doses and treatment should be determined based on the predetoxification plasma acetaminophen level and other clinical factors 2.
- Key steps in treatment include:
- Emptying the stomach
- Administering acetylcysteine
- Monitoring liver function and other clinical parameters
- Important considerations:
- Treatment should be started immediately if the overdose occurred within 24 hours
- The patient's ability to retain the orally administered acetylcysteine should be monitored, and alternative administration methods may be necessary if the patient is unable to retain the dose 2.
From the Research
Treatment for Tylenol Poisoning
- The treatment for Tylenol poisoning involves several steps, including initial history, referral to an emergency department, and administration of activated charcoal and N-acetylcysteine 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 (Grade A) 3.
- N-acetylcysteine seems preferable to placebo/supportive treatment, dimercaprol, and cysteamine, but its superiority to methionine is unproven 4.
- Administration of activated charcoal in addition to standard N-acetylcysteine therapy after acetaminophen overdose may provide additional patient benefit over NAC therapy alone 5, 6.
- Oral methionine is as effective as acetylcysteine in preventing severe liver damage and death after acetaminophen overdose, but it must be given within ten hours of ingestion to be effective 7.
Referral to Emergency Department
- 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 (Grade D) 3.
- Patients less than 6 years of age should be referred to an emergency department if the estimated acute ingestion amount is unknown or is 200 mg/kg or more 3.
- Patients 6 years of age or older should be referred to an emergency department if they have ingested at least 10 g or 200 mg/kg (whichever is lower) or when the amount ingested is unknown (Grade D) 3.