What is activated charcoal?
It was 1831. In front of his distinguished colleagues at the French Academy of Medicine, Professor Touery drank a lethal dose of strychnine and lived to tell the tale. He had combined the deadly poison with activated charcoal.
That's how powerful activated charcoal is as an emergency decontaminant in the gastrointestinal (GI) tract, which includes the stomach and intestines. Activated charcoal is considered to be the most effective single agent available. It is used after a person swallows or absorbs almost any toxic drug or chemical.
- Activated charcoal is estimated to reduce absorption of poisonous substances nearly to 60%.
- It works by binding (adsorbing) chemicals, thus reducing their toxicity (poisonous nature), through the entire length of the stomach and small and large intestines (GI tract).
- Activated charcoal itself is a fine, black powder that is odorless, tasteless, and nontoxic.
- Activated charcoal is often given after the stomach is pumped (gastric lavage). Gastric lavage is only effective immediately after swallowing a toxic substance (within about one-half hour) and does not have effects that reach beyond the stomach as activated charcoal does.
How Activated Charcoal Works
Activated charcoal 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 is often combined with sorbitol (a substance that stimulates the bowels to move, like a laxative) to shorten the amount of time to move through the system and reduce the possibility of constipation. However, to avoid adverse effects, sorbitol is not given with every dose of activated charcoal.
- All efforts should be made to reduce adsorption of severely toxic substances, as activated charcoal does not bind as well with these substances:
- Lithium (Eskalith, Lithobid), strong acids and bases, metals and inorganic minerals such as sodium, iron, lead, arsenic, iodine, fluorine, and boric acid.
- Alcohol (such as ethanol, methanol, isopropyl alcohol, glycols, and acetone)
- Hydrocarbons (such as petroleum distillates and plant hydrocarbons such as pine oil)
- 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.
How Activated Charcoal Is Given
Activated charcoal may be given by mouth to someone who is awake and alert. It is a black liquid drink.
- If the person vomits the drink, another dose will be given through a nasogastric or orogastric tube (a tube inserted through the nose or mouth, down the esophagus and into the stomach).
- If the person is unconscious (or nearly so), an endotracheal intubation (a procedure in which a tube is inserted through the mouth down into the trachea) may be necessary. This allows oxygen to be delivered and helps protect the airway and lungs from gastric content, which minimizes the risk of the person vomiting and choking.
- Activated charcoal is usually given by a doctor. It is not a substance to be used at home. Doctors determine the dose or amount of charcoal to give based on the patient's weight (with special doses for children) and on how much poison was swallowed. There are some doctors who will prescribe charcoal for emergency use in the home. This should only be done under the direct guidance of the doctor or poison control center. In the United States, the direct line to the poison control center is 1-800-222-1222.
- The doctor also determines when and if additional doses are given by monitoring blood levels of the poison. Other symptoms the doctor monitors are nausea and vomiting, abdominal pain, dizziness, and severe heart problems. Multiple doses of activated charcoal can be given if someone swallowed large doses of long-acting, sustained release medications.
- In some cases, if blood levels of the poison remain too high, the doctor may recommend kidney dialysis. Dialysis may be the best way to remove the toxin from the bloodstream.
When Not to Use Activated Charcoal
- Activated charcoal will not be given to people with an obstruction of the intestines or if the person swallowed a corrosive agent, such as a strong acid or alkali.
- Strong acids may "burn" through the lining of the GI tract. Doctors will need to look at the lining with an endoscope - a special instrument designed to look inside the stomach. Activated charcoal is not to be used with this type of poison because it is difficult to see the lining of the GI tract with the scope after charcoal is given.
- Activated charcoal can cause intestinal problems such as constipation, or it can create clumps of foreign material. This situation can be prevented by giving a laxative such as sorbitol to the patient, however, repeated doses with sorbitol may cause excessive diarrhea, dehydration, and chemical imbalance.
- If the patient is fructose intolerant, family members should notify the treating doctor, and sorbitol will not be given with the activated charcoal. Sorbitol is a sugar substitute that acts as a laxative to move the charcoal through the system. Infants younger than one year of age year should not be given sorbitol because it may cause excessive fluid losses.
- If an antidote to a specific type of drug poisoning is given, then the doctor may not give activated charcoal because the drug given as treatment will also be adsorbed. A classic example is an acetaminophen (Tylenol overdose) in which there is a clearly established antidote with acetylcysteine (Mucomyst).
Emergency Home Care for Suspected Poisoning
If you or someone you know has swallowed or breathed a poison and you or they have signs or symptoms, such as nausea, vomiting, pain, trouble breathing, seizure, confusion, or abnormal skin color, you must call either an ambulance, alert your local medical emergency system, or the National Poison Control Center in the United States (1-800-222-1222) for guidance (this number is routed to the poison control center that serves your area).
Place the telephone number (along with police, fire, and 911 or equivalent) near your home phones.
The best approach to poisoning is to identify the toxic substance and call your regional poison control center, or equivalent in your area, or go directly to the nearest Emergency Department.
- Do not induce vomiting or give syrup of Ipecac.
- Ipecac was once used to induce vomiting in poisoned patients for whom there was a chance to get the toxin out of the body. Several advisory bodies such as the American Association of Poison Control Centers and the American Academy of Pediatrics have recommended that Ipecac NOT be used and that it should not even be kept in the home. For more information on this subject go to: http://www.poison.org/prepared/ipecac.asp
- 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 activated charcoal, 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.
- Milk products may decrease the ability of the charcoal to work. Do not attempt these types of home remedies. The best advice is to get the person to an Emergency Department.
- If the person cannot be aroused, is vomiting, or has difficulty breathing, this is a 911 emergency. Bring the container of poison or medicine bottles, if known, to the Emergency Department.