Saline catharsis: effect on aspirin bioavailability in combination with activated charcoal

Systematic review on the use of activated charcoal for gastrointestinal decontamination following acute oral overdose

INTRODUCTION

The use of activated charcoal in poisoning remains both a pillar of modern toxicology and a source of debate. Following the publication of the joint position statements on the use of single-dose and multiple-dose activated charcoal by the American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists, the routine use of activated charcoal declined. Over subsequent years, many new pharmaceuticals became available in modified or alternative-release formulations and additional data on gastric emptying time in poisoning was published, challenging previous assumptions about absorption kinetics. The American Academy of Clinical Toxicology, the European Association of Poison Centres and Clinical Toxicologists and the Asia Pacific Association of Medical Toxicology founded the Clinical Toxicology Recommendations Collaborative to create a framework for evidence-based recommendations for the management of poisoned patients. The activated charcoal workgroup of the Clinical Toxicology Recommendations Collaborative was tasked with reviewing systematically the evidence pertaining to the use of activated charcoal in poisoning in order to update the previous recommendations.

OBJECTIVES

The main objective was: Does oral activated charcoal given to adults or children prevent toxicity or improve clinical outcome and survival of poisoned patients compared to those who do not receive charcoal?  Secondary objectives were to evaluate pharmacokinetic outcomes, the role of cathartics, and adverse events to charcoal administration. This systematic review summarizes the available evidence on the efficacy of activated charcoal.

METHODS

A medical librarian created a systematic search strategy for Medline (Ovid), subsequently translated for Embase (via Ovid), CINAHL (via EBSCO), BIOSIS Previews (via Ovid), Web of Science, Scopus, and the Cochrane Library/DARE. All databases were searched from inception to December 31, 2019. There were no language limitations.  One author screened all citations identified in the search based on predefined inclusion/exclusion criteria. Excluded citations were confirmed by an additional author and remaining articles were obtained in full text and evaluated by at least two authors for inclusion. All authors cross-referenced full-text articles to identify articles missed in the searches. Data from included articles were extracted by the authors on a standardized spreadsheet and two authors used the GRADE methodology to independently assess the quality and risk of bias of each included study.

RESULTS

From 22,950 titles originally identified, the final data set consisted of 296 human studies, 118 animal studies, and 145 in vitro studies. Also included were 71 human and two animal studies that reported adverse events. The quality was judged to have a Low or Very Low GRADE in 469 (83%) of the studies. Ninety studies were judged to be of Moderate or High GRADE. The higher GRADE studies reported on the following drugs: paracetamol (acetaminophen), phenobarbital, carbamazepine, cardiac glycosides (digoxin and oleander), ethanol, iron, salicylates, theophylline, tricyclic antidepressants, and valproate. Data on newer pharmaceuticals not reviewed in the previous American Academy of Clinical Toxicology/European Association of Poison Centres and Clinical Toxicologists statements such as quetiapine, olanzapine, citalopram, and Factor Xa inhibitors were included. No studies on the optimal dosing for either single-dose or multiple-dose activated charcoal were found. In the reviewed clinical data, the time of administration of the first dose of charcoal was beyond one hour in 97% (n = 1006 individuals), beyond two hours in 36% (n = 491 individuals), and beyond 12 h in 4% (n = 43 individuals) whereas the timing of the first dose in controlled studies was within one hour of ingestion in 48% (n = 2359 individuals) and beyond two hours in 36% (n = 484) of individuals.

CONCLUSIONS

This systematic review found heterogenous data. The higher GRADE data was focused on a few select poisonings, while studies that addressed patients with unknown and or mixed ingestions were hampered by low rates of clinically meaningful toxicity or death.  Despite these limitations, they reported a benefit of activated charcoal beyond one hour in many clinical scenarios.

Gastrointestinal decontamination in the acutely poisoned patient

Objective

To define the role of gastrointestinal (GI) decontamination of the poisoned patient.

Data Sources

A computer-based PubMed/MEDLINE search of the literature on GI decontamination in the poisoned patient with cross referencing of sources.

Study Selection and Data Extraction

Clinical, animal and in vitro studies were reviewed for clinical relevance to GI decontamination of the poisoned patient.

Data Synthesis

The literature suggests that previously, widely used, aggressive approaches including the use of ipecac syrup, gastric lavage, and cathartics are now rarely recommended. Whole bowel irrigation is still often recommended for slow-release drugs, metals, and patients who "pack" or "stuff" foreign bodies filled with drugs of abuse, but with little quality data to support it. Activated charcoal (AC), single or multiple doses, was also a previous mainstay of GI decontamination, but the utility of AC is now recognized to be limited and more time dependent than previously practiced. These recommendations have resulted in several treatment guidelines that are mostly based on retrospective analysis, animal studies or small case series, and rarely based on randomized clinical trials.

Conclusions

The current literature supports limited use of GI decontamination of the poisoned patient.

Salicylate poisoning: an evidence-based consensus guideline for out-of-hospital management

A review of U.S. poison center data for 2004 showed over 40,000 exposures to salicylate-containing products. A guideline that determines the conditions for emergency department referral and pre-hospital care could potentially optimize patient outcome, avoid unnecessary emergency department visits, reduce health care costs, and reduce life disruption for patients and caregivers. An evidence-based expert consensus process was used to create the guideline. Relevant articles were abstracted by a trained physician researcher. The first draft of the guideline was created by the lead author. The entire panel discussed and refined the guideline before distribution to secondary reviewers for comment. The panel then made changes based on the secondary review comments. The objective of this guideline is to assist poison center personnel in the appropriate out-of-hospital triage and initial out-of-hospital management of patients with a suspected exposure to salicylates by 1) describing the process by which a specialist in poison information should evaluate an exposure to salicylates, 2) identifying the key decision elements in managing cases of salicylate exposure, 3) providing clear and practical recommendations that reflect the current state of knowledge, and 4) identifying needs for research. This guideline is based on an assessment of current scientific and clinical information. The expert consensus panel recognizes that specific patient care decisions may be at variance with this guideline and are the prerogative of the patient and the health professionals providing care, considering all of the circumstances involved. This guideline does not substitute for clinical judgment. Recommendations are in chronological order of likely clinical use. The grade of recommendation is in parentheses: 1) Patients with stated or suspected self-harm or who are the victims of a potentially malicious administration of a salicylate, should be referred to an emergency department immediately. This referral should be guided by local poison center procedures. In general, this should occur regardless of the dose reported (Grade D). 2) The presence of typical symptoms of salicylate toxicity such as hematemesis, tachypnea, hyperpnea, dyspnea, tinnitus, deafness, lethargy, seizures, unexplained lethargy, or confusion warrants referral to an emergency department for evaluation (Grade C). 3) Patients who exhibit typical symptoms of salicylate toxicity or nonspecific symptoms such as unexplained lethargy, confusion, or dyspnea, which could indicate the development of chronic salicylate toxicity, should be referred to an emergency department (Grade C). 4) Patients without evidence of self-harm should have further evaluation, including determination of the dose, time of ingestion, presence of symptoms, history of other medical conditions, and the presence of co-ingestants. The acute ingestion of more than 150 mg/kg or 6.5 g of aspirin equivalent, whichever is less, warrants referral to an emergency department. Ingestion of greater than a lick or taste of oil of wintergreen (98% methyl salicylate) by children under 6 years of age and more than 4 mL of oil of wintergreen by patients 6 years of age and older could cause systemic salicylate toxicity and warrants referral to an emergency department (Grade C). 5) Do not induce emesis for ingestions of salicylates (Grade D). 6) Consider the out-of-hospital administration of activated charcoal for acute ingestions of a toxic dose if it is immediately available, no contraindications are present, the patient is not vomiting, and local guidelines for its out-of-hospital use are observed. However, do not delay transportation in order to administer activated charcoal (Grade D). 7) Women in the last trimester of pregnancy who ingest below the dose for emergency department referral and do not have other referral conditions should be directed to their primary care physician, obstetrician, or a non-emergent health care facility for evaluation of maternal and fetal risk. Routine referral to an emergency department for immediate care is not required (Grade C). 8) For asymptomatic patients with dermal exposures to methyl salicylate or salicylic acid, the skin should be thoroughly washed with soap and water and the patient can be observed at home for development of symptoms (Grade C). 9) For patients with an ocular exposure of methyl salicylate or salicylic acid, the eye(s) should be irrigated with room-temperature tap water for 15 minutes. If after irrigation the patient is having pain, decreased visual acuity, or persistent irritation, referral for an ophthalmological examination is indicated (Grade D). 10) Poison centers should monitor the onset of symptoms whenever possible by conducting follow-up calls at periodic intervals for approximately 12 hours after ingestion of non-enteric-coated salicylate products, and for approximately 24 hours after the ingestion of enteric-coated aspirin (Grade C).

Position Paper: Cathartics

The administration of a cathartic alone has no role in the management of the poisoned patient and is not recommended as a method of gut decontamination. Experimental data are conflicting regarding the use of cathartics in combination with activated charcoal. No clinical studies have been published to investigate the ability of a cathartic, with or without activated charcoal, to reduce the bioavailability of drugs or to improve the outcome of poisoned patients. Based on available data, the routine use of a cathartic in combination with activated charcoal is not endorsed. If a cathartic is used, it should be limited to a single dose in order to minimize adverse effects of the cathartic. A review of the literature since the preparation of the 1997 Cathartics Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

The role of activated charcoal and gastric emptying in gastrointestinal decontamination: a state-of-the-art review

Gastrointestinal decontamination has been practiced for hundreds of years; however, only in the past few years have data emerged that demonstrate a clinical benefit in some patients. Because most potentially toxic ingestions involve agents that are not toxic in the quantity consumed, the exact circumstances in which decontamination is beneficial and which methods are most beneficial in those circumstances remain important topics of research. Maximum benefit from decontamination is expected in patients who present soon after the ingestion. Unfortunately, many overdose patients present at least 2 hours after taking a medication, when most of the toxin has been absorbed or has moved well into the intestine, beyond the expected reach of gastrointestinal decontamination. Decontamination probably does not contribute to the outcome of many such patients, especially those without symptoms. However, if absorption has been delayed or gastrointestinal motility has been slowed, activated charcoal may reduce the final amount absorbed. The use of activated charcoal in these cases may be beneficial and is associated with few complications. Therefore, administration of activated charcoal is recommended as soon as possible after emergency department presentation, unless the agent and quantity are known to be nontoxic, the agent is known not to adsorb to activated charcoal, or the delay has been so long that absorption is probably complete. The use of gastric emptying in addition to activated charcoal has generated intense debate. Several large comparative studies have failed to demonstrate a benefit of gastric emptying before activated charcoal. Because complications of such 2-step decontamination include a higher rate of intubation, aspiration, and ICU admission, gastric emptying in addition to activated charcoal cannot be considered the routine approach to patients. However, there are several infrequent circumstances in which the data are inadequate to accurately assess the potential benefit of gastric emptying in addition to activated charcoal: symptomatic patients presenting in the first hour after ingestion, symptomatic patients who have ingested agents that slow gastrointestinal motility, patients taking sustained release medications, and those taking massive or life-threatening amounts of medication. These circumstances represent only a small subset of ingestions. In the absence of convincing data about benefit or lack of benefit of gastric emptying for these patients, individual physicians must act on a personal valuation: Is it better to use a treatment that might have some benefit but definitely has some risk or not to use a treatment that has any risk unless there is proven benefit?

Position statement: single-dose activated charcoal. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. Single-dose activated charcoal should not be administered routinely in the management of poisoned patients. Based on volunteer studies, the effectiveness of activated charcoal decreases with time; the greatest benefit is within 1 hour of ingestion. 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 1 hour previously; there are insufficient data to support or exclude its use after 1 hour of ingestion. 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.

Position statement: cathartics. American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists

In preparing this Position Statement, all relevant scientific literature was identified and reviewed critically by acknowledged experts using agreed criteria. Well-conducted clinical and experimental studies were given precedence over anecdotal case reports and abstracts were not usually considered. A draft Position Statement was then produced and subjected to detailed peer review by an international group of clinical toxicologists chosen by the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists. The Position Statement went through multiple drafts before being approved by the Boards of the two societies and being endorsed by other societies. The Position Statement includes a summary statement for ease of use and is supported by detailed documentation which describes the scientific evidence on which the Statement is based. The administration of a cathartic alone has no role in the management of the poisoned patient and is not recommended as a method of gut decontamination. Experimental data are conflicting regarding the use of cathartics in combination with activated charcoal. No clinical studies have been published to investigate the ability of a cathartic, with or without activated charcoal, to reduce the bioavailability of drugs or to improve the outcome of poisoned patients. Based on available data, the routine use of a cathartic in combination with activated charcoal is not endorsed. If a cathartic is used, it should be limited to a single dose in order to minimize adverse effects.

Methamphetamine toxicity prevented by activated charcoal in a mouse model

STUDY OBJECTIVE

To determine the effectiveness of activated charcoal in preventing toxicity from oral methamphetamine HCI.

DESIGN

Randomized, prospective, nonblinded, controlled animal study.

SETTING

Animal care facility.

PARTICIPANTS

CD-1 male mice.

INTERVENTIONS

Mice were given 100 mg/kg methamphetamine HCI (lethal dose 60) in water by oral gavage. Within 1 minute of methamphetamine administration, mice received either 1 g/kg activated charcoal or an equivalent volume of water as control.

MEASUREMENTS AND MAIN RESULTS

Mice were observed for time to onset of symptoms (piloerection, agitation, and tremor) and mortality at 1, 24, and 48 hours. Activated charcoal delayed onset of symptoms (5.53 +/- 1.25 minutes versus 4.27 +/- 1.22 minutes, P < .002) and decreased mortality compared to controls at 1 hour (1 of 20 versus 10 of 20, P < .003) and 24 hours (five of 20 versus 12 of 20, P < .05). There was no difference between groups in mortality at 48 hours.

CONCLUSION

A single dose of activated charcoal given after oral methamphetamine delayed onset of toxicity and decreased early mortality in mice. There was no effect on overall mortality.

Effect of saline cathartics on gastrointestinal transit time of activated charcoal

The effects of saline cathartics on the gastrointestinal transit time of activated charcoal were investigated in six healthy volunteers. The study shows that the mean gastrointestinal transit times of charcoal alone were 29.3 h and 24.4, 15.4, 17.3 and 17.5 h with sodium chloride, sodium sulphate, magnesium sulphate alone and Andrew's Liver Salt respectively. Some volunteers complained of slight abdominal discomfort in all the phases except the Andrew's Liver Salt phase.

Pediatric gastrointestinal decontamination in acute toxin ingestion

The appropriate implementation of the various modalities of gastrointestinal (GI) decontamination is critical in the management of the pediatric patient who is examined in the emergency department or private office after an acute ingestion. Gastrointestinal decontamination includes gastric lavage, syrup of ipecac, activated charcoal, and whole bowel irrigation. Clinical studies have delineated the role and efficacy of these procedures. Trends in GI decontamination place less emphasis on ipecac and gastric lavage and more emphasis on activated charcoal alone in the patient with a mild overdose. Gastric lavage is indicated in serious ingestion and is most effective if done soon after the exposure. Whole bowel irrigation is the newest addition and has important clinical use in the treatment of serious iron ingestions as well as in older adolescent cocaine body suffers and packers. Indications and contraindications of the various forms of GI decontamination are discussed and relevant clinical studies are reviewed.

Selection of activated charcoal products for the treatment of poisonings

OBJECTIVE

To determine if differences exist among currently available activated charcoal products, and if an evaluation of risk versus benefit provides a guide to product selection.

DESIGN

National survey by mail.

PARTICIPANTS

US manufacturers of activated charcoal products.

RESULTS

Six companies market activated charcoal products in ready-to-use containers. The products differ in surface area of charcoal, sorbitol content, and packaging (aqueous or powdered form). No significant differences were noted in the cost of 25- to 30-g units or efficacy based on surface area of activated charcoal. The addition of sorbitol to activated charcoal, particularly at high concentrations, increases the incidence of adverse effects, especially in children.

CONCLUSIONS

Although differences do exist among currently marketed activated charcoal products, the clinical significance of these variations is unknown. Based on an evaluation of risks and benefits, any activated charcoal product that does not contain sorbitol appears to be a suitable choice for treating poisoning victims.

The preadministration of activated charcoal and aspirin absorption

There is little information describing the effects of activated charcoal preadministration on drug absorption. This study was undertaken to determine the effect of activated charcoal preadministration at two different times on aspirin absorption. Fifteen volunteer subjects completed three study phases: 1) 975 mg aspirin alone, 2) 975 mg aspirin 30 min after 10 g activated charcoal, and 3) 975 mg aspirin 60 min after 10 g activated charcoal. Urine was collected for 48 h after the initiation of each study phase, and total aspirin recovery determined by HPLC. The aspirin recovery was 88.8% +/- 4.5% for the control phase, and 84.8% +/- 9.4% (Phase 1) and 85.8% +/- 12.6% (Phase 2) for the activated charcoal treatments (p > 0.05). These results suggest that activated charcoal administered 30 and 60 min prior to drug ingestion has little effect on drug absorption. Further studies of the effect of charcoal preadministration on the absorption of other drugs may provide useful information regarding factors important in determining activated charcoal efficacy.

Role of repeated doses of oral activated charcoal in the treatment of acute intoxications

While single dose activated charcoal is effective in preventing drug absorption, repeated doses not only prevent absorption but also can increase systemic drug clearance. The mechanism for the latter effect may involve interruption of enterohepatic recycling and/or promotion of drug exsorption from the systemic circulation into the gut lumen. A comprehensive review of reported studies in volunteer subjects and overdose patients showed that repeated dose activated charcoal markedly decreased the half-life and/or increased the clearance of a wide range of drugs. Side-effects of the treatment were infrequent, but included aspiration pneumonia, diarrhoea and constipation. The addition of laxatives to repeated dose charcoal treatment did not offer any significant increase in drug clearance and is not recommended. It is suggested that the optimal regimen for the use of repeat dose activated charcoal in acute drug intoxications is an initial dose of 75-100 g, followed by 50 g every 4 hours until the risks of systemic drug toxicity are reduced to an acceptable level.

Contribution of sorbitol combined with activated charcoal in prevention of salicylate absorption

The use of cathartics and activated charcoal in treating toxic ingestions has become a standard treatment modality. Sorbitol has been shown to be the most rapidly acting cathartic, but its therapeutic significance has been debated. Using a previously described aspirin overdose model, ten healthy volunteers participated in a crossover design study that investigated the effect of activated charcoal alone versus that of activated charcoal and sorbitol in preventing salicylate absorption. In phase 1 of the study, subjects consumed 2.5 g aspirin followed by 25 g activated charcoal one hour later. Urine was collected for 48 hours and analyzed for quantitative salicylate metabolites. Phase 2 was identical except that 1.5 g/kg sorbitol was consumed with the activated charcoal. The mean amount of aspirin absorbed without the use of sorbitol was 1.26 +/- 0.15 g, whereas the mean absorption was 0.912 +/- 0.18 g with the addition of sorbitol. This is a 28% decrease in absorption of salicylates attributable to the use of sorbitol. The difference is significant at P less than .05 by the paired Student's t test. This study demonstrates that the addition of sorbitol significantly decreases drug absorption in a simulated drug overdose model. Effects on absorption in actual overdose situations and on patient outcome should be the subjects of further study.

Effects of magnesium citrate and clidinium bromide on the excretion of activated charcoal in normal subjects

The efficacy of cathartics in shortening the gastrointestinal transit time of activate charcoal (AC) in the presence of drugs that alter gastrointestinal motility has not been determined. We evaluated the effects of magnesium citrate (MC) on the excretion of activated charcoal in healthy volunteers alone and with concurrent administration of the anticholinergic drug clidinium bromide. Forty subjects were randomized to clidinium bromide 5 mg or placebo capsule (PC), followed by activated charcoal 15 g and magnesium citrate or a placebo liquid (PL). The onset and duration of excretion of activated charcoal were noted. Mean onset times for activated charcoal were: group I (CB, MC) 4.5 +/- 2.1 h; group II (CB, PL) 17.0 +/- 10.0 h; group III (PC, MC) 6.3 +/- 5.8 h; and group IV (PC, PL) 20.6 +/- 8.4 h. The onset of excretion of activated charcoal was statistically different in both magnesium citrate groups as compared with the placebo liquid groups. The duration of activated charcoal in the stool was similar among the groups. The addition of clidinium bromide did not appear to affect gastrointestinal transit time. These results support previous studies of the effects of cathartics on the excretion of activated charcoal, and suggest that cathartic efficacy is not inhibited by anticholinergic drugs when used in therapeutic doses.

Effect of whole-bowel irrigation on the antidotal efficacy of oral activated charcoal

Whole-bowel irrigation was studied in three volunteer subjects and compared with oral activated charcoal as a gastrointestinal decontamination procedure for acute drug overdose. The volunteer subjects were given 650 mg aspirin and were assigned randomly to the following treatment groups: 24-hour urine collection only; immediate whole-bowel irrigation with a polyethylene glycol solution; 50 g oral activated charcoal followed by whole-bowel irrigation; and oral activated charcoal alone. The cumulative 24-hour urinary salicylate excretion was measured in each trial. Catharsis was achieved rapidly with whole-bowel irrigation. Oral activated charcoal without catharsis was most effective in decreasing aspirin absorption (P = .011). These results do not support the routine use of a cathartic in combination with oral activated charcoal.

Oral activated charcoal in the treatment of intoxications. Role of single and repeated doses

Activated charcoal has an ability to adsorb a wide variety of substances. This property can be applied to prevent the gastrointestinal absorption of various drugs and toxins and to increase their elimination, even after systemic absorption. Single doses of oral activated charcoal effectively prevent the gastrointestinal absorption of most drugs and toxins present in the stomach at the time of charcoal administration. Known exceptions are alcohols, cyanide, and metals such as iron and lithium. In general, activated charcoal is more effective than gastric emptying. However, if the amount of drug or poison ingested is very large or if its affinity to charcoal is poor, the adsorption capacity of activated charcoal can be saturated. In such cases properly performed gastric emptying is likely to be more effective than charcoal alone. Repeated dosing with oral activated charcoal enhances the elimination of many toxicologically significant agents, e.g. aspirin, carbamazepine, dapsone, dextropropoxyphene, cardiac glycosides, meprobamate, phenobarbitone, phenytoin and theophylline. It also accelerates the elimination of many industrial and environmental intoxicants. In acute intoxications 50 to 100g activated charcoal should be administered to adult patients (to children, about 1 g/kg) as soon as possible. The exceptions are patients poisoned with caustic alkalis or acids which will immediately cause local tissue damages. To avoid delays in charcoal administration, activated charcoal should be a part of first-aid kits both at home and at work. The 'blind' administration of charcoal neither prevents later gastric emptying nor does it cause serious adverse effects provided that pulmonary aspiration in obtunded patients is prevented. In severe acute poisonings oral activated charcoal should be administered repeatedly, e.g. 20 to 50g at intervals of 4 to 6 hours, until recovery or until plasma drug concentrations have fallen to non-toxic levels. In addition to increasing the elimination of many drugs and toxins even after their systemic absorption, repeated doses of charcoal also reduce the risk of desorbing from the charcoal-toxin complex as the complex passes through the gastrointestinal tract. Charcoal will not increase the elimination of all substances taken. However, as the drug history in acute intoxications is often unreliable, repeated doses of oral activated charcoal in severe intoxications seem to be justified unless the toxicological laboratory has identified the causative agent as not being prone to adsorption by charcoal. The role of repeated doses of oral activated charcoal in chronic intoxication has not been clearly defined.(ABSTRACT TRUNCATED AT 400 WORDS)

Effectiveness of commercially available aqueous activated charcoal products

A human research project was conducted to compare the relative effectiveness of five commercially available aqueous activated charcoal products in 25-g amounts--Acta-Char, Actidose-Aqua, Insta-Char, Liqui-Char, and Super-Char. Seven healthy adult human fasting volunteers participated. The study was double-blinded and subjects served as their own controls. Aspirin 2,592 mg was administered to each subject in the control phase to establish baseline aspirin absorption as measured by serial serum salicylate levels. During each of the five study phases 2,592 mg aspirin and a specific brand of activated charcoal were administered to the subjects and serial serum salicylate levels were drawn. Aspirin absorption was calculated using the trapezoidal rule for measuring the area under the concentration-time curve. Total aspirin absorption was reduced as follows: Super-Char, 57.76%; Actidose-Aqua, 50.42%; Insta-Char, 39.55%; Liqui-Char, 33.40%; and Acta-Char, 27.46%. Although there were large apparent differences in the adsorptive capacities of the products, the only statistically significant difference was between Super-Char and Acta-Char. The failure to show statistical differences in the face of large apparent differences may have been a reflection of type II beta error due to the small sample size. The most common factor responsible for the apparent differences in the adsorptive capacities of the products was most likely the surface area of the activated charcoals that were used. The higher surface area products, Super-Char (3,150 m2/g) and Actidose-Aqua (1,500 m2/g) prevented the absorption of aspirin more effectively than the other three products that had surface areas of 950 m2/g.

Efficacy of ipecac-induced emesis, orogastric lavage, and activated charcoal for acute drug overdose

The efficacy of ipecac-induced emesis, large-bore orogastric lavage, and activated charcoal as gastrointestinal decontamination procedures after acute drug overdose is unknown. Using an ampicillin overdose model, these three procedures were compared with one another and to a control ingestion in ten human volunteers. Serial serum ampicillin levels were used to compute the areas under the concentration vs time curves (AUC) for each study. The reductions of ampicillin absorption compared to control were as follows: orogastric lavage 32% (NS), ipecac-induced emesis 38% (P less than .01), and activated charcoal 57% (P less than .01). This model examines each intervention in a mutually exclusive fashion. It supports activated charcoal administration as the primary gastrointestinal decontamination procedure after acute drug overdose.

Role of extracorporeal drug removal in acute theophylline poisoning. A review

Theophylline, with its narrow therapeutic margin, is a common cause of iatrogenic and deliberate overdose. Most cases of self-poisoning are with sustained release preparations, with peak concentrations occurring up to 12 or more hours after overdose. Toxic symptoms are often seen at concentrations above 15 mg/L. Theophylline is metabolised within the cytochrome P-450 system, with an average total body clearance of 50 to 60 ml/min. Clearance is, however, affected by many factors such as other drugs or disease, and in overdose zero order kinetics may result in prolonged half-lives. Toxicity is characterised by agitation, tremor, nausea, vomiting, abdominal pains, seizures, and tachyarrhythmias. Hypokalaemia and metabolic acidosis are more profound in acute toxicity, and hypercalcaemia is usually present. Seizures occur at lower concentrations after chronic over-medication than after acute overdose. Gastric lavage should be performed in all patients presenting early, and an oral multiple dose charcoal regimen started with 50 to 100g charcoal, repeating with 50g doses and checking theophylline concentrations at 2- to 4-hour intervals. Multiple dose charcoal can be expected to double the clearance of theophylline, being as effective as a haemodialysis. Of the invasive techniques available, charcoal haemoperfusion is the most effective, increasing clearance 4- to 6-fold. Supportive care is particularly important. The aggressive supplementation of potassium, treatment of emesis with droperidol and ranitidine, and treatment of tachyarrhythmias and hypotension (possibly with propranolol), together with oral multiple dose charcoal may obviate the need for haemoperfusion. Seizures suggest increased morbidity and mortality. Charcoal haemoperfusion should be considered if plasma concentrations are greater than 100 mg/L in an acute intoxication or greater than 60 mg/L in a chronic intoxication. The decision to haemoperfuse should not be based on plasma concentrations alone, but an overall evaluation of the patient's laboratory and clinical status.

Effect of purgatives on antidotal efficacy of oral activated charcoal

The effects of purgatives on the antidotal efficacy of oral activated charcoal were studied in seven volunteer subjects. The volunteer subjects were given 1000 mg of aspirin, 100 mg of atenolol and 50 mg of phenylpropanolamine with 100 ml of water on an empty stomach and were assigned randomly to the following treatment groups: after 5 min 150 ml of water, after 5 min 25 g of charcoal, after 5 min charcoal orally with 20 mg of metoclopramide rectally, followed by 10 mg of bisacodyl rectally 3 h afterwards, after 5 min charcoal with 250 ml of magnesium citrate USP and after 60 min charcoal with metoclopramide followed by bisacodyl 3 h thereafter. The plasma concentrations (0-24 h) and the cumulative urinary excretion (0-72 h) of salicylates, atenolol and phenylpropanolamine were measured. Both magnesium citrate and metoclopramide combined with bisacodyl hastened the gastrointestinal transit but magnesium citrate was more effective. Charcoal alone reduced the absorption of aspirin and phenylpropanolamine by about 50% and that of atenolol by about 95%. The purgatives did not modify significantly the efficacy of charcoal. When the antidotal treatment was delayed by 60 min its efficacy was reduced to some extent, possibly depending on the pharmaceutical formulation of the test drugs. The present results do not support the routine use of purgatives in combination with activated charcoal. In some instances, however, their use may promote the evacuation of, for example, depot formulations from the gastrointestinal tract and thus have a beneficial effect together with activated charcoal in reducing absorption.

Saline cathartics and the adsorptive capacity of activated charcoal for aspirin

The influence of three saline cathartics and tap water on the adsorption characteristics of activated charcoal for aspirin was studied with adsorption isotherms. Compared with distilled water, the adsorptive capacity of activated charcoal for aspirin was not significantly altered by magnesium sulfate, sodium sulfate, or tap water. Pretreating activated charcoal with magnesium citrate reduced the adsorptive capacity of activated charcoal by 15% (P less than .05). There was no significant correlation between mean pH values and adsorptive capacities in all test solutions. None of the saline cathartic solutions apparently displaced aspirin that already was adsorbed by activated charcoal.

Gastrointestinal decontamination for acute poisoning

Gastric decontamination remains an important element in the therapy of pediatric poisoning; however, several issues remain unresolved. Additional studies, particularly in the clinical setting, are necessary to establish optimal therapeutic recommendations. Based on the data presented in this review, the following general recommendations can be made for gastric decontamination in children: If it is necessary to remove an ingested toxin, ipecac syrup is the preferred method if contraindications to its use are not present. The dose should be 30 ml in children older than 1 year of age and 10 ml in children 6 to 12 months of age. Pending further studies, the use of emetics in children younger than 6 months of age cannot be generally recommended, particularly in the home setting. Gastric lavage should be considered to be of very limited use in pediatric patients. Lavage using small nasogastric tubes, except under special circumstances, is nonproductive and cannot be advocated. If it must be used, a large-bore orogastric hose should be used. Administration of activated charcoal prior to lavage should be considered. In situations in which prompt induction of emesis is not possible or contraindications to emesis exist, activated charcoal followed by, or mixed with, a cathartic (preferably sorbitol) should be used as an alternative to removal of gastric contents. Patients with significant symptoms from ingestion requiring hospitalization should receive repeat doses of charcoal and cathartic until symptoms resolve. Activated charcoal should be given in conjunction with other appropriate therapies. Although the data to substantiate this recommendation are limited, particularly in pediatric patients, it is a benign therapy that holds promise of increasing drug elimination.

Gastric emptying. Risk versus benefit in the treatment of acute poisoning

This review examines the various clinical options used to elicit gastric emptying, viz. drug-induced emesis, mechanical pharyngeal stimulation, gastric lavage, and catharsis. Apomorphine and syrup of ipecac are the 2 drugs most frequently used for induction of emesis. Both agents act centrally and, in addition, syrup of ipecac has a peripheral action. Toxins ingested or foods previously eaten may inhibit or enhance emetic action by interfering with mediating and conducting mechanisms. Studies indicate that both syrup of ipecac and apomorphine are similarly effective in inducing emesis; however, apomorphine has a shorter reaction time compared with syrup of ipecac. There are more risks involved with the use of apomorphine, since it causes central nervous system and respiratory depression. Syrup of ipecac has been shown to be relatively safe when used in its recommended dosage for emesis. However, several toxicities have been reported with the use of the fluid extract of ipecac. Emesis is contraindicated in patients who are obtunded or comatose, and in patients who have ingested stimulants, some hydrocarbons, or corrosives. Mechanical pharyngeal stimulation is a simple method of inducing emesis; however, it is often unsuccessful and rarely recovers a significant portion of the gastric contents. Gastric lavage is a procedure which has been relied upon for over a century. Its effectiveness is dependent on the nature, form, and dosage of the poison, latency between time of ingestion and lavage, and technique. In clinical experiments studying gastric lavage, it has been noted that the procedure is most beneficial 1 to 2 hours postingestion for the majority of poison ingestions. Lavage also provides an excellent route for activated charcoal and selected antidotes. Gastric lavage may pose several risks to the patient, including obstruction and contamination of the airways and oesophageal damage. Contraindications for gastric lavage are similar to those for emesis except that it may be safer to use in obtunded, comatose, or uncooperative patients. Cathartics used during initial poisoning therapy are usually the saline cathartics. They elicit an osmotic reaction in the small intestine which results in increased intraluminal fluid bulk, hyperperistalsis, and subsequent propulsion of contents. Cathartics have also been shown to stimulate the secretion of cholecystokinin, which is thought to have similar effects on the intestine. Cathartics have not been shown to significantly enhance drug elimination from the gastrointestinal tract.(ABSTRACT TRUNCATED AT 400 WORDS)

Gastrointestinal transit times of cathartics combined with charcoal

Oral activated charcoal usually is administered in toxic ingestions along with a cathartic. A study was done in volunteers to determine the rapidity of gastrointestinal transit when activated charcoal was administered with various cathartics. A control of activated charcoal was compared to the gastrointestinal transit times of activated charcoal plus the cathartics magnesium citrate, magnesium sulfate, or sorbitol. Activated charcoal alone produced a mean transit time of 23.5 hours; magnesium citrate catharsis occurred in 4.2 hours, magnesium sulfate catharsis occurred in 9.3 hours, and sorbitol catharsis occurred in 0.9 hours. Sorbitol clearly was the most rapidly acting cathartic.

Salicylate-induced pulmonary edema: clinical characteristics in children

A five-year retrospective study of pediatric salicylate intoxications (serum level greater than 300 micrograms/ml) revealed that 2/20 patients developed salicylate induced pulmonary edema. These patients had significantly higher initial anion gaps (P less than 0.02) and serum salicylate determinations (P less than 0.001) and tended to be younger with lower initial serum potassium and arterial carbon dioxide measurements. Both patients in the salicylate-induced pulmonary edema group died, whereas none in the non-pulmonary edema group died. Unlike other reports, these data suggest that pulmonary edema is not rare in severe pediatric salicylate ingestion and correlates with high serum salicylate levels and anion gaps. Early, aggressive detoxification, supportive therapy, and hemodynamic monitoring would appear to be indicated in these patients.

Evaluation of activated charcoal-sodium sulfate combination for inhibition of acetaminophen absorption and repletion of inorganic sulfate

Activated charcoal is an effective inhibitor of acetaminophen absorption while sodium sulfate can prevent the depletion of endogenous inorganic sulfate associated with the formation of acetaminophen sulfate. Administration of activated charcoal plus sodium sulfate soon after acetaminophen overdose may reduce acetaminophen absorption and facilitate the elimination of absorbed acetaminophen by providing sufficient sulfate ion for rapid sulfation of the drug. This investigation was designed to determine if sodium sulfate modifies the inhibitory effect of activated charcoal on acetaminophen absorption or if activated charcoal affects the absorption of sodium sulfate. Eight normal adults received, on separate occasions, 1 g acetaminophen, 1 g acetaminophen and 18 g sodium sulfate (decahydrate), 1 g acetaminophen with 10 g activated charcoal and 1 g acetaminophen, with 10 g activated charcoal and 18 g sodium sulfate, in random order. Urine was collected for 48 hours and assayed for acetaminophen and its major metabolites and for inorganic sulfate. The results confirm that activated charcoal can reduce acetaminophen absorption and show that oral administration of activated charcoal with sodium sulfate does not alter the inhibitory effect of activated charcoal on acetaminophen absorption or the bioavailability of the sulfate. A combination of activated charcoal and sodium sulfate may therefore be useful for the initial management of acetaminophen overdose.