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Activated Charcoal الفحم النشط

Activated Charcoal الفحم النشط

ACTIVATED CHARCOAL (AC)

1. Introduction

Activated charcoal (AC) is a highly absorbent powder made from superheated, high surface area, porous particles produced by pyrolysis of organic material. Its extensive surface area is covered with a carbon-based network that includes functional groups (e.g., carbonyl, hydroxyl) that adsorb chemicals within minutes of contact, preventing gastrointestinal absorption and subsequent toxicity. Activated charcoal is a supportive measure for reducing absorption of ingested toxins but is not a stand-alone treatment or antidote.

2. Indications

Activated charcoal is indicated within 2 to 4 hours of poison ingestion. It is very useful for anticholinergic drugs, which cause decreased motility and absorption.

3. Substances Adsorbed by Activated Charcoal

ACE inhibitors
Amphetamines
Antidepressants (except lithium)
Aspirin / Salicylates
Barbiturates / Benzodiazepines
Beta / Calcium blockers
Digoxin / Digitalis
Opiates / Paracetamol
Theophylline

* Includes many others: Aconitine, Amatoxin, Chloroquine, Colchicine, Dapsone, Nicotine, etc.

4. Contraindications

  • Nontoxic ingestions
  • Unprotected airway (decreased GCS, uncooperative)
  • Late presentation (> 4 hours)
  • Active vomiting or Bowel obstruction (ileus)
  • Poisons not bound by AC (see table below)

5. Poisons NOT Bound by Activated Charcoal

Category Substances
Heavy MetalsArsenic, Lead, Mercury, Iron, Zinc
Inorganic IonsLithium, Potassium, Sodium, Fluoride
AlcoholsEthanol, Methanol, Isopropanol, Ethylene Glycol
CorrosivesAcids, Alkalis
OthersHydrocarbons, Boric Acid, Essential Oils

6. Dosage & Administration

  • Adults & Adolescents: 25 to 100 g (Usual: 50 g)
  • Children (1–12 yrs): 25 to 50 g or 0.5–1.0 g/kg (Max: 50 g)
  • Infants (< 1 yr): 10 to 25 g or 0.5–1.0 g/kg

Conversion: Teaspoon ≈ 5 g | Tablespoon ≈ 15 g

Mixing Protocol:

  • Adults: 50 g AC + 400 mL water.
  • Children: 1:8 ratio (AC to liquid).
Note: Effectiveness reduces if mixed with milk, syrups, or food.

7. Multiple-Dose Activated Charcoal (MDAC)

Indicated to enhance elimination of specific drugs:

Carbamazepine Dapsone Phenobarbital Theophylline Quinine Aspirin

8. Side Effects

  • Nausea & Vomiting
  • Black stools (Normal finding)
  • Constipation or Diarrhea
  • Aspiration Pneumonitis (Most serious risk)

References:

  • Austin Clinical Toxicology Guideline (v3, 2024).
  • Medical Toxicology Guide, Saudi MOH (2016).
  • DrugBank Online - AC