From the Guidelines
Administering activated charcoal at a dose of 1 gram per kilogram is recommended for patients with known or suspected acetaminophen overdose within a few hours of presentation, as it may be useful for gastrointestinal decontamination. This dosage is based on the standard dose mentioned in the study published in Hepatology 1. For an average adult, this typically translates to about 50-100 grams as a single dose. Activated charcoal is primarily used for acute poisoning or drug overdose situations, as it works by binding to toxins in the gastrointestinal tract, preventing their absorption into the bloodstream.
The medication should be administered as soon as possible after ingestion of the toxin, ideally within one hour, as its effectiveness decreases significantly after this time 1. It comes as a powder that is mixed with water to form a slurry or as a premixed liquid suspension. When administering, ensure the patient is alert enough to swallow safely to prevent aspiration. Activated charcoal is not effective for all types of poisonings, particularly with alcohols, strong acids/alkalis, lithium, iron, or petroleum products.
Some key points to consider when administering activated charcoal include:
- 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 1.
- Administration of activated charcoal just prior to administration of N-acetylcysteine does not reduce the effect of N-acetylcysteine 1.
- Side effects may include black stools, vomiting, and constipation.
- Multiple doses may be required for certain toxins that undergo enterohepatic circulation. The charcoal works through adsorption, where toxins bind to its large surface area, allowing them to be eliminated through the digestive tract rather than absorbed into the body. According to the recommendations outlined in the study published in Hepatology 1, for patients with known or suspected acetaminophen overdose within 4 hours of presentation, giving activated charcoal just prior to starting NAC is recommended.
From the Research
Effect of Administering Activated Charcoal
- The effect of administering activated charcoal at a dose of 1 gram per kilogram is to reduce the gastrointestinal (GI) absorption of many drugs and enhance drug elimination 2.
- Activated charcoal is most effective when administered within 1 hour of ingestion, with its effectiveness decreasing over time 3, 4.
- A dose of 0.5-1 g/kg body weight is recommended for children, while 50 g is recommended for adults 5.
- In some cases, repeated application of activated charcoal may be indicated, such as for intoxications with agents that persist for a longer time in the stomach or for intoxications with timed-release drugs 5.
- A specific protocol for the use of activated charcoal-sorbitol mixture has been devised, with a recommended dose of 1 g/kg of activated charcoal in 4.3 ml/kg body weight of 70% sorbitol every 4 hours until the first stool containing charcoal appears 6.
Key Considerations
- The administration of activated charcoal should be carried out as soon as possible, within the first hour of the ingestion 5.
- Activated charcoal is ineffective or inadequately effective in cases of poisoning with acids or bases, alcohols, organic solvents, inorganic salts, or metals 5.
- The routine combination of activated charcoal with a laxative is not recommended 5.
- Patients requiring multiple doses should be closely monitored for any fluid or electrolyte imbalance or depletion of essential vitamins 6.