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PubMed1997

Advantage of high-surface-area charcoal for gastrointestinal decontamination in a human acetaminophen ingestion model.

OBJECTIVE: To compare the abilities of low-surface-area (LSA) vs 2 types of high-surface-area (HSA) activated charcoal given orally to adsorb acetaminophen in the gastrointestinal (GI) tract, as demonstrated by the impact of these agents on the serum levels and area under the curve (AUC) in a simulated human overdose model. METHODS: The main arm of the study was a prospective double-blind crossover trial in which 6 volunteers, serving as their own controls, ingested acetaminophen (50 mg/kg), followed randomly in 10 minutes by either powdered LSA charcoal (950 m2/g) or powdered HSA charcoal (2,000 m2/g) in a charcoal:drug ratio of 8:1. In a second arm of the study, 3 subjects additionally ingested an equal dose of a granular preparation of the HSA charcoal. Serial serum acetaminophen levels were analyzed at various intervals (30, 60, 90, 120, 180, 240, and 300 minutes postingestion), and a 5-hour AUC was calculated. The subjects also rated the charcoal preparations for palatability. RESULTS: Serum acetaminophen levels were lower at all measured times in the groups receiving both forms of the HSA charcoal vs the LSA product. With the powdered HSA charcoal, comparison serum levels were significantly lower at 120 minutes postingestion and all times thereafter (p < 0.05), reaching high significance at 4 and 5 hours (p < 0.001). The subjects receiving the granular HSA charcoal also had consistently lower serum acetaminophen levels than did those receiving the LSA product, and the difference in mean serum levels was significant at the 4- and 5-hour sample (p = 0.012). Compared with the LSA charcoal, at the 4-hour postingestion sample, serum acetaminophen levels were reduced by 44% to 85% by the powdered HSA charcoal. The total AUC for the 5-hour study period was also significantly reduced by the powdered HSA product (p = 0.005) and the granular HSA product (p = 0.043). All the subjects rated the powdered HSA charcoal to be more palatable and easier to drink than the powdered LSA charcoal. CONCLUSION: The surface area of oral activated charcoal is a major determining factor in its ability to limit acetaminophen absorption and to fulfill its adsorptive role in GI decontamination. In a human acetaminophen overdose model, 2 types of HSA charcoal, when compared with equal doses of LSA charcoal, significantly reduced serum levels and total acetaminophen absorption as measured by the AUC.

Absorption↗
PubMed1997

Release of carbon granules from cigarettes with charcoal filters.

OBJECTIVE: To inspect cigarettes with a triple granular filter for charcoal granules on the cut filter surface and, if present, to determine whether the charcoal granules on the filter are released during smoking. DESIGN: 400 Lark cigarettes in 20 packs were examined individually by each of three investigators for the presence of charcoal granules on the cut surface of the cellulose acetate filter. Without removing the cigarettes from the pack, the filters were examined with a stereo zoom microscope for charcoal granules. The percentage of cigarettes that had charcoal granules was defined, and charcoal granules on each filter were counted. Randomly selected cigarettes were then smoked by consenting adult smokers to assess whether the charcoal granules were released during smoking. Lark cigarettes were smoked with a conventional cigarette holder that had been configured to contain an in-line membrane. After smoking, the membrane was analysed microscopically for charcoal granules and other components of the filter that had been released during smoking. RESULTS: Charcoal granules were observed in 79.8% (319/400) of the cigarettes examined. The number of granules per cigarette was 3.3 (SD 3.7). Gaps between the tipping papers--the wrapping papers that surround the filter--were often seen (70%; 242 (71); n = 400 cigarettes). Further, the charcoal cavity was about 60% empty. For all smokers (n = 8/8), charcoal granules were released during smoking. The number of charcoal granules captured on the membranes was 22.5 (16.2) per cigarette. CONCLUSIONS: Charcoal granules are incorporated into cigarette filters to aid in removing toxins in cigarette smoke. In studies of Lark, a popular American cigarette with a charcoal filter, charcoal granules were observed on the filter surface, and were released from the filter when the cigarettes were smoked. During smoking, the toxin-containing charcoal granules are inhaled or ingested. The specific adverse health effects of inhaling or ingesting carbon granules have not been addressed; nevertheless, the smoker, as an educated consumer, should be informed of the possible health risks.

Adult↗
PubMed1998

An in vitro evaluation of fluoxetine adsorption by activated charcoal and desorption upon addition of polyethylene glycol-electrolyte lavage solution.

BACKGROUND: In drug overdoses, treatment with activated charcoal is frequently used because of its adsorptive properties. Recently, whole-bowel irrigation with polyethylene glycol-electrolyte lavage solution has been used as a gastrointestinal decontamination procedure for ingestions of toxins not well adsorbed to activated charcoal and for toxins with a delayed absorption phase, although well adsorbed to activated charcoal. While a combined approach using activated charcoal and whole-bowel irrigation could theoretically enhance the efficacy of both modalities, this improvement remains speculative, since data demonstrating its clinical advantage in overdose treatment are lacking. Fluoxetine, a selective serotonin uptake inhibitor, is one of the most frequently prescribed antidepressants. Fluoxetine is well adsorbed onto activated charcoal. This in vitro investigation was undertaken to study: a) the effect of polyethylene glycol, as well as polyethylene glycol-electrolyte lavage solution, on the adsorption of fluoxetine to laboratory grade-activated charcoal and a commercial activated charcoal formulation (Carbomix powder) in simulated gastric (pH= 1.2) and intestinal (pH=7.2) fluid environment; b) whether the order of polyethylene glycol-electrolyte lavage solution addition would have any effect on the adsorption of fluoxetine to activated charcoal. METHODS: Adsorption of fluoxetine to charcoal in the presence of polyethylene glycol was examined: a) by the simultaneous addition of polyethylene glycol and charcoal to fluoxetine solution and b) by the addition of charcoal to fluoxetine solution and subsequent addition of polyethylene glycol. In both cases, the slurries were incubated at 37 degrees C for 1 hour and filtered. Free fluoxetine concentration was determined in the diluted filtrate by a reversed-phase high-performance liquid chromatography method. RESULTS: The amount of fluoxetine adsorbed to activated charcoal (or Carbomix) was dramatically decreased at gastric and intestinal pH by the presence of polyethylene glycol or polyethylene glycol-electrolyte lavage solution added either concurrently or sequentially to activated charcoal. CONCLUSIONS: In cases of fluoxetine overdose, administration of activated charcoal is recommended, while a combined approach using activated charcoal and whole-bowel irrigation with polyethylene glycol-electrolyte lavage solution is not recommended since it causes a significant desorption of the drug from activated charcoal.

Adsorption↗
PubMed2002

Activated charcoal alone or after gastric lavage: a simulated large paracetamol intoxication.

AIMS: Activated charcoal is now being recommended for patients who have ingested potentially toxic amounts of a poison, where the ingested substance adsorbs to charcoal. Combination therapy with gastric lavage and activated charcoal is widely used, although clinical studies to date have not provided evidence of additional efficacy compared with the use of activated charcoal alone. There are also doubts regarding the efficacy of activated charcoal, when administered more than 1 h after the overdose. The aim of this study was to examine if there was a difference in the effect of the two interventions 1 h post ingestion, and to determine if activated charcoal was effective in reducing the systemic absorption of a drug, when administered 2 h post ingestion. METHODS: We performed a four-limbed randomized cross-over study in 12 volunteers, who 1 h after a standard meal ingested paracetamol 50 mg kg(-1) in 125 mg tablets to mimic real-life, where several factors, such as food, interfere with gastric emptying and thus treatment. The interventions were activated charcoal after 1 h, combination therapy of gastric lavage followed by activated charcoal after 1 h, or activated charcoal after 2 h. Serum paracetamol concentrations were determined by h.p.l.c. Percentage reductions in the area under the curve (AUC) were used to estimate the efficacy of each intervention (paired observations). RESULTS: There was a significant (P<0.005) reduction in the paracetamol AUC with activated charcoal at 1 h (median reduction 66%, 95% confidence intervals 49, 76) compared with controls, and a significant (P<0.01) reduction for gastric lavage followed by activated charcoal at 1 h (median reduction 48.2%, 95% confidence interval 32.4, 63.7) compared with controls. There was no significant difference between the two interventions (95% confidence interval for the difference -3.8, 34.0). Furthermore, we found a significant (P<0.01) reduction in the paracetamol AUC when activated charcoal was administered 2 h after tablet ingestion when compared with controls (median 22.7%, 95% confidence intervals 13.6--34.4). CONCLUSIONS: These results suggest that combination treatment may be no better than activated charcoal alone in patients presenting early after large overdoses. The effect of activated charcoal given 2 h post ingestion is substantially less than at 1 h, emphasizing the importance of early intervention.

Acetaminophen↗
PubMed2004

Activated charcoal administration in a pediatric emergency department.

OBJECTIVES: Activated charcoal is the commonest form of gastrointestinal decontamination offered to potentially poisoned children within United States emergency departments. Our aim was to describe this practice with regard to timing, route of administration, use of flavoring agents, and occurrence of adverse events other than vomiting. METHODS: Descriptive data were prospectively collected from consecutive administrations of single-dose activated charcoal, within an urban, academic pediatric emergency department, over a period of 2.5 years. RESULTS: Two hundred seventy-five subjects were enrolled. The median time elapsed between ingestion and emergency department arrival was 1.2 hours. Although 55% of children were administered charcoal within 1 hour of emergency department presentation, only 7.8% received charcoal within 1 hour of poisoning exposure. Forty-four percent of children younger than 6 years, 50% of 6-year to 12-year olds, and 89% of 12-year to 18-year olds drank the charcoal voluntarily (P < 0.01). Medical staff chose not to offer charcoal orally to 42 asymptomatic children among the 176 subjects under the age of 6 years. Of the 114 young children offered oral charcoal, 36 (32%) refused or were intolerant. Nurses added flavoring agents to the charcoal in 59% of oral administrations, but this act did not enhance observed palatability. Among children younger than 6 years, the median time from first sip to complete ingestion of charcoal slurry was 15 minutes. One pulmonary aspiration event and a case of constipation were noted. CONCLUSIONS: Despite published guidelines, children treated in an emergency department rarely received charcoal within 1 hour of ingestion. Gastric tube administration of charcoal varies by age and is partly subjective in its application. We found no evidence that excipient flavoring of charcoal improved success of administration. Pulmonary aspiration of charcoal, although uncommon, should be considered when assessing the risk of therapy. We offer a report of symptomatic constipation from single-dose charcoal.

Administration, Oral↗
PubMed1999

Effect of activated charcoal alone or given after gastric lavage in reducing the absorption of diazepam, ibuprofen and citalopram.

AIMS: The efficacy of activated charcoal alone, and gastric lavage followed by charcoal in reducing the absorption of diazepam, ibuprofen and citalopram was studied in healthy volunteers. METHODS: In a randomized cross-over study with three phases, nine healthy volunteers were administered single oral doses of 5 mg diazepam, 400 mg ibuprofen and 20 mg citalopram, taken simultaneously after an overnight fast. Thirty minutes later, the subjects were assigned to one of the following treatments: 200 ml water (control), 25 g activated charcoal as a suspension in 200 ml water or gastric lavage followed by 25 g charcoal in suspension given through the lavage tube. Plasma concentrations of diazepam, ibuprofen and citalopram were determined up to 10 h. RESULTS: The AUC(0,10 h) of diazepam was reduced by 27% (P<0.05) by both charcoal alone and charcoal combined with lavage. The increase in plasma diazepam concentration from 0.5 h onwards was prevented by both interventions (P</=0.05), whereas the Cmax of diazepam was not significantly affected by either treatment. The AUC(0, 10 h) of ibuprofen was reduced by 49% (P<0.05) after the combination treatment and by 30% (P<0.05) after charcoal alone, but there was no significant difference between these two treatments. Both charcoal alone and the combination treatment were equally effective in preventing the increase in plasma ibuprofen from 0.5 h onwards (P<0.01). The Cmax of ibuprofen was reduced by 45% (P<0.05) and by 21% (P=NS), respectively. The AUC(0,10 h) of citalopram was reduced by 51% (P<0.05) after both charcoal alone and charcoal combined with lavage, and the Cmax by 52% (P<0.05) and 54% (P<0.05), respectively. The increase in plasma citalopram concentration from 0.5 h onwards was reduced by about 50% (P<0.01) by both interventions. CONCLUSIONS: Activated charcoal alone and charcoal combined with lavage showed similar efficacy in preventing the absorption of diazepam, ibuprofen and citalopram. These results suggest that gastric lavage needs not be routinely performed before administration of charcoal.

Adult↗
PubMed2005

Position paper: Single-dose activated charcoal.

Single-dose activated charcoal therapy involves the oral administration or instillation by nasogastric tube of an aqueous preparation of activated charcoal after the ingestion of a poison. Volunteer studies demonstrate that the effectiveness of activated charcoal decreases with time. Data using at least 50 g of activated charcoal, showed a mean reduction in absorption of 47.3%, 40.07%, 16.5% and 21.13%, when activated charcoal was administered at 30 minutes, 60 minutes, 120 minutes and 180 minutes, respectively, after dosing. There are no satisfactorily designed clinical studies assessing benefit from single-dose activated charcoal to guide the use of this therapy. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, the administration of activated charcoal may be considered if a patient has ingested a potentially toxic amount of a poison (which is known to be adsorbed to charcoal) up to one hour previously. Although volunteer studies demonstrate that the reduction of drug absorption decreases to values of questionable clinical importance when charcoal is administered at times greater than one hour, the potential for benefit after one hour cannot be excluded. There is no evidence that the administration of activated charcoal improves clinical outcome. Unless a patient has an intact or protected airway, the administration of charcoal is contraindicated. A review of the literature since the preparation of the 1997 Single-dose Activated Charcoal Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Adsorption↗
PubMed2005

Scope for regulation of cigarette smoke toxicity: the case for including charcoal filters.

AIM: To compare the emissions toxicity of two manufactured cigarette brands, one with and one without a charcoal filter, in the light of manufacturers' laboratory research findings on the properties of charcoal filters. METHOD: Emissions of Mild Seven charcoal filter brands, regular (labelled '12 mg tar') and Light (labelled '9 mg tar') purchased in 2004, were compared with those of Holiday Extra-mild brand (9 mg tar, acetate filter), purchased in 2002. All emissions were tested under intensive machine smoking conditions by Labstat International Inc., Kitchener, Ontario. RESULTS: The Mild Seven brands contained a small amount of charcoal, its black granules visible against the white acetate filter. The charcoal filter in the brands tested did not reduce toxicity to the extent expected, though they gave significantly lower emissions for the respiratory-toxicants acrolein (14%-17% lower, p 'less than and equal to' 0.01) and formaldehyde (26-37% lower, p 'less than and equal to' 0.01). Reductions were not significant for acetaldehyde, and actually higher for hydrogen cyanide. Overall, estimated cardiovascular-respiratory toxicity was not reduced, whether based on toxicant emissions or the toxicant to nicotine ratios. Of the packet labels, neither tar yield (mg) nor the descriptors 'mild', 'light', or 'extra-mild', or 'charcoal filter' for these three brands was associated with any reduction of the combined respiratory--and cardiovascular toxicity of mainstream smoke, as measured by leading toxicants tested by the intensive method. Previously secret documents from cigarette companies, including British American Tobacco, reported reductions of 75%-80% in hydrogen cyanide, acetaldehyde, acrolein, and formaldehyde in mainstream smoke from addition of charcoal to the filter. We estimated that an effective charcoal filter could reduce a brand's overall relative toxicity score for identifiable toxicant by over 40%. CONCLUSION: Since 1965, major cigarette firms have known from their chemists that many smoke toxicants, including hydrogen cyanide and acrolein, were removable by manufacturing the cigarette with a charcoal filter. To this day, few brands have charcoal filters. The best known, Mild Seven, contained a token charcoal filter only. In neither Japan nor New Zealand did this brand lower cardiovascular toxicant emissions in smoke. In the Smoke-free Environments Act, Government has the power to lower smoke emissions by regulation, but no regulations are in place. The Act does not give power to add filters to cigarettes, but does give power to lower smoke emissions to the level attainable by using a charcoal filter, which could reduce smoke emission toxicity to a large extent. Regulation to require effective charcoal filters is now long overdue.

Carcinogens↗
PubMed1993

Prevalence of sorbitol in multiple-dose activated charcoal regimens in emergency departments.

STUDY OBJECTIVES: To determine the availability and use of premixed activated charcoal in sorbitol preparations during multiple-dose activated charcoal therapy in the emergency department. DESIGN AND SETTING: A prospective telephone survey of all 911 receiving hospitals within the catchment area of one poison center. TYPE OF PARTICIPANTS: Hospital pharmacy supervisors and ED charge nurses. INTERVENTION: Hospital pharmacy supervisors were surveyed about the available preparations of activated charcoal on their hospital's formulary, and ED charge nurses in these same hospitals were surveyed about the prevalence of sorbitol use in multiple-dose activated charcoal regimens. MEASUREMENTS AND MAIN RESULTS: Eleven hospitals (16%) stocked only activated charcoal in sorbitol preparations. Twenty-one hospitals (31%) had both activated charcoal in sorbitol preparations and activated charcoal without sorbitol preparations, and 35 hospitals (52%) had only activated charcoal without sorbitol preparations. Repeat dosing of sorbitol during multiple-dose activated charcoal therapy occurred in 33 of 67 (49%) of the EDs surveyed. CONCLUSION: Sorbitol dosing is often repeated with activated charcoal during multiple-dose activated charcoal therapy in the ED because of the ready availability (and sometimes exclusive availability) of premixed activated charcoal in sorbitol preparations.

Cathartics↗
PubMed2001

Treatment of acetaminophen ingestion with a superactivated charcoal-cola mixture.

STUDY OBJECTIVE: We evaluate the adsorptive capacity of a superactivated charcoal-cola mixture to acetaminophen compared with superactivated charcoal alone. METHODS: This was a triple-arm, prospective, unblinded study of 8 healthy adult human volunteers who ingested 80 mg/kg of acetaminophen. In the control arm of the study, participants ingested acetaminophen alone. In the next arm, acetaminophen was followed by 1 g/kg of superactivated charcoal mixed with water. In the final arm, acetaminophen was followed by 1 g/kg of superactivated charcoal mixed with caffeine-free diet cola. Serum acetaminophen concentrations over 6 hours for each arm were analyzed for area under the time-concentration curve (AUC), peak concentrations, and time to peak concentrations. RESULTS: AUCs were 298.5+/-82.5 mg-h/L (control), 77.1+/-85.2 mg-h/L (superactivated charcoal), and 81.3 +/- 71.8 mg-h/L (superactivated charcoal-cola). Comparison of AUCs by analysis of variance revealed mean square of 128,315.1 between treatments, and residual mean square of 6,405.0, yielding an F ratio of 20.03 (P <.0001). Student-Newman-Keuls pairwise multiple comparison procedure revealed a statistically significant difference in AUC for control versus superactivated charcoal (P <.05) and for control versus superactivated charcoal-cola (P <.05), but not for superactivated charcoal versus superactivated charcoal-cola (P >.05). Time-concentration curves for the 3 study arms were illustrated graphically. CONCLUSION: Combining superactivated charcoal with cola does not limit the adsorptive capacity of superactivated charcoal.

Absorption↗
PubMed1999

Aspiration of activated charcoal elicits an increase in lung microvascular permeability.

BACKGROUND: Gastric decontamination with orally administered activated charcoal is the recommended treatment for many poisonings. However, ingestion of central nervous system depressants resulting in loss of protective airway reflexes may result in pulmonary aspiration of activated charcoal. Although activated charcoal has been reported to be an inert substance, evidence suggests that pulmonary aspiration of charcoal is associated with lung edema formation and pulmonary compromise. This study tested the hypothesis that intratracheal instillation of activated charcoal disrupts the integrity of the lung microvascular barrier. METHODS: The capillary filtration coefficient (Kf,c), a sensitive measure of lung microvascular permeability, was determined isogravimetrically prior to and after intratracheal instillation of activated charcoal 0.04 g/kg (12% weight/vol solution, pH 7.4) or an equal volume of sterile water in isolated, perfused rat lungs. Arterial blood gas analysis was determined prior to and after tracheal instillation of activated charcoal or sterile water in a separate group of animals. RESULTS: Intratracheal instillation of activated charcoal resulted in a significant increase in pulmonary microvascular permeability compared to lungs treated with sterile water or control lungs (delta Kf,c = +0.21 +/- 0.076; -0.014 +/- 0.04; and -0.041 +/- 0.02 mL/min/cm H2O/100 g lung tissue, respectively, p < 0.05 ANOVA). There was no significant difference in baseline blood gases in the 3 experimental groups. There was a significant decrease in arterial Po2, bicarbonate, and pH in animals administered activated charcoal compared to time-matched controls and animals administered sterile water. CONCLUSIONS: Intratracheal instillation of activated charcoal is associated with a significant increase in lung microvascular permeability and arterial blood gas derangements. The effects of activated charcoal on pulmonary microvascular barrier integrity may contribute to the lung edema formation and pulmonary compromise observed following clinical aspiration of activated charcoal.

Animals↗
PubMedDate not supplied

Misadventures with activated charcoal and recommendations for safe use.

OBJECTIVE: To review published reports of adverse effects associated with single- and multiple-dose activated charcoal therapy, and to formulate recommendations for safe use of activated charcoal therapy. DATA SOURCES: A manual search of Index Medicus from 1970 to December 1993 was conducted for English language articles; bibliographies of the resultant articles were also scanned. STUDY SELECTION: Cases were included if they were described in full detail, resulted in significant morbidity or mortality, and uniquely contributed to the formulation of recommendations for safe use of activated charcoal therapy. DATA SYNTHESIS: The major causes of morbidity and mortality secondary to activated charcoal therapy are aspiration of charcoal, gastrointestinal obstruction, and fluid and electrolyte abnormalities. Aspirations have occurred as a result of a number of circumstances that may be avoided. These include use in patients with unprotected airways, use of excessive charcoal dose, administration of inappropriately diluted charcoal, and administration of charcoal in the field. Gastrointestinal obstruction has occurred when multiple doses of activated charcoal have been administered without a cathartic and in cases in which a cathartic was administered if the patient had impaired peristalsis. Fluid and electrolyte abnormalities have occurred secondary to excessive cathartic administration. CONCLUSIONS: Activated charcoal therapy should be used judiciously so that related morbidity and mortality can be prevented. Adequate consideration for the patient's airway protection capability is necessary. Judicious dosing of charcoal and concomitant cathartic therapy, along with adequate monitoring of fluid and electrolyte status, abdominal physical assessment, and clinical condition are all vital to the safe use of activated charcoal therapy.

Charcoal↗
PubMed1991

Theophylline desorption from activated charcoal caused by whole bowel irrigation solution.

Whole bowel irrigation with polyethylene glycol electrolyte lavage solution has been recommended as an adjunct to traditional overdose management. Although combined activated charcoal and whole bowel irrigation could enhance the efficacy of both modalities, this improvement remains largely speculative. An in vitro experiment was designed to determine whether polyethylene glycol electrolyte lavage solution alters the adsorption of theophylline to activated charcoal. Theophylline was agitated with activated charcoal in either water or polyethylene glycol electrolyte lavage solution, at each of three activated charcoal:theophylline ratios; 1:1, 3:1, and 10:1. The concentration in the supernatant was determined by high pressure liquid chromatography, and the maximal adsorptive capacity of activated charcoal for theophylline was calculated from the Langmuir equation. The percent of theophylline adsorbed by activated charcoal in water was 16 +/- 4%, 67 +/- 5%, and 97 +/- 3% for the 1:1, 3:1, and 10:1 ratios, respectively. This was decreased to 17 +/- 5%, 37 +/- 3%, and 62 +/- 2% when polyethylene glycol electrolyte lavage solution was added. A statistical difference (p less than 0.05) occurred at the 3:1 and 10:1 activated charcoal:theophylline ratios. Similarly the maximal adsorptive capacity was decreased 23% from 264 mg/g to 203 mg/g when polyethylene glycol electrolyte lavage solution was added to activated charcoal prior to theophylline. Polyethylene glycol electrolyte lavage solution significantly decreases adsorption of theophylline to activated charcoal in vitro. In vivo studies are required to confirm these findings. If activated charcoal is to be used clinically for theophylline toxicity, the authors suggest the possibility of larger quantities of activated charcoal, and administering activated charcoal in a slurry of water before the initiation of whole bowel irrigation.

Adsorption↗
PubMed1993

An in vitro evaluation of cocaine hydrochloride adsorption by activated charcoal and desorption upon addition of polyethylene glycol electrolyte lavage solution.

Cocaine body-packers and body-stuffers have become a common medical problem. Significant morbidity and mortality result when cocaine is absorbed from the gastrointestinal tract due to cocaine package compromise. The clinical prevention of gastrointestinal absorption of cocaine includes oral activated charcoal and/or whole bowel irrigation with polyethylene glycol--electrolyte lavage solution. This in vitro study investigates the maximal adsorptive capacity of activated charcoal for cocaine at varying activated charcoal:cocaine ratios, at pH 1.2 and pH 7.0, and the effect of polyethylene glycol--electrolyte lavage solution upon this binding. The percent adsorption of cocaine to activated charcoal was significantly better at pH 7.0 for all ratios of activated charcoal:cocaine tested and the maximal adsorptive capacity was 29% greater at pH 7.0 (273 micrograms/mg) than at pH 1.2 (212 micrograms/mg) (p < 0.05). Addition of polyethylene glycol--electrolyte lavage solution to the cocaine-activated charcoal slurry caused significant desorption of cocaine from activated charcoal at all pHs and ratios tested (except the 1:1 ratio at pH 7.0) and was most pronounced at pH 1.2. The addition of polyethylene glycol--electrolyte lavage solution to activated charcoal prior to adding cocaine solution further decreased the adsorption of cocaine to activated charcoal. This difference was significant at both pHs and all ratios tested except the 1:1 ratio at pH 1.2. The maximal adsorptive capacity of activated charcoal for cocaine at pH 1.2 was reduced 75% by pretreatment with polyethylene glycol--electrolyte lavage solution from 212 to 54.2 micrograms/mg, while at pH 7.0 the maximal adsorptive capacity was reduced by 11%, from 273 to 243 micrograms/mg. Polyethylene glycol--electrolyte lavage solution significantly reduces the adsorption of cocaine to activated charcoal particularly if the two are combined at a low pH prior to the addition of cocaine. The in vitro effects suggest that activated charcoal mixed in water should be administered first, followed by the polyethylene glycol--electrolyte lavage solution.

Adsorption↗
PubMed1997

Effect of delayed administration of activated charcoal on the absorption of conventional and slow-release verapamil.

OBJECTIVE: To investigate the effect of simultaneous and delayed administration of activated charcoal on the absorption of two verapamil formulations. METHODS: In the first study, 9 healthy volunteers received the following treatments: 1) verapamil 80 mg (conventional formulation) with 50 mL water only, 2) verapamil 80 mg and 25 g activated charcoal immediately afterwards, and 3) verapamil 80 mg with 50 mL water, followed by 25 g charcoal 2 h after verapamil ingestion. In the second study, 8 healthy volunteers received the following treatments: 1) verapamil 240 mg (slow-release formulation) with 50 mL water only, 2) verapamil slow-release 240 mg and 25 g activated charcoal immediately afterwards, 3) verapamil slow-release 240 mg with 50 mL water, followed by 25 g charcoal 2 h after verapamil ingestion, and 4) verapamil slow-release 240 mg with 50 mL water, followed by 25 g charcoal 4 h later. Plasma verapamil concentrations over 24 h were measured by high performance liquid chromatography. RESULTS: Activated charcoal given immediately after the conventional formulation of verapamil reduced the AUC0-24 h by 99% (p < 0.0005) and the Cmax by 98% (p < 0.0005). When the administration of charcoal was delayed 2 h, no significant change in verapamil absorption was observed. With the slow-release formulation of verapamil, charcoal given immediately after verapamil ingestion reduced the verapamil AUC0-24 h by 86% (p = 0.001) and the Cmax by 82% (p = 0.002). When the administration of charcoal was delayed 2 or 4 h, the AUC0-24 h was reduced by 35% (p = 0.04) and 32% (p = 0.001), respectively, but the Cmax was decreased by 13% (p = NS) and 9% (p = NS) only. CONCLUSIONS: Activated charcoal was effective in preventing absorption of verapamil when it was administered immediately after verapamil ingestion. In the case of slow-release formulation, charcoal reduced verapamil absorption by over 30% even when given 4 h after verapamil.

Administration, Oral↗
PubMed1994

Drug adsorption onto activated charcoal as a means of formulation.

The in vitro adsorption of metoprolol, pindolol, salbutamol, furosemide and clonidine onto activated charcoal was determined. The affinity of the drugs for charcoal decreased with increasing hydrophilicity. Also the rate of adsorption of clonidine onto four charcoal preparations having different particle sizes was studied. The equilibrium was reached rapidly with the charcoal having the smallest particle size, and the adsorption rate decreased as the particle size of the charcoal increased. The desorption of drugs from charcoal was investigated in the Sartorius dissolution apparatus at constant initial drug:charcoal ratio. The desorption had a two-step kinetics. The quantity of the initial rapid release, indicating the development of equilibrium, agreed with the adsorption data determined under the same conditions, except for salbutamol and furosemide at pH 7. The same was true for the Langmuir isotherms determined for adsorption and desorption. The following release step was slow and there were only minor differences between the release rates of the different drugs. The desorption rate (time to reach equilibrium) from the different charcoals was studied using a batch technique. An increase in the particle size of charcoal had, however, only limited sustaining effect on desorption. Although the affinity of the drugs for charcoal was in good agreement with their hydrophobicity, their desorption behavior was not necessarily proportional to their hydrophilicity. The in vitro release of the drugs from charcoal was retarded and was not significantly affected by the charcoal particle size.

Adsorption↗
PubMed2005

Out-of-hospital administration of activated charcoal by emergency medical services.

STUDY OBJECTIVE: We assess the feasibility of activated charcoal provided by emergency medical services (EMS). METHODS: This was a 12-month follow-up study on the feasibility of a newly introduced protocol to administer activated charcoal by EMS to acutely poisoned patients before arrival at the hospital. Administration of activated charcoal (50 g or 1 g/kg orally or by nasogastric tube) was considered in 2,047 patients with acute poisoning. Main outcome measures were success rate and elapsed times in and adverse effects of administering charcoal. RESULTS: Activated charcoal was considered to be an indication for 722 patients (35% of the study population) and was administered to 555 patients. Median elapsed time from poison ingestion to activated charcoal administration was 88 minutes, and median time from activated charcoal administration to hospital arrival was 20 minutes. Activated charcoal was not given to 101 (15.4%) patients, although considered indicated, because of patient refusal (n=72), inability to ingest a charcoal mixture (n=23), technical problems (n=4), or recommendation by the hospital after telephone consultation (n=2). Charcoal caused no reported adverse effects. CONCLUSION: Out-of-hospital activated charcoal administration by EMS is feasible, even in severe poisonings. Adverse events were rare.

Acute Disease↗
PubMed2001

Activated charcoal alone and followed by whole-bowel irrigation in preventing the absorption of sustained-release drugs.

OBJECTIVE: Our objective was to study the effect of activated charcoal on the absorption of sustained-release drugs ingested 1 hour earlier and to examine whether whole-bowel irrigation affects the efficacy of charcoal. METHODS: In this randomized, 3-phase crossover study, 9 healthy subjects received, at the same time, 200 mg carbamazepine, 200 mg theophylline, and 120 mg verapamil. All drugs were given as sustained-release tablets. One hour after taking the tablets, the subjects were assigned to one of the following treatments: 25 g activated charcoal as a suspension, 25 g activated charcoal as a suspension followed by whole-bowel irrigation with polyethylene glycol (PEG) electrolyte lavage solution, or 200 mL water (control). The absorption of the drugs was characterized by using the area under the plasma drug concentration-time curve from time zero to 24 hours [AUC(0-24)], peak plasma concentration (C(max)), C(max) minus the plasma concentration at 1 hour (C(Delta)), and time to peak (t(max)). RESULTS: Activated charcoal alone given 1 hour after drug intake significantly (P <.001) reduced the absorption [AUC(0-24)] of all 3 drugs (by 62%-75%). Also the C(max) and C(Delta) values of these drugs were significantly reduced by charcoal alone. Whole-bowel irrigation did not increase significantly the effect of charcoal on any absorption parameters of the 3 drugs studied. On the contrary, whole-bowel irrigation significantly (P <.01) decreased the efficacy of charcoal with respect to carbamazepine. CONCLUSIONS: Activated charcoal alone given 1 hour after intake of sustained-release drugs was effective in preventing the absorption of all 3 drugs studied. Whole-bowel irrigation may even decrease the efficacy of charcoal if the drug is well adsorbable onto charcoal. However, our study was performed with therapeutic drug doses only. In overdoses their possible effects on gastrointestinal motility may modify the efficacy of decontamination methods.

Adult↗