coal activated carbon pellets absorbs a wide variety of drugs and chemicals. Adsorption is a process in which atoms and molecules move from a bulk phase (such as a solid, liquid, or gas) onto a solid or liquid surface. In other words, the toxic substance attaches to the surface of the charcoal. Because charcoal is not "digested," it stays inside the GI tract and eliminates the toxin when the person has a bowel movement.
This mechanism of action should not be confused with absorption. Absorption occurs when a substance passes into or through a tissue, like water passing into a sponge. Once the chemical or drug has been absorbed by the GI tract, activated charcoal can no longer retrieve the toxic ingestion. It will only attach to substances that are still inside the stomach or intestines.
The charcoal is "activated" because it is produced to have a very fine particle size. This increases the overall surface area and adsorptive capacity of the charcoal. It is produced by adding acid and steam to carbonaceous materials such as wood, coal, rye starch, or coconut shells. To put this in perspective, one standard 50-gram dose of activated charcoal has the surface area of 10 football fields.
Activated charcoal does not irritate the mucous membranes of the GI system. In addition to adsorption of toxins, activated charcoal also adsorbs food nutrients, vitamins, and minerals. However, this short-term effect is not a concern when activated charcoal is used to treat poisoning.
A few poison centers recommend the use of activated charcoal in specific circumstances. Call your local poison control center for guidance before giving it to someone. In areas in which the poison center recommends carbon pellets, pharmacies will stock the product, and it can be purchased over-the-counter. In general, if the local poison center does not recommend its use at home, pharmacies will not stock it.