There is actually very little data that actually supports the administration of activated charcoal (AC) to the poisoned patient. AC works by binding the toxin and preventing its absorption from the GI tract. Here are some of the practical points:
Most effective if given within one hour of the overdose
Do not give if patient is sedated, going to be sedated or has a chance for seizure
Always assess risk of aspiration versus possibly binding drug by asking the following:
Is this drug dangerous enough that I have to try to prevent its absorption?
Can this drug cause sedation, seizures or impair protective airway reflexes?
Do I lack an antidote or alternative treatment?
Once you have assessed your risk:benefit ratio, then administer AC. Of note, it definitely works in the right situation as noted in a landmark article that showed a decrease in mortality following poisoning by oleander - a plant that contains a digoxin like substance.(1)
1 - de Silva HA, et al. Multiple-dose activated charcoal for treatment of yellow oleander poisoning: a single-blind, randomised, placebo-controlled trial. Lancet 2003: 361(9373):1935-8.
