Charcoal

Common Name(s): Activated charcoal , animal charcoal , charcoal , gas black , lamp black

Uses

Activated charcoal is used as an antidote to poisoning, as an antiflatulent, and as a potential treatment for reducing blood lipid concentrations in patients with uremia and diabetes.

Dosing

The recommended dosage of activated charcoal for children 1 year of age and younger is 10 to 25 g or 0.5 to 1 g/kg; for children 1 to 12 years of age, the recommended dosage is 25 to 50 g or 0.5 to 1 g/kg; and for adolescents and adults, the recommended dosage is 25 to 100 g.

Contraindications

Single-dose activated charcoal is contraindicated in patients with unprotected airways and decreased levels of consciousness who are not intubated. Activated charcoal is also contraindicated if its use increases the risk and severity of aspiration, particularly with low viscosity, aliphatic hydrocarbons (eg, kerosene, lighter fluid, lamp oil). In cases of hydrocarbons with systemic toxicity (ie, benzene) or coingestion with a systemic toxin, charcoal use may be considered. Patients who are at risk of hemorrhage or GI perforation caused by pathology, recent surgery, or medical conditions could be further compromised by single-dose activated charcoal. The presence of activated charcoal in the GI tract may obscure endoscopic visualization, but a corrosive is not an absolute contraindication when charcoal is used for coingested agents that are systemic toxins. The acronym PHAILS represents the following situations in which activated charcoal use is not helpful, requires caution, or is contraindicated: P–Pesticides, petroleum distillated, unprotected airway; H–Hydrocarbons, heavy metals, greater than 1 hour; A–Acids, alkali, alcohols, altered level of consciousness, aspiration risk; I–Iron, ileus, intestinal obstruction; L–Lithium, lack of gag reflex; S–Solvents, seizures.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Emesis is the most common adverse reaction. GI obstruction can develop in patients receiving repeated doses.

Toxicology

Minimal toxicity is associated with the use of charcoal in hemoperfusion.

Charcoal is produced by pyrolysis and high temperature oxidation of organic materials. Animal charcoal is obtained from items such as charred bones, meat, and blood. Activated charcoal is obtained from charred wood or vegetable matter and treated with various substances to increase its adsorptive power. Amorphous carbons (or charcoals) are taken from the incomplete combustion of natural gas, fats, oils, or resins. 1

History

Charcoal has been used for medical purposes for thousands of years. Ancient Egyptian papyri traces the use of charcoal to 1500 BC for the adsorption of odor from rotting wounds. Hindu documents from 450 BC record the use of charcoal and sand filters for the purification of drinking water. Hippocrates and Pliny both describe the use of charcoal to treat epilepsy, cholorosis, and anthrax.

In 1773, the German-Swedish pharmaceutical chemist Carl Scheele recognized the specific adsorptive powers of charcoal with various gases. At a meeting of the French Academy of Sciences in 1831, a pharmacist ingested several times the lethal dose of strychnine with equal amounts of charcoal and survived. However, the Academy members were unimpressed by the demonstration, and charcoal continued to be used for more industrial purposes.

In 1911, the first industrially produced activated charcoal, Eponit , was produced in Austria. Shortly afterward, the use of toxic gases in World War I served as a driving force for the mass production of activated charcoal suitable for respirators. But it was not until 1963, after a review article was published in the Journal of Pediatrics , that activated charcoal became more widely accepted in the management of ingested toxins. 1

Chemistry

The chemistry of charcoal is complex. Although the purest forms essentially consist of all carbon, the small amounts of impurities that remain following combustion of the source material have been difficult to characterize. Medicinal charcoals have been developed with a high surface area-to-weight ratio in order to maximize adsorption capacity.

The adsorptive properties of charcoal can be increased by treatment with substances such as carbon dioxide, oxygen, air, steam, sulfuric acid, zinc chloride, or phosphoric acid (or combinations of these) at high temperatures (500° to 900°C). These materials help remove impurities and reduce the particle size of carbon, allowing more adsorption due to increased surface area. One milliliter of finely subdivided and activated medicinal charcoal has a total surface area of approximately 1,000 m ² . Medicinal or activated charcoal is a fluffy, fine, black, odorless, and tasteless powder without gritty material. It is insoluble in water or other common solvents but may be suspended for a short time after vigorous shaking. 2

Uses and Pharmacology

Acute poisoning antidote
Animal data

Research reveals no animal data regarding the use of charcoal as an acute poisoning antidote.

Clinical data

Activated charcoal has been used in the management of acute toxicity for almost a century. Its large surface area permits the absorption of a variety of complex chemicals, thereby rendering toxic material unavailable for systemic absorption. In addition, charcoal may interrupt the enterohepatic circulation of compounds excreted into the bile. It is usually coadministered with a laxative, which may hasten the elimination of toxins from the GI tract, resulting in diarrhea and more rapid GI transit time. 3

Activated charcoal is used for acute management of a wide variety of poisonings but is particularly useful as an emergency antidote. It is commonly accepted by medical personnel as the antidote of choice for almost all drugs and chemicals, except mineral acids, alkalines, and substances insoluble in aqueous acid solution (eg, tolbutamide). 2

However, charcoal is often underutilized or given in insufficient dosages. On average, it should be administered in at least a 10:1 ratio (charcoal to estimated poison dose). Simultaneous administration of charcoal and the emetic ipecac should be avoided because charcoal may adsorb the ipecac and render it ineffective. The American Academy of Pediatrics and the American Association of Poison Control Centers recommend that ipecac syrup not be stocked at home. Most pharmacies no longer stock ipecac syrup. The dosage range for medicinal charcoal as an antidote is 5 to 50 g with a usual dose of 50 g in adults and 25 g in children. It is administered as an aqueous slurry and may be flavored, although flavoring may reduce its effectiveness.

Numerous reports continue to appear in the medical literature on the usefulness of activated charcoal as an antidote for various poisonings and as a GI decontaminant, but there is controversy as to whether activated charcoal should be used alone or with gastric lavage or ipecac syrup before the activated charcoal treatment. 4 Multiple studies have indicated that a relatively small amount of gastric content is removed by ipecac syrup or gastric lavage, and it has been argued that there are no universal standards for the lavage method, the diameter of the orogastric tube, or the size of the aliquot fluid. Furthermore, lavage fluid temperatures, abdominal massage, and the positioning of patients during these procedures need further study. Some reports caution against the use of activated charcoal alone because it does not adsorb all materials.

A later study commented on the gastric decontamination controversy and focused on acute poisoning emergencies. 5 These researchers suggest the following care in acute poisoning: aggressive support of the cardiovascular, respiratory, and central nervous systems, and appropriate gastric decontamination. They contend that ipecac should be reserved for home use following ingestion of certain toxins and that activated charcoal should replace ipecac for the treatment of mild to moderate poisonings in the emergency room setting. Both gastric lavage and the proper dosage of activated charcoal (adults, 50 to 100 g; children, 25 to 50 g; infants 1 g/kg) should be considered in life-threatening cases. A cathartic should be considered after the administration of activated charcoal.

Volunteer studies suggest that single-dose activated charcoal is more likely to be beneficial if given within 1 hour following ingestion; however, benefit after 1 hour cannot be excluded for poisons with slow gastric motility (eg, anticholinergic substances/drugs, opiates, salicylates). Some authors suggest that activated charcoal is beneficial more than 4 hours following acetaminophen overdose. 1 , 6 It has been demonstrated that the administration of activated charcoal in patients more than 4 hours after ingestion of acetaminophen was associated with reduced incidence of liver injury, as measured by elevated serum transaminases and prothrombin time. 7

There are no satisfactorily designed clinical studies assessing benefit from single-dose activated charcoal. One study of symptomatic patients who received activated charcoal and some form of gastric evacuation (eg, gastric lavage, ipecac, gastric aspiration) showed that patients receiving gastric aspiration and activated charcoal were less likely to be admitted to an intensive care unit. 6

The use of multiple-dose activated charcoal is based on the theory that after absorption, drugs will reenter the gut by passive diffusion if the concentration in the gut is lower than in the blood. Administration of more than 2 doses of activated charcoal may maintain a concentration gradient, causing the drug to continuously pass into the gut where it is adsorbed by the charcoal. Multiple-dose activated charcoal is likely to assist in decreasing absorption when large amounts of the drug are ingested and dissolution is delayed (masses and bezoars [ie, salicylates]), when drugs exhibit a delayed- or prolonged-release phase (ie, enteric coated, sustained release), or when reabsorption can be prevented (enterohepatic circulation of active drug or active metabolites [eg, carbamazepine]). 1

The most effective dose of multiple-dose activated charcoal is unknown, but after the initial appropriate single dose, a dose of 0.25 to 0.5 g/kg every 2 to 6 hours has been recommended. The total dose may be more important than the frequency of administration. Continuous nasogastric administration of activated charcoal can be employed, especially when vomiting occurs. 1

Administration

Activated charcoal can be administered orally as a drink or through a nasogastric tube. If the patient is unconscious, a nasogastric tube with airway protection is mandatory.

Activated charcoal products should be shaken vigorously prior to use to ensure adequate dispersion in the liquid and administration of the prescribed dose. The activated charcoal container should be rinsed thoroughly with water, and the remaining contents administered to the patient. Cathartics, such as sorbitol, mannitol, magnesium citrate, and sodium and magnesium sulfate should never be administered to a poisoned patient, with or without activated charcoal. 6

Blood lipid reducer
Animal data

Research reveals no animal data regarding the use of charcoal as a blood lipid reducer.

Clinical data

It has long been known that uremic patients treated with charcoal hemoperfusion often experience reduction in blood lipid levels, and repeated oral doses of activated charcoal are effective in reducing blood lipid concentrations in uremic 8 and diabetic patients. 9 In a study of hypercholesterolemic patients given 8 g of activated charcoal 3 times a day for 4 weeks, the total cholesterol and low-density lipoprotein (LDL) cholesterol levels decreased 25% and 41%, respectively. High-density lipoprotein (HDL) cholesterol and the ratio of HDL to LDL increased. 10 Mention of this study in the popular press has resulted in an increased interest in the use of oral charcoal for the reduction of blood lipid levels, but there is insufficient evidence to confirm the effect on lipid parameters or to determine an appropriate dose.

Other uses

Capsules of powdered medicinal charcoal are used to relieve the discomfort of abdominal gas and flatulence. The capsules should be taken 2 hours before or 1 hour after any oral medication. As an antiflatulent, the dose range is 520 to 975 mg, taken after meals or at the first sign of discomfort and repeated as needed up to 4.16 g daily. 2

A study was conducted comparing the treatment and reduction of bacteria of chronic wounds (having no clinical signs of local infection) using either activated charcoal silver dressings or cleaning and debridement. Study results demonstrated that activated charcoal silver dressings control infection and reduce healing time, eliminating bacterial barriers. 11

A small study showed that dialysis patients ingesting activated charcoal had a diminished perception of pruritus. This subjective response, assessed by questionnaire, was supported by simultaneous resolution of active skin lesions in 7 of 8 patients. 12

Indoxyl sulfate is one of many uremic toxins. Serum indoxyl sulfate levels are elevated in patients with chronic kidney disease (CKD) and appear to correlate with disease progression. In patients with CKD, a novel charcoal compound, AST-120, in doses of 6.3 and 9 g/day, demonstrated statistically significant reductions in serum indoxyl sulfate levels at week 12. Longer-term studies are needed to determine any prolonged benefits of AST-10. 13

In a small study of 28 patients, the use of activated charcoal in patients receiving irinotecan in cycle 1 resulted in a markedly reduced incidence of grades 3 and 4 diarrhea, compared with patients treated in cycle 2 without activated charcoal. The reduced severity of diarrhea with the use of activated charcoal resulted in a parallel reduction in loperamide consumption and ultimately an increased irinotecan dose intensity in cycle 1, with fewer dose reductions due to diarrhea relative to cycle 2. Evidence of more severe diarrhea in cycle 2 without activated charcoal, despite a lower intensity of delivered irinotecan, supports the usefulness of activated charcoal. 14

Dosage

The recommended dosage of activated charcoal for children 1 year of age and younger is 10 to 25 g or 0.5 to 1 g/kg; for children 1 to 12 years of age, the recommended dosage is 25 to 50 g or 0.5 to 1 g/kg; and for adolescents and adults, the recommended dosage is 25 to 100 g. 1 , 6

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

Because activated charcoal can adsorb drugs in the GI tract, it should be taken 2 hours before or 1 hour after other medications. 15

Adverse Reactions

Emesis is the most common adverse reaction in the administration of activated charcoal, with a reported incidence of 6% to 26%. 1 The American Academy of Clinical Toxicology position statement on single-dose activated charcoal states that the influences of rate and volume of charcoal administration, ingested toxic substances, and premorbid conditions on the incidence of vomiting are unknown. However, in a study in children 18 years of age and younger, previous vomiting and nasogastric tube administration were found to be the most important independent risk factors for vomiting sorbitol content. Large charcoal volume or rapid administration rate did not increase vomiting risk. 16

Of the complications seen with the administration of charcoal, aspiration has the potential to be the most serious. 1 Aspiration of charcoal containing povidone has led to major respiratory complications thought to mainly result from ingestion of gastric contents along with charcoal and not directly from the charcoal itself. 6 There are rare case reports and experimental models of charcoal aspiration causing pulmonary morbidity and mortality. Two experimental studies have demonstrated that instillation of charcoal into the lung can have adverse pathophysiologic consequences. Instillation of charcoal directly into the lungs of rats caused acute changes in pulmonary microvascular permeability and the development of lung edema. In a similar model, obliterative bronchiolitis lesions developed after intrathecal instillation of charcoal. A case of chronic lung disease following the inadvertent administration of activated charcoal into the trachea demonstrated morbidity with daily symptoms that could not be attributed to any other pulmonary pathology. 17

The oral use of charcoal has been associated with adverse reactions, including GI obstruction in the formation of briquettes, which was observed in patients who received repeated doses. 5 , 18 , 19 Other complications following the ingestion of preparations in the form of a charcoal-sorbitol suspension include hypernatremic dehydration 20 and aspiration pneumonia. 21 One disadvantage to the emergency use of oral charcoal is that adsorbed toxins may dissociate from the charcoal and reenter the systemic circulation before the charcoal is excreted. Because charcoal given alone may slow gastric transit time, it is often coadministered with a laxative to hasten its evacuation. It is not clear what effect the long-term ingestion of charcoal preparations may have on vitamin levels. At least one report in pediatric patients focused on pulmonary aspiration of activated charcoal as a complication of its misuse in overdose management. 19

There are case reports in the literature of unusual GI complications, such as esophageal perforation with lavage tube resulting in charcoal mediastinum; GI perforation with charcoal peritoneum; charcoal stercolith with perforation; charcoal bezoar from multiple doses of charcoal causing small bowel obstruction; and a manually disimpacted charcoal briquette that caused constipation after a single dose. There are reports of corneal abrasions caused by charcoal spilling into the eyes while being administered to 2 combative patients. These abrasions were transient and resolved without complications. 1 A case of obstructive laryngitis was reported in a child 2 years of age who received a single dose of activated charcoal nasogastrically. 22

The reported adverse reactions associated with multiple doses of activated charcoal include nausea, vomiting, constipation, ileus, GI obstruction, intestinal perforation, and pulmonary aspiration. A case of acute appendicitis was reported in a patient who received multiple doses of activated charcoal over a 5-day period (total dose, 840 g) for the treatment of carbosulfan poisoning. Pathologic examination of the specimen showed particles of activated charcoal, particularly within the dilated part of the appendicular lumen. In macroscopic and microscopic examination of the surgical specimen, partial obstruction of the appendicular lumen, secondary to activated charcoal accumulation, was evident, but pathological findings of acute appendicitis were not present. 23

Toxicology

Activated charcoal is used in hemoperfusion for the removal of toxins from the blood following acute overdose. In general, there is little toxicity associated with the charcoal component of hemoperfusion.

Bibliography

1. Lapus RM . Activated charcoal for pediatric poisonings: the universal antidote? Curr Opin Pediatr . 2007;19(2):216-222.
2. Gennaro AR, ed. Remington: The Science and Practice of Pharmacy . 19th ed. Easton, PA: Mack Printing Co; 1995.
3. Pond SM . Role of repeated oral doses of activated charcoal in clinical toxicology . Med Toxicol . 1986;1(1):3-11.
4. Harris CR , Kingston R . Gastrointestinal decontamination. Which method is best? Postgrad Med . 1992;92(2):116-122, 125, 128.
5. Krenzelok EP , Dunmire SM . Acute poisoning emergencies. Resolving the gastric decontamination controversy . Postgrad Med . 1992;91(2):179-182, 185-186.
6. Chuka PA, Seger D, Krenzelok EP, Vale JA; American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. Position paper: Single-dose activated charcoal . Clin Toxicol . 2005;42:61-87.
7. Spiller HA , Winter ML , Klein-Schwartz W , Bangh SA . Efficacy of activated charcoal administered more than four hours after acetaminophen overdose . J Emerg Med . 2006;30(1):1-5.
8. Friedman EA . Oral sorbents in uremia: charcoal-induced reduction in plasma lipids . Am J Med . 1977;62(4):541-542.
9. Manis T , Deutsch J , Feinstein EI , Lum GY , Friedman EA . Charcoal sorbent-induced hypolipidemia in uremia and diabetes . Am J Clin Nutr . 1980;33(7):1485-1488.
10. Kuusisto P , Vapaatalo H , Manninen V , Huttunen JK , Neuvonen PJ . Effect of activated charcoal on hypercholesterolaemia . Lancet . 1986;2(8503):366-367.
11. Verdu Soriano J , Rueda López J , Martínez Cuervo F , Soldevilla Agreda J . Effects of an activated charcoal silver dressing on chronic wounds with no clinical signs of infection . J Wound Care . 2004;13(10):419, 421-423.
12. Pederson JA , Matter BJ , Czerwinski AW , Llach F . Relief of idiopathic generalized pruritus in dialysis patients treated with activated oral charcoal . Ann Intern Med . 1980;93(3):446-448.
13. Schulman G . A nexus of progression of chronic kidney disease: charcoal, tryptophan and profibrotic cytokines . Blood Purif . 2006;24(1):143-148.
14. Michael M , Brittain M , Nagai J , et al. Phase II study of activated charcoal to prevent irinotecan-induced diarrhea . J Clin Oncol . 2004;22(21):4410-4417.
15. Charcoal . Drug Facts and Comparisons . factsandcomparisons4.0 [online]. 2008. Wolters Kluwer Health, Inc. Accessed 2008.
16. Osterhoudt KC , Durbin D , Alpern ER , Henretig FM . Risk factors for emesis after therapeutic use of activated charcoal in acutely poisoned children . Pediatrics . 2004;113(4):806-810.
17. Graff GR , Stark J , Berkenbosch JW , Holcomb GW 3rd , Garola RE . Chronic lung disease after activated charcoal aspiration . Pediatrics . 2002;109(5):959-961.
18. Watson WA , Cremer KF , Chapman JA . Gastrointestinal obstruction associated with multiple-dose activated charcoal . J Emerg Med . 1986;4(5):401-407.
19. Anderson IM , Ware C . Syrup of ipecacuanha . Br Med J . 1987;294:578.
20. Farley TA . Severe hypernatremic dehydration after use of an activated charcoal-sorbitol suspension . J Pediatr . 1986;109(4):719-722.
21. Harsch HH . Aspiration of activated charcoal . N Engl J Med . 1986;314(5):318.
22. Donoso A , Linares M , León J , et al. Activated charcoal laryngitis in an intubated patient . Pediatr Emerg Care . 2003;19(6):420-421.
23. Eroglu A , Kucuktulu U , Erciyes N , Turgutalp H . Multiple dose-activated charcoal as a cause of acute appendicitis . J Toxicol Clin Toxicol . 2003;41(1):71-73.

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