Activated Carbon

Activated carbon, also called activated charcoal or activated coal, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.[1] 
The word activated in the name is sometimes replaced with active. Due to its high degree of microporosity, just 1 gram of activated carbon has a surface area in excess of 500 m2 (about one tenth the size of an American football field), as determined typically by nitrogen gas adsorption. Sufficient activation for useful applications may come solely from the high surface area, though further chemical treatment often enhances the adsorbing properties of the material. Activated carbon is usually derived from charcoal.

Medical applications

Activated carbon is used to treat poisonings and overdoses following oral ingestion.

It is thought to bind to poison and prevent its absorption by the gastrointestinal tract. In cases of suspected poisoning, medical personnel administer activated charcoal on the scene or at a hospital’s emergency department. Dosing is usually empirical at 1 gram/kg of body mass (for adolescents or adults, give 50–100 g), usually given only once, but depending on the drug taken, it may be given more than once. In rare situations activated charcoal is used in Intensive Care to filter out harmful drugs from the blood stream of poisoned patients. Activated charcoal has become the treatment of choice for many poisonings, and other decontamination methods such as ipecac-induced emesis or stomach pumping are now used rarely.

While activated carbon is useful in acute poisoning, it has been shown to not be effective in long term accumulation of toxins, such as with the use of toxic herbicides.[7]

Mechanisms of action:

Incorrect application (e.g. into the lungs) results in pulmonary aspiration which can sometimes be fatal if immediate medical treatment is not initiated.[8] The use of activated charcoal is contraindicated when the ingested substance is an acid, an alkali, or a petroleum product.

For pre-hospital (paramedic) use, it comes in plastic tubes or bottles, commonly 12.5 or 25 grams, pre-mixed with water. The trade names include InstaChar, SuperChar, Actidose, Charcodote, and Liqui-Char, but it is commonly called activated charcoal.

Ingestion of activated charcoal prior to consumption of alcoholic beverages appeared to reduce absorption of ethanol into the blood. 5 to 15 milligrams of charcoal per kilogram of body weight taken at the same time as 170 ml of pure ethanol (which equals to about 10 servings of an alcoholic beverage), over the course of one hour, seemed to reduce potential blood alcohol content.[9] Yet other studies showed that this is not the case, and that ethanol blood concentrations were increased because of activated charcoal use.[10]

Charcoal biscuits were sold in England starting in the early 19th century, originally as an antidote to flatulence and stomach trouble.[11]

Tablets or capsules of activated charcoal are used in many countries as an over-the-counter drug to treat diarrheaindigestion, and flatulence.[12] There is some evidence of its effectiveness as a treatment for irritable bowel syndrome (IBS),[13] and to prevent diarrhea in cancer patients who have receivedirinotecan.[14] It can interfere with the absorption of some medications, and lead to unreliable readings in medical tests such as the guaiac card test.[15]Activated charcoal is also used for bowel preparation by reducing intestinal gas content before abdominal radiography to visualize bile and pancreatic andrenal stones. A type of charcoal biscuit has also been marketed as a pet care product.

{Information courtesy Wikipedia}