activated charcoal {with sorbitol} (Insta-Char, Actidose)

Introduction

Produced by heating wood pulp to 900 degrees C, washing, then activating with steam of strong acid.

Absorbs a wide variety of toxins ranging in size from 100-1000 g/mol preventing their absorption from the GI tract.

Indications

• general purpose antidote for oral poisonings
• when using in combination with ipecac, induction of vomiting must be complete prior to use of activated charcoal
• uremia: absorbs creatinine, uric acid, urea & organic acids from GI tract
• most effective within 30 minutes of poison ingestion
• generally given with a cathartic
  • either sorbitol or magnesium citrate

Contraindications

• activated charcoal does not absorb:
  • heavy metals - iron
  • lithium
  • alcohols
  • high ionized compounds
  • caustic agents
  • cyanide
• factors which render activated charcoal less useful
  • non-toxic ingestions
  • very small ingestions
  • maximum toxic effect reached or passed
  • suspension or liquid (except paraquat/diquat)
  • risk of aspiration > benefit of charcoal

pregnancy-category +

safety in lactation +

Dosage

• 50 g alone plus 50 g with 50 g of sorbitol (adults)
• 1-2 gm/kg (children)
• 50 g every 4 hours for adults with 50 g of sorbitol no more than every 3rd dose of charcoal
• 10 times the estimated amount of drug
• administered as a well-mixed slurry
• cathartics with 1st dose only
• multiple doses of charcoal necessary
  • phenobarbital, carbamazepine, quinine, dapsone, theophylline
  • possibly: salicylates, digitoxin, phenytoin

Monitor

bowel sound to avoid impactation in the event of ileus

Drug interactions

• multiple dose activated charcoal may enhance excretion of theophylline, phenobarbital, phenytoin, carbamazepine.

Mechanism of action

• small pores capable of adsorbing molecules 100-1000 g/mol
• a gram of activated charcoal has approximately 1000 square meters of surface area
• reversible adsorption of toxins
  • preventing absorption from the GI tract
  • interrupts enterohepatic recirculation of some drugs & toxins
  • diffusable drugs may cross into the gut from the bloodstream (gut dialysis)

More general terms

• antidote

Additional terms

• toxicity; poisoning; overdose

Component of

• activated charcoal/sorbitol