Activated Charcoal
CLASS
- decontamination agent
MECHANISM OF ACTION
- adsorbs molecules of drug on its surface, which inhibits their absorption by as much as 50% and leads to their excretion in faeces
- absorptive area = 3,000 m2/g
PHARMACEUTICS
- odourless, tasteless, fine black powder
- chemically inert form of carbon prepared by pyrolysis of carbonaceous matter (coconut, pulverised peat or sawdust) at 600-900 C in a kiln without air.
- then concentrated with zinc chloride solution, washed off with dilute acid & water, and exposed to steam or CO2 at 600-700 C that forms an internal maze of pores.
DOSE
- 1g/kg
- 50g in 100mL
- should be given within 1 h
- can be given later dependent on characteristics of the ingested agent, for instance may be appropriate if the drug:
- is not lipid soluble
- has slow passage to intestine
- is a sustained release preparation, and/or
- ingested with other agents that slow gastrointestinal absorption of durgs (e.g. anticholinergics)
INDICATIONS
- Used for decontamination of the gastrointestinal tract following ingestion of a potentially toxic agent
- give if toxic agent is still within the gastrointestinal tract (e.g. within 1 hour) and potential benefits out weigh risks.
- Useful in overdose from:
- aspirin
- paracetamol
- barbiturates
- TCA’s
- digoxin
- amphetamines
- morphine
- cocaine
- phenothiazines
Multi-dose activated charcoal can be used in selected cases for decontamination (e.g. where absorption is greatly delayed) or enhanced elimination (e.g. where there ther is entero-hepatic circulation) (see enhanced elimination)
ADVERSE EVENTS
- vomiting
- pulmonary aspiration
- direct administration to lung via N/G tube -> potentially fatal
- impaired absorption of oral medications/antidotes
- corneal abrasions
- constipation/bowel obstruction
PHARMACOKINETICS
- Absorption
- Distribution
- Metabolism
- Elimination
EVIDENCE
- single dose activated charcoal is generally the preferred method of decontamination but does not improve outcome when applied to unselected patients
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
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Hi Chris,
I am pretty confident that Charcoal’s mechanism of action is by adsorption of Solids, Liquids & gases on its surface, and does not have any absorbing properties, and is very good due to its large surface area. Thats one of the reasons one of its use in daily life is as a good deodoriser for a refrigerator, and be reused by washing it again.