From the Guidelines
Activated charcoal should be administered to patients with known or suspected acetaminophen overdose within 4 hours of presentation, as it may be useful for gastrointestinal decontamination, as recommended by the 2005 AASLD position paper 1. The recommended dose is 1g/kg orally, in a slurry, and it is most effective if given within one hour of ingestion, but may be of benefit as long as 3 to 4 hours after ingestion. Some key points to consider when administering activated charcoal include:
- It works best for medications like acetaminophen, aspirin, tricyclic antidepressants, and many other drugs by binding to toxins in the gastrointestinal tract, preventing their absorption into the bloodstream.
- It is not effective for alcohol, lithium, iron, potassium, or caustic substances.
- Multiple doses may be considered for certain substances like carbamazepine or theophylline that undergo enterohepatic circulation.
- Activated charcoal should not be given to patients with decreased consciousness without airway protection due to aspiration risk, nor to those who have ingested caustic substances.
- Side effects include vomiting, constipation, and black stools. However, more recent guidelines from 2010 and 2015 suggest that activated charcoal should not be administered to a victim who has ingested a poisonous substance unless advised to do so by a poison control center or emergency medical personnel 1. Despite these guidelines, in the context of acetaminophen overdose, the benefits of activated charcoal likely outweigh the risks, and it should be administered as soon as possible after poisoning, ideally within the first hour, as its efficacy decreases significantly with time.
From the Research
Administration of Activated Charcoal in Poisoning
- The American Academy of Clinical Toxicology, European Association of Poisons Centres, and Clinical Toxicologists recommend administration of activated charcoal (AC) within one-hour of an acute toxic ingestion 2.
- A study found that only a small percentage of patients treated for an acute overdose (16%) present within 60 minutes and are given charcoal according to the current guidelines 2.
- Pre-hospital personnel administered AC within 60 minutes to 28% of patients who presented within that time frame 2.
Effectiveness of Activated Charcoal
- Activated charcoal is a safe, effective, inexpensive adjunct in the management of most toxic ingestions 3.
- It has the ability to adsorb a wide variety of drugs and chemicals, including acetaminophen 3.
- A study found that activated charcoal reduces the need for N-acetylcysteine treatment after acetaminophen (paracetamol) overdose 4.
- Activated charcoal appears to reduce the number of patients who achieve toxic acetaminophen concentrations and thus may reduce the need for treatment and hospital stay 4.
Concomitant Use of Activated Charcoal and Other Treatments
- The concomitant use of activated charcoal and N-acetylcysteine is not recommended until further studies are completed 3.
- A study found that activated charcoal did not significantly affect the absorption of N-acetylcysteine 3.
- The use of multiple-dose activated charcoal should be considered only if a patient has ingested a life-threatening amount of certain drugs, such as carbamazepine, dapsone, phenobarbital, quinine, or theophylline 5.
Guidelines for the Use of Activated Charcoal
- The American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists have published position statements and practice guidelines on the use of multi-dose activated charcoal in the treatment of acute poisoning 5.
- These guidelines recommend that multiple-dose activated charcoal should be considered only if a patient has ingested a life-threatening amount of certain drugs 5.
- The administration of multiple-dose activated charcoal is contraindicated unless a patient has an intact or protected airway, and it should not be used in the presence of an intestinal obstruction 5.