Activated charcoal is the best proven technique for eliminating most toxic ingestions. Charcoal’s large surface area adsorbs poisons and reduces the amount of free agent available for absorption by means of van der Waals forces and covalent binding. Up to 75% of the toxin may be eliminated when a dose of 1 g of charcoal per kg is given in the first hour of ingestion and repeated every 4 hours as needed. It is especially effective in enhancing the elimination of theophylline, phenobarbital, and carbamazepine, as it can decrease the reabsorption of these drugs as they move through the gut during enterohepatic recirculation, but charcoal is not indicated in all ingestions. It should be used based only on its efficacy for a specific toxin, the toxicity of the ingestion, the elapsed time from ingestion, and individual patient characteristics such as their cooperation, level of consciousness, and presence of vomiting.

There are several significant risks associated with charcoal administration. If it is vomited, which occurs in 15% of treated patients, and then aspirated, it can result in pneumothorax, empyema, pulmonary parenchymal injury, or bronchiolitis obliterans. If charcoal is inadvertently instilled in the lungs through a misplaced orogastric or nasogastric tube, it can result in death.

Importantly, charcoal is ineffective in adsorbing or eliminating alcohols, hydrocarbons, metals, and minerals. Specifically, it should not be used to treat iron, alcohol, lithium, or magnesium ingestions, as the risk far exceeds any benefit. In fact, during the period of 1995 to 1998, more children died from the administration of activated charcoal than the ingestion of alcohol, lithium, or magnesium. Only iron was associated with more deaths.

Although the evidence is limited due to the lack of clinical trials and the limits of case reports and animal and human volunteer models, there are techniques available to reduce the toxicity of iron, alcohol, and lithium overdoses. Treatment may include any combination of supportive care, whole-bowel
irrigation, chelation agents, and hemodialysis. In any ingestion, consult the poison control center for specific recommendations.