Activated Charcoal: A Quick Summary of a Summary inspired by Dr. Ahra Cho
With all the Tox VMRs going on, we often turn to activated charcoal as a method of decontamination, but we don’t often talk about how exactly activated charcoal works and why sometimes it doesn’t work. The following is adapted from StatPearls.
- Toxic ingestions that occur within 1 hour of treatment
- Can widen the window up to 4 hours if it is a large ingestion, delayed/extended release ingestion, or the ingestant decreases GI motility
- Pt needs to be able to protect their airway (gag reflex in place, alert/oriented)
- Ingestant should be absorbed by charcoal
Mechanism of action
- Lines the GI mucosa and binds toxins preventing initial absorption or reabsorption via enteroheaptic or entero enteric recirculation.
- Basically works via equilibrium of unbound charcoal complex to charcoal-toxin complex with greatest efficiency when this ratio is around 10:1.
- Best absorbs: Non polar, poorly water soluble organic toxins
- Works well for: acetaminophen, aspirin, barbiturates, tricyclic antidepressants, theophylline, phenytoin, and a majority of inorganic and organic materials
- Does not work well for: alcohols, metals such as iron and lithium, electrolytes such as magnesium, potassium, or sodium, and acids or alkalis
- Oral, OG or NG depending on what is tolerated
- If known ingestion amount, attempt 10:1 weight based (may be difficult in large ingestion)
- If unknown, single dose: 50g-100g
- If unknown, multi dose (for medications that recirculate):
- Loading dose of 25g-100g
- Repeat 10g-25g q2-4hours
- Primarily aspiration/emesis
- High perforation risk
Now you know.