People vs. animals
Based on the results of these studies, the administration of activated charcoal to people beyond an hour of exposure is generally
not recommended; however, the potential benefit when given beyond an hour cannot be excluded.1,2
While immediate administration of activated charcoal is ideal, that is difficult to achieve in veterinary medicine. Because
of the amount of time it takes to drive to the clinic, to triage, and to physically deliver activated charcoal (e.g. syringe feeding, orogastric tube), administration is generally delayed at least 30 minutes and often up to an hour or more.2 And as the time since ingestion is frequently unknown (e.g. pet owners coming home from work to find their pets poisoned), decontamination is often a relatively benign course of action,
provided the patient is not already exhibiting clinical signs. As always, when administering any drug, it is important that
the benefits outweigh the risks and that complications be prevented whenever possible.
In veterinary medicine, administration of activated charcoal with a cathartic as long as six hours out may still be beneficial
with certain toxicoses, particularly if the toxicant has delayed release (e.g. extended or sustained release) or undergoes enterohepatic recirculation.5 More important, the limited availability of specialized modalities of therapy (e.g. antidotes [digoxin-specific antibody fragments, 2-PAM], plasmaparesis, hemodialysis, mechanical ventilation) along with the
financial limitations of pet owners warrant the aggressive use of activated charcoal in veterinary medicine, when appropriate,
since it is often the last line of defense in decontamination of a patient.2
Activated charcoal should only be administered to asymptomatic patients to prevent secondary complications from its administration.
If the patient is symptomatic, care should be taken to protect the airway with an inflated endotracheal tube to prevent aspiration
of vomitus or activated charcoal.
Before activated charcoal is administered, the patient's hydration status should be assessed to determine if fluid therapy
is warranted. There have been published human case reports6,7 and anecdotal clinical reports in veterinary medicine of severe hypernatremia occurring secondary to administration of activated
charcoal with a cathartic (e.g. sorbitol); thus, patients should be adequately hydrated when given activated charcoal.