What is the treatment for a paracetamol (Acetaminophen) overdose?

From the Guidelines

The patient should be immediately taken to the emergency department for treatment with N-acetylcysteine (NAC) as soon as possible, as it is the most effective treatment for paracetamol overdose, especially when started within 8 hours of ingestion 1. The amount ingested, time since ingestion, and blood paracetamol levels will be assessed by healthcare providers to determine the best course of action.

• NAC works by replenishing glutathione stores in the liver, which helps detoxify the harmful metabolite of paracetamol called NAPQI that causes liver damage.
• The standard NAC protocol involves an initial loading dose of 150 mg/kg over 60 minutes, followed by 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours.
• Activated charcoal may be administered if the patient presents within 1-2 hours of ingestion to reduce drug absorption.
• During treatment, liver function tests and paracetamol levels will be monitored regularly.
• The effectiveness of NAC in preventing liver damage decreases significantly with delayed treatment, which is why seeking immediate medical attention is crucial for anyone suspected of paracetamol overdose 1. Given the patient's age and the amount of paracetamol ingested, it is essential to prioritize immediate medical attention to minimize the risk of liver damage and other complications 1. In cases of paracetamol overdose, prompt treatment with NAC can significantly improve outcomes, and it is crucial to seek medical help as soon as possible to maximize the effectiveness of treatment 1.

From the FDA Drug Label

14 CLINICAL STUDIES

A subgroup of 58 subjects (33 in the 15-minute infusion group; 25 in the 60-minute infusion group) was treated within 8 hours of acetaminophen ingestion. A post-hoc analysis identified 56 patients who (1) were at high or probable risk for hepatotoxicity (APAP greater than 150 mg/L at the four hours line according to the Australian nomogram) and (2) had a liver function test Of the 53 patients who were treated with intravenous acetylcysteine (300 mg/kg intravenous acetylcysteine administered over 20 to 21 hours) within 8 hours, two (4%) developed hepatotoxicity (AST or ALT greater than 1000 U/L).

For a 77-year-old patient who has taken 10 tablets of paracetamol in a day by accident, the treatment for a paracetamol (Acetaminophen) overdose is intravenous acetylcysteine.

• The patient should be treated with intravenous acetylcysteine (300 mg/kg) administered over 20 to 21 hours as soon as possible, preferably within 8 hours of acetaminophen ingestion.
• It is essential to monitor liver function tests and AST or ALT levels to assess the risk of hepatotoxicity.
• The patient's age and condition should be taken into consideration when administering the treatment, and close monitoring is necessary to prevent any potential adverse reactions 2.

From the Research

Treatment for Paracetamol Overdose

The treatment for paracetamol (acetaminophen) overdose involves several interventions, including:

• Inhibition of absorption, such as activated charcoal, gastric lavage, or ipecacuanha
• Removal of paracetamol from the vascular system
• Antidotes, such as N-acetylcysteine, to prevent the formation of or to detoxify metabolites
• Liver transplantation in severe cases

Interventions to Reduce Absorption

Studies have shown that:

• Activated charcoal seems to have the best risk-benefit ratio among interventions to reduce absorption 3, 4, 5
• Gastric lavage and ipecacuanha may also reduce absorption, but their clinical benefits are unclear 3, 4, 5
• Activated charcoal is most effective when given within 4 hours of ingestion 4, 6

Antidotes

• N-acetylcysteine is the preferred antidote for paracetamol overdose, as it seems to reduce mortality in patients with fulminant hepatic failure 3, 4, 5
• The optimal N-acetylcysteine treatment protocol is unclear, but it should be given to patients at risk of toxicity, including those presenting with liver failure 3, 4, 5
• Increased doses of acetylcysteine may be beneficial in patients with high paracetamol concentrations 6

Clinical Outcomes

• Studies have shown that patients who receive both activated charcoal and N-acetylcysteine after acute acetaminophen overdoses may have improved outcomes, including reduced rates of hepatotoxicity and death 7
• Massive paracetamol overdose can result in hepatotoxicity despite early treatment, but treatment with increased acetylcysteine dose within 21 hours may reduce the risk of hepatotoxicity 6