| 释义 |
activated charcoal
ac·ti·vat·ed charcoal (ăk′tə-vā′tĭd)n. Highly absorbent carbon obtained by heating granulated charcoal to exhaust contained gases, resulting in a very porous form with a large surface area. It is used chiefly for purifying gases by adsorption, solvent recovery, or deodorization and as an antidote to certain poisons. Also called activated carbon.Thesaurus| Noun | 1. |  activated charcoal - powdered or granular carbon used for purifying by adsorption; given orally (as a slurry) it is an antidote for some kinds of poisonsactivated carbonatomic number 6, carbon, C - an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds |
Activated Charcoal
activated charcoal[′ak·tə‚vād·əd ′char‚kōl] (materials) activated carbon Activated Charcoal or active carbon, obtained from fossil or wood carbon by the removal of resinous substances and the creation of a branching network of pores. With its highly developed surface, activated charcoal adsorbs many different substances. (Hydrocarbons and their derivatives are readily adsorbed; alcohol, ammonia, water, and other polar substances less readily.) Very fine-pored activated charcoal is obtained through thermal decomposition (carbonization without available air) of certain polymers. Pore diameter varies from 10 Å(with specific surface up to 1,000 m2/g) to 1,000 Å (specific surface of about 1 m2/g). Fine-pored activated charcoals adsorb readily, even in the presence of low concentrations and low partial vapor pressures. The phenomenon of capillary condensation is characteristic of large-pored activated charcoals. Activated charcoals are used in antigas equipment as adsorbents and carriers of catalytic and chemisorption-active additives, in industry for the recovery of valuable organic solvents and for the removal of organic impurities from water, in high-vacuum technology to create sorption pumps, and in medicine for the absorption of harmful substances from the gastrointestinal tract, especially in connection with dyspepsia, meteorism, food poisoning, and poisoning by alkaloids and salts of the heavy metals. (For the latter purpose, activated charcoal is also prepared in the form of “Karbolen” tablets.) REFERENCESDubinin, M. M. Fiziko-khimicheskie osnovy sorbtsionnoi tekhniki, 2nd ed. Moscow-Leningrad, 1935.
Metody issledovaniia struktury vysokodispersnykh i poristykh tel, books 1–2. Moscow, 1953–58.
Aref’ev, S. V., and S. P. Maksimov. Zhurnal fizicheskoi khimii, vol. 41, 1967. Page 1565.V. I. SHIMULIS activated charcoal, activated carbonCharcoal obtained by carbonizing organic material, usually in the absence of air; usually in granular or powdered form; highly effective in adsorbing odors in air or in removing colors in solution.activated charcoal
Charcoal, Activated DefinitionActivated charcoal is a fine black odorless and tasteless powder made from wood or other materials that have been exposed to very high temperatures in an airless environment. It is then treated, or activated, to increase its ability to adsorb various substances by reheating with oxidizing gas or other chemicals to break it into a very fine powder. Activated charcoal is pure carbon specially processed to make it highly adsorbent of particles and gases in the body's digestive system.Activated charcoal has often been used since ancient times to cure a variety of ailments including poisoning. Its healing effects have been well documented since as early as 1550 B.C. by the Egyptians. However, charcoal was almost forgotten until 15 years ago when it was rediscovered as a wonderful oral agent to treat most overdoses and toxins.DescriptionActivated charcoal's most important use is for treatment of poisoning. It helps prevent the absorption of most poisons or drugs by the stomach and intestines. In addition to being used for most swallowed poisons in humans, charcoal has been effectively used in dogs, rabbits, rats, and other animals, as well. It can also adsorb gas in the bowels and has been used for the treatment of gas or diarrhea. Charcoal's other uses such as treatment of viruses, bacteria, bacterial toxic byproducts, snake venoms and other substances by adsorption have not been supported by clinical studies. By adding water to the powder to make a paste, activated charcoal can be used as an external application to alleviate pain and itching from bites and stings.Poisons and drug overdosesIt is estimated that one million children accidentally overdose on drugs mistaken as candies or eat, drink, or inhale poisonous household products each year. Infants and toddlers are at the greatest risk for accidental poisoning. Activated charcoal is one of the agents most commonly used for these cases. It can absorb large amounts of poisons quickly. In addition, it is non-toxic, may be stored for a long time, and can be conveniently administered at home. Charcoal works by binding to irritating or toxic substances in the stomach and intestines. This prevents the toxic drug or chemical from spreading throughout the body. The activated charcoal with the toxic substance bound to it is then excreted in the stool without harm to the body. When poisoning is suspected the local poison control center should be contacted for instructions. They may recommend using activated charcoal, which should be available at home so that it can be given to the poisoned child or pet immediately. For severe poisoning, several doses of activated charcoal may be needed.Activated charcoal is also used to induce vomiting in adults who have attempted suicide by taking an overdose of antidepressants, barbiturates, or benzodiazepine tranquilizers.Intestinal disordersIn the past, activated charcoal was a popular remedy for flatus (intestinal gas). Even before the discovery of America by Europeans, Native Americans used powdered charcoal mixed with water to treat an upset stomach. Although charcoal has been recommended as an alternative treatment for flatus, however, studies done in the early 2000s have reported that it is not particularly useful in treating intestinal gas. Such other measures as dietary changes or biofeedback training are more effective in relieving patients' symptoms.Charcoal has also been used to treat such other intestinal disorders as diarrhea, constipation, and cramps. There are few studies to support these uses and there are also concerns that frequent use of charcoal may decrease absorption of essential nutrients, especially in children.Other usesBesides being a general antidote for poisons or remedy for gas, activated charcoal has been used to treat other conditions as well. Based on its ability to adsorb or bind to other substances, charcoal has been effectively used to clean skin wounds and to adsorb waste materials from the gastrointestinal tract. In addition, it has been used to adsorb snake venoms, viruses, bacteria, and harmful materials excreted by bacteria or fungi. However, because of lack of scientific studies, these uses are not recommended. Activated charcoal, when used together with other remedies such as aloe vera, acidophilus, and psyllium, helps to keep symptoms of ulcerative colitis under control. While charcoal shows some anti-aging activity in rats, it is doubtful if it has the same effect in humans.Apart from its medicinal applications, activated charcoal is used by biologists to cool cell suspensions; by public health physicians to filter disease organisms from drinking water; and by environmental scientists to remove organic pollutants from ocean sediments.Recommended dosageFor poisoningActivated charcoal is available without prescription. In cases of accidental poisoning or drug overdose, however, one should call an emergency poison control center, hospital emergency room, or doctor's office for advice. In case that both syrup of ipecac and charcoal are recommended for treatment of the poison, ipecac should be given first. Charcoal should not be given for at least 30 minutes after ipecac or until vomiting from ipecac stops. Activated charcoal is often mixed with a liquid before being swallowed or put into the tube leading to the stomach. Activated charcoal is available as 1.1 oz (33 m) liquid bottles. It is also available in 0.5 oz (15 ml) container sizes and as slurry of charcoal pre-mixed in water or as a container to which water or soda pop can be added. Keeping activated charcoal at home is a good idea so that it can be taken immediately when needed for treatment of poisoning.For acute poisoning, the dosage is as follows:- Infants (under 1 year of age): 1 g/kg.
- Children (1-12 years of age): 15-30 g or 1-2 g/kg with at least 8 oz of water.
- Adults: 30-100 g or 1-2 g/kg with at least 8 oz of water.
For diarrhea or gasA person can take charcoal tablets or capsules with water or sprinkle the content onto foods. The dosage for treatment of gas or diarrhea in adults is 520-975 mg after each meal and up to 5 g per day.PrecautionsParents should keep activated charcoal on hand in case of emergencies.Charcoal should not be given together with syrup of ipecac. The charcoal will adsorb the ipecac. Charcoal should be taken 30 minutes after ipecac or after the vomiting from ipecac stops.Some activated charcoal products contain sorbitol. Sorbitol is a sweetener as well as a laxative, therefore, it may cause severe diarrhea and vomiting. These products should not be used in infants.Charcoal may interfere with the absorption of medications and nutrients such as vitamins or minerals. For uses other than for treatment of poisoning, charcoal should be taken two hours after other medications.Charcoal should not be used to treat poisoning caused by such corrosive products as lye or other strong acids or petroleum products such as gasoline, kerosene, or cleaning fluids. Charcoal may make the condition worse and delay diagnosis and treatment. In addition, charcoal is also not effective if the poison is lithium, cyanide, iron, ethanol, or methanol.Parents should not mix charcoal with chocolate syrup, sherbet, or ice cream, even though it may make charcoal taste better. These foods may prevent charcoal from working properly.Activated charcoal may cause swelling or pain in the stomach. A doctor should be notified immediately. It has been known to cause problems in people with intestinal bleeding, blockage or those people who have had recent surgery. These patients should talk to their doctor before using this product.Charcoal may be less effective in people with slow digestion.Charcoal should not be given for more than three or four days for treatment of diarrhea. Continuing for longer periods may interfere with normal nutrition.Charcoal should not be used in children under three years of age to treat diarrhea or gas.Activated charcoal should be kept out of reach of children.Side effectsCharcoal may cause constipation when taken for a drug overdose or accidental poisoning. A laxative should be taken after the crisis is over.Activated charcoal may cause the stool to turn black. This side effect is to be expected.Patients should consult a doctor if they have pain or swelling of the stomach.InteractionsActivated charcoal should not be mixed with chocolate syrup, ice cream, or sherbet to make it more palatable. These foods prevent the charcoal from working properly.Key termsAdsorption — The binding of a chemical (e.g., drug or poison) to a solid material such as activated charcoal or clay.Antidote — A remedy to counteract a poison or injury.Flatus — Gas or air in the digestive tract.ResourcesBooksBeers, Mark H., MD, and Robert Berkow, MD, editors. "Poisoning." Section 23, Chapter 307. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.Beers, Mark H., MD, and Robert Berkow, MD, editors. "Psychiatric Emergencies." Section 15, Chapter 194. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2002.Cooney, David. Activated Charcoal: Antidote, Remedy, and Health Aid. Brushton, NY: TEACH Services, Inc., 1999.Wilson, Billie A., Margaret T. Shannon, and Carolyn L. Stang. "Charcoal, Activated (Liquid Antidote)." Nurses Drug Guide 2000. Stamford, CT: Appleton & Lange, 2000.PeriodicalsAzpiroz, F., and J. Serra. "Treatment of Excessive Intestinal Gas." Current Treatment Options in Gastroenterology 7 (August 2004): 299-305.Ho, K. T., R. M. Burgess, M. C. Pelletier, et al. "Use of Powdered Coconut Charcoal as a Toxicity Identification and Evaluation Manipulation for Organic Toxicants in Marine Sediments." Environmental Toxicology and Chemistry 23 (September 2004): 2124-2131.Littlejohn, C. "Management of Intentional Overdose in A & E Departments." Nursing Times 100 (August 17, 2004): 38-43.Matsui, T., J. Kajima, and T. Fujino. "Removal Effect of the Water Purifier for Home Use Against Cryptosporidium parvum Oocysts." Journal of Veterinary Medical Science 66 (August 2004): 941-943.Morris, G. J., and H. E. Richens. "Improved Methods for Controlled Rapid Cooling of Cell Suspensions." Cryo Letters 25 (July-August 2004): 265-272.Osterhoudt, K. C., E. R. Alpern, D. Durbin, et al. "Activated Charcoal Administration in a Pediatric Emergency Department." Pediatric Emergency Care 20 (August 2004): 493-498.OrganizationsAmerican Society of Health-System Pharmacists (ASHP). 7272 Wisconsin Avenue, Bethesda, MD 20814. (301) 657-3000. http://www.ashp.org.United States Food and Drug Administration (FDA). 5600 Fishers Lane, Rockville, MD 20857-0001. (888) INFOFDA. http://www.fda.gov.charcoal [chahr´kōl] carbon prepared by charring wood or other organic material.activated charcoal the residue of destructive distillation of various organic materials, treated to increase its adsorptive power; used as a general purpose antidote.activated charcoal Actidose, Actidose-Aqua, Bragg's Medicinal Charcoal (UK), Carbomix (UK), Charcadote (CA), Char-Caps, Charco Caps, EZ-Char Pharmacologic class: Carbon residue Therapeutic class: Antiflatulent, antidote Pregnancy risk category C Action Binds to poisons, toxins, irritants, and drugs, forming a barrier between particulate material and GI mucosa that inhibits absorption of this material in GI tract. As an antiflatulent, reduces intestinal gas volume and relieves related discomfort. Availability Capsules: 260 mg Granules: 15 g/120 ml Liquid: 15 g/120 ml, 50 g/240 ml, 208 mg/1 ml Oral suspension: 12.5 g/60 ml, 15 g/75 ml, 25 g/120 ml, 30 g/120 ml, 50 g/240 ml Powder: 15, 30, 40, 130, 240 g/container Indications and dosages ➣ Poisoning Adults: 25 to 100 g P.O. (or 1 g/kg, or about 10 times the amount of poison ingested) as a suspension in 120 to 240 ml (4 to 8 oz) of water Children: Initially, 1 to 2 g/kg P.O. (or 10 times the amount of poison ingested) as a suspension in 120 to 240 ml (4 to 8 oz) of water ➣ Flatulence Adults: 600 mg to 5 g P.O. as a single dose, or 975 mg to 3.9 g in divided doses Off-label uses • Diarrhea • GI distress • Hypercholesterolemia Contraindications None Precautions Use cautiously in: • patients who have aspirated corrosives or hydrocarbons and are vomiting. Administration See Don't try to give activated charcoal to semiconscious patient. See If signs of aspiration occur, stop giving drug immediately to avoid fatal airway obstruction or infection. • Administer by large-bore nasogastric tube after gastric lavage, as needed. • Give within 30 minutes of poison ingestion when possible. • Mix powder with tap water to form thick syrup. Add fruit juice or flavoring to improve taste. • Be aware that drug inactivates ipecac syrup. • Know that drug is ineffective in poisoning from ethanol, methanol, and iron salts. • Don't give children more than one dose of drug product containing sorbitol (sweetener). • When used for indications other than as antidote, give drug at least 2 hours before or 1 hour after other drugs.  Adverse reactions GI: nausea, vomiting, diarrhea, constipation, black stools, intestinal obstruction Interactions Drug-drug. Acetaminophen, barbiturates, carbamazepine, digitoxin, digoxin, furosemide, glutethimide, hydantoins, methotrexate, nizatidine, phenothiazines, phenylbutazones, propoxyphene, salicylates, sulfonamides, sulfonylurea, tetracycline, theophyllines, tricyclic antidepressants, valproic acid: decreased absorption of these drugs Ipecac syrup: ipecac absorption and inactivation Drug-food. Milk, ice cream, sherbet: decreased absorptive activity of drug Patient monitoring • Monitor patient for constipation. • If patient vomits soon after receiving dose, ask prescriber if dose should be repeated. Patient teaching • Instruct patient to drink six to eight glasses of fluid daily to prevent constipation. • Tell patient that stools will be black as charcoal is excreted from body. • As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and foods mentioned above. ac·ti·vat·ed char·coalresidue from destructive distillation of various organic materials, treated to increase its adsorptive power; used to treat diarrhea, as an antidote to various poisons, and in purification processes in industry and research. Synonym(s): medicinal charcoalactivated charcoal (ăk′tə-vā′tĭd)n. Highly absorbent carbon obtained by heating granulated charcoal to exhaust contained gases, resulting in a very porous form with a large surface area. It is used chiefly for purifying gases by adsorption, solvent recovery, or deodorization and as an antidote to certain poisons. Also called activated carbon.activated charcoal Medicinal charcoal Toxicology AC is used for early management of oral poisoning and is effective against most toxins except mercury, iron, lithium, cyanide; if the drug has an enterohepatic cycle, as do barbiturates, glutethimide, morphine, and other narcotics and tricyclic antidepressants, AC may be repeated for up to 24 hrs; adult dose 50–100 g Therapeutics A carbon residue of destructive distillation–heated to 200ºC-to remove volatile gases of organic materials–eg, bone, wood, resulting in carbonaceous granules–charcoal; AC is effective in removing various substances from a fluid or gas of interestac·ti·vat·ed char·coal (ak'ti-vā-tĕd chahr'kōl) An agent administered orally to prevent intestinal absorption of ingested poisons or drugs taken in excessive dose. activated charcoal A highly absorbent form of carbon used to absorb gas, to deodorize and to inactivate a number of ingested poisons.ac·ti·vat·ed char·coal (ak'ti-vā-tĕd chahr'kōl) Residue from destructive distillation of various organic materials, treated to increase its adsorptive power; used to treat diarrhea, as an antidote to various poisons, and in purification processes in industry and research. AcronymsSeeactiniumactivated charcoal
Synonyms for activated charcoalnoun powdered or granular carbon used for purifying by adsorptionSynonymsRelated Words |