- decontamination agent
MECHANISM OF ACTION
- absorbing molecules of drug on its surface -> inhibiting their absorption by as much as 50% -> excretion in faeces
- absorptive area = 3,000m2/g
- odourless, tasteless
- fine black powder
- chemically inert form of carbon
- prepared by pyrolysis of carbonaceous matter (coconut, pulverised peat or sawdust) @ 600-900 C in a kiln without air.
- then concentrated with zinc chloride solution -> washed off with dilute acid & water -> exposed to steam or CO2 at 600-700 C -> forms an internal maze of pores.
- 50g in 100mL
- should be given within 1 hr
- can be given later OD drug not lipid soluble, slow passage to intestine, sustained release preparation or ingested with anti-cholinertics
- give if toxic agent is still within the GI tract (within 1 hour) and potential benefits out weigh risks.
- useful in overdose from:
- pulmonary aspiration
- direct administration to lung via N/G tube -> potentially fatal
- impaired absorption of oral medications/antidotes
- corneal abrasions
- constipation/bowel obstruction
- single dose activated charcoal is generally the preferred method of decontamination but does not improve outcome when applied to unselected patients