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

The Role of Activated Charcoal in Prehospital Care

Background

Administration of a single-dose activated charcoal (SDAC) is an effective method used for gastric decontamination and for other types of poisoning and overdose. This is only true when given within the first hour of poison ingestion as the effectivity of SDAC reduces over time. In addition, generally, not all patients are able to avail treatment within the specified period. Hence, multi-dose activated charcoal is regarded as a solution to a delayed process, although, no proof outweighs the use of SDAC.

Objective

This study aimed to review and assess the adequacy of the past and current use of AC. The author also aimed to offer recommendations believed to be the best method to consider for prehospital care.

Methods

The author conducted 6,337 online literature searches for this review, wherein seven papers met eligibility criteria for inclusion and analysis.

Results

In this review, routine administration of AC in poisoning was found not related to the duration of hospital stay nor any other subsequent outcomes following poison ingestion. Further, this review did not establish that administration of AC could improve patient's clinical outcome. Further research and clinical trials is required to determine the efficacy of this therapy to appropriate patients in the prehospital setting.

Conclusion

Activated charcoal can be used to treat highly acute to life-threatening poisoning if it is administered within the first hour of ingestion. Further studies would be necessary to investigate if this would affect clinical outcome..

Alginate-coated activated charcoal enhances fecal excretion of 2,3,7,8-tetrachlorodibenzo-p-dioxin in mice, with fewer side effects than uncoated one

Activated charcoal (AC) is a potential candidate antidote against dioxins. However, it is difficult to take AC as a supplement on a daily basis, because its long-term ingestion causes side effects such as constipation and deficiency of fat-soluble essential nutrients and hypocholesterolemia. Alginate-coated AC, termed Health Carbon (HC), was developed to decrease the side effects of AC, but its pharmacological effects, including side effects, remains unclear. Here, we show that HC enhanced fecal excretion of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and decreased some side effects of unmodified AC, such as hypocholesterolemia, in male mice. Basal diet mixed with HC or unmodified AC at various concentrations was fed to mice for 16 days following a single intraperitoneal administration of [3H]TCDD. Both HC and unmodified AC at 3% or more significantly increased fecal excretion of [3H]TCDD in comparison with the control basal diet. Consistent with this, [3H]TCDD radioactivity in the liver-a major TCDD storage organ-was markedly decreased by HC at concentrations of 3% and 10%. In an examination of potential side effects, unmodified AC at 10% or more caused significant body weight reduction and at 20% caused significant hypocholesterolemia. In contrast, HC caused weight gain reduction only at a concentration of 20%, and there was no evidence of hypocholesterolemia at any dietary HC concentration. HC not only retains the ability of AC to enhance fecal excretion of TCDD but also reduces some of the side effects of AC.

Gastrointestinal decontamination

Why has ipecac syrup become less popular in emergency management of poisoning and overdose? When should gastric lavage, activated charcoal, cathartics, or a combination of methods be used? Which patients are candidates for whole-bowel irrigation with polyethylene glycol-electrolyte solution? Drs Harris and Kingston answer these questions and present their recommendations for each of the available management options.

Adsorption of desflurane by the silica gel filters in breathing circuits: an in vitro study

Background

During general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters.

Methods

An HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined.

Results

Significant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001).

Conclusions

The adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia.

Sudden-onset tachypnea and confusion in a previously healthy teenager

Acute intoxication with acetylsalicylic acid is a severe event commonly seen in children resulting from wide availability of this drug without prescription. Cases of self-poisoning resulting from overdose continue to occur and, although far less common, they are often severe and life-threatening. We report a 14-year-old girl who presented to the emergency department with tachypnea and altered mental status as a result of acetylsalicylic acid overdose in a suicide attempt. We discuss her presentation and the pathophysiological considerations leading to the management decisions taken during her emergency department stay, highlighting the role of the clinician and therapeutic drug monitoring consultant. The use of rapid decontamination with multiple doses of charcoal, even when more than 4 hours have passed since ingestion, and the use of urinary alkalinization are stressed. Timely management can obviate the need for dialysis. Published cases of acetylsalicylic acid intoxication are reviewed.

Drugs and pharmaceuticals: management of intoxication and antidotes

The treatment of patients poisoned with drugs and pharmaceuticals can be quite challenging. Diverse exposure circumstances, varied clinical presentations, unique patient-specific factors, and inconsistent diagnostic and therapeutic infrastructure support, coupled with relatively few definitive antidotes, may complicate evaluation and management. The historical approach to poisoned patients (patient arousal, toxin elimination, and toxin identification) has given way to rigorous attention to the fundamental aspects of basic life support--airway management, oxygenation and ventilation, circulatory competence, thermoregulation, and substrate availability. Selected patients may benefit from methods to alter toxin pharmacokinetics to minimize systemic, target organ, or tissue compartment exposure (either by decreasing absorption or increasing elimination). These may include syrup of ipecac, orogastric lavage, activated single- or multi-dose charcoal, whole bowel irrigation, endoscopy and surgery, urinary alkalinization, saline diuresis, or extracorporeal methods (hemodialysis, charcoal hemoperfusion, continuous venovenous hemofiltration, and exchange transfusion). Pharmaceutical adjuncts and antidotes may be useful in toxicant-induced hyperthermias. In the context of analgesic, anti-inflammatory, anticholinergic, anticonvulsant, antihyperglycemic, antimicrobial, antineoplastic, cardiovascular, opioid, or sedative-hypnotic agents overdose, N-acetylcysteine, physostigmine, L-carnitine, dextrose, octreotide, pyridoxine, dexrazoxane, leucovorin, glucarpidase, atropine, calcium, digoxin-specific antibody fragments, glucagon, high-dose insulin euglycemia therapy, lipid emulsion, magnesium, sodium bicarbonate, naloxone, and flumazenil are specifically reviewed. In summary, patients generally benefit from aggressive support of vital functions, careful history and physical examination, specific laboratory analyses, a thoughtful consideration of the risks and benefits of decontamination and enhanced elimination, and the use of specific antidotes where warranted. Data supporting antidotes effectiveness vary considerably. Clinicians are encouraged to utilize consultation with regional poison centers or those with toxicology training to assist with diagnosis, management, and administration of antidotes, particularly in unfamiliar cases.

Activated charcoal is effective but equilibrium dialysis is ineffective in removing oleander leaf extract and oleandrin from human serum: monitoring the effect by measuring apparent digoxin concentration

Accidental poisoning from oleander leaf or oleander tea can be life threatening. The authors studied the effectiveness of activated charcoal and equilibrium dialysis in removing oleander leaf extract and commercially available oleandrin as well as oleandrigenin, the active components of oleander plant, from human serum. Oleander leaf extract was prepared in distilled water and drug-free serum was supplemented with the extract. Then serum was treated with activated charcoal at room temperature and an aliquot was removed at 0 minutes, 10 minutes, 20 minutes, and finally 30 minutes to study the presence of oleander extract by measuring the apparent digoxin concentration using the FPIA for digoxin. The authors observed effective removal of oleander extract by activated charcoal. When the authors supplemented other drug-free serum pools with pure oleandrin or oleandrigenin and then subsequently treated them with activated charcoal, the authors observed complete removal of digoxin-like immunoreactivity at the end of 30 minutes' treatment. When drug-free serum pool supplemented with either oleander leaf extract, oleandrin, or oleandrigenin was passed through a small column packed with activated charcoal, the authors observed almost no apparent digoxin concentration following the passage through the column indicating that activated charcoal is very effective in removing oleander from human serum in vitro. In contrast, when serum pools containing either oleander leaf extract or oleandrin were subjected to equilibrium dialysis against phosphate buffer at pH 7.4, the authors observed no significant reduction in apparent digoxin concentration even after 24 hours. The authors conclude that activated charcoal is effective but equilibrium dialysis is ineffective in removing oleander leaf extract from human serum.

Activated charcoal: the untold story

Introduction. To identify the prevalence and appropriateness of prescribing activated charcoal in the management of acute poisoning and to document patient compliance with treatment.Methods. A prospective study was conducted, between October 1998 and September 1999, on patients attending our accident and emergency department, with a history of overdose. Overdoses were classified as potentially toxic or non-toxic according to the history and/or information received from the National Poisons Information Service.Results. Two hundred and seventy five patients presented following overdose; 17% within one hour, 102 were prescribed charcoal (37.1%) but of these, 40 (39%) refused it, and of the 62 patients (61%) who accepted charcoal only 15 (24.2%) took all that was prescribed. Patients were 5.4 times more likely to take charcoal if they had taken a potentially toxic overdose. Of those who presented within one hour and were judged to have taken a potentially toxic overdose, only three patients took the full-prescribed amount.Conclusion. We report a substantially greater proportion of patients (39%) refusing charcoal than previously reported (9.9%). The widespread availability of TOXBASE Copyright should help redress this discrepancy.

The frequency of complications associated with the use of multiple-dose activated charcoal

STUDY OBJECTIVE

The objective of this study was to determine the frequency of complications associated with the use of multiple-dose activated charcoal.

METHODS

The study population was drawn from 8 tertiary care hospitals in 4 North American cities. Medical records of all inpatients between March 1993 and March 1998 with a discharge diagnosis of poisoning (International Classification of Diseases, 9th edition, Clinical Modification codes 960-989.9) were reviewed to select patients who had received multiple-dose activated charcoal (defined as > or =2 doses administered within 12 hours). Medical records of patients who received multiple-dose activated charcoal were reviewed for patient demographics and clinical information regarding the occurrence of pulmonary aspiration, gastrointestinal obstruction, hypernatremia, hypermagnesemia, corneal abrasion, and other complications associated with the use of multiple-dose activated charcoal.

RESULTS

We reviewed 6,258 medical records, identifying 878 patients who received multiple-dose activated charcoal. We judged 5 (0.6%; 95% confidence interval [CI] 0.1% to 1.1%) patients to have had clinically significant pulmonary aspiration and none (0%; upper 95% CI 0.3%) to have had gastrointestinal obstruction. None of the patients with pulmonary aspiration died or had residual sequelae recorded. Hypernatremia (peak serum sodium >145 mEq/L [145 mmol/L]) was documented in 53 (6.0%; 95% CI 4.4% to 7.6%) patients, of whom 5 (0.6%; 95% CI 0.1% to 1.1%) had a serum sodium concentration of greater than 155 mEq/L (155 mmol/L). Hypermagnesemia (peak serum magnesium >2.5 mg/dL [1.0 mmol/L]) was documented in 27 (3.1%; 95% CI 2.0% to 4.2%) patients, of whom 3 (0.3%; 95% CI 0.1% to 1.0%) had peak values that were greater than 3.75 mg/dL (1.5 mmol/L). One patient had a corneal abrasion (0.1%; 95% CI 0% to 0.6%). No other complications were identified.

CONCLUSION

Clinically significant complications associated with the use of multiple-dose activated charcoal occur infrequently.

Single-dose oral activated charcoal in the treatment of the self-poisoned patient: a prospective, randomized, controlled trial

Oral activated charcoal (OAC) is a universally accepted treatment of the overdose patient. Although the benefits of OAC have been suggested, there are no conclusive clinical data indicating that OAC affects outcome in overdose patients. This study was a prospective, randomized, controlled trial to determine the effects of OAC treatment in the self-poisoned adult patient. Adult patients presenting to the emergency department (ED) with a history of oral overdose were assigned to treatment with OAC (50 g) or supportive care only on an even-odd day protocol. Patients did not undergo gastric evacuation procedures in the ED. The outcome measures were clinical deterioration, length of stay in the ED or hospital, and complication rate. Over a 24-month period, 1479 patients were entered into the study. There were no significant differences in outcome parameters between the OAC treatment group and controls when comparing the length of intubation time, length of hospital stay, and the complication rates associated with the overdose. There was a higher incidence of vomiting and longer length of ED stay associated with OAC treatment. The results of this study indicated that oral drug overdose patients do not require gastric evacuation or charcoal administration. OAC provided no additional benefit to supportive care alone, was associated with a higher incidence of vomiting and a longer length of ED stay, and did not improve clinical outcome.

Charcoal is a sensitive, specific, and stable marker for the diagnosis of aspiration in hamsters

The diagnosis of recurrent aspiration in young children is a perpetual challenge because there is no specific gold standard test to be used. The finding of lipid-laden alveolar macrophages in bronchoalveolar lavage (BAL) is a sensitive but nonspecific marker for the diagnosis of aspiration. We conducted a short-term study comparing tracheal instillation of saline, milk, or a milk-charcoal mixture in hamsters. BAL cytology, lipid-laden alveolar macrophage index, charcoal alveolar macrophage index, and lung histology were monitored for 10 d. A long-term study was performed, and hamsters were monitored for 92 d after milk-charcoal tracheal instillation. Baseline animals (n = 4) had no tracheal instillation. Saline- and milk-instilled animals had BAL performed after 1 (n = 4), 3 (n = 4), and 10 (n = 4) d. Milk-charcoal-instilled animals had BAL performed after 1 (n = 4), 3 (n = 4), 10 (n = 4), 30 (n = 2), 58 (n = 2), and 92 (n = 2) d after tracheal instillation. Total cell counts and percent neutrophils in BAL fluid increased significantly and similarly after milk and milk-charcoal instillation on d 1 compared with baseline and saline-instilled animals. Lipid-laden alveolar macrophage index increased significantly only on d 3 after milk and milk-charcoal instillation compared with all days in the saline-instillation group. Charcoal alveolar macrophage index increased significantly after milk-charcoal instillation (d 1-58) from baseline or all days in the saline-instillation group. We conclude that charcoal particles instilled in tracheas of hamsters can be easily identified in BAL fluid and in lung parenchyma for as long as 3 mo after a single instillation and could potentially be used as a sensitive, specific, and stable marker for the diagnosis of aspiration, although the issue of its applicability to humans is still unsolved.

Digoxin toxicity in chronic renal failure: treatment by multiple dose activated charcoal intestinal dialysis

1. Digoxin toxicity can result from overdose or iatrogenic causes, especially if renal function is impaired. 2. We present a case of digoxin toxicity presenting with severe bradycardia and hypotension in a 66 year old man with chronic renal failure. Regular haemodialysis had, as predicted, failed to reduce his plasma digoxin concentration. Digoxin specific antibody fragments (Fab) were not readily available and their use was probably inappropriate as they are normally renally eliminated. 3. The patient was successfully treated by two prolonged courses of intestinal dialysis with repeated doses of activated charcoal over 48 and 72 h and totaling 400 g and 600 g, respectively. However, the patient found the activated charcoal extremely unpalatable. 4. Multiple dose activated charcoal intestinal dialysis (MDACID) has been recently advocated for use in a wide range of poisonings. The technique takes advantage of the large surface area of the small intestine to eliminate drugs and metabolites, over several days if necessary. The pharmacokinetics of digoxin toxicity in chronic renal failure make intestinal dialysis an appropriate method of treatment but the realisation of the true potential of this technique awaits a more palatable absorbent or formulation.

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.

Experience with 732 acute overdose patients admitted to an intensive care unit over six years

OBJECTIVE

To determine the outcome in patients with acute overdose requiring admission to the Intensive Care Unit (ICU).

DESIGN

Prospective survey of all overdose admissions to an ICU over a six-year period ending January 1991.

SETTING

Tertiary referral adult teaching hospital.

PATIENTS

732 consecutive patients with acute overdose.

OUTCOME MEASURES

Death rate, use and duration of mechanical ventilation, type of compound taken and compounds associated with a fatal outcome.

RESULTS

The 732 patients represented 13.8% of all admissions and 6% of the available ICU bed-days. Comparison with all admissions to the Emergency Department for acute overdose over a 27-month period ending April 1990 indicated that 22% of these patients were admitted to the ICU. Among the patients admitted to the ICU, tricyclic antidepressants, benzodiazepines and alcohol were the most frequently used compounds. More than one compound had been taken by 46.8% of the patients. Mechanical ventilation was required in 79.5% of the patients and 14 (2%) died.

CONCLUSIONS

Acute overdose is a common cause of admission to the ICU but has a mortality rate of only 2%. In contrast to the overdoses taken by survivors, patients taking fatal overdoses are more likely to have taken a large dose of a single drug, or a non-medicinal compound.

Update in medical toxicology

This article examines some current issues in toxicologic care. First there is a review of the scope of pediatric poisonings and some aspects of initial management. Then there is a discussion of the decision-making process required to properly use gastric decontamination in the management of poisonings. Each of the common methods available--emesis, gastric lavage, activated charcoal, catharsis, and whole bowel irrigation--is discussed. Finally, several new and old antidotes are reviewed, namely naloxone, glucagon, bicarbonate, dimercaptosuccinic acid, digoxin-specific fab fragments, and flumazenil.

Acute toxic reaction to carbamazepine: clinical effects and serum concentrations

The clinical spectrum of toxic effects and serum concentrations after ingestion of carbamazepine were studied in 82 pediatric patients. Serum carbamazepine level was related to the depth of coma (p less than 0.001), convulsions (p = 0.002), hypotension (p less than 0.001), and the requirement for mechanical ventilation (p less than 0.001). In 10 patients in deep coma with a Glasgow Coma Scale (GCS) of 3-4, the mean serum level was 213 mumol/L (range 143 to 343); seizures, ventilatory failure, or hypotension caused by myocardial failure and conduction defects were observed. In four of these, large doses of inotropic agents were required, one patient was treated with plasmapheresis, and two died--one of cardiac failure and one of aspiration pneumonitis. In 27 patients with moderate coma (GCS 5-8), the mean serum level of carbamazepine was 112 mumol/L (range 63 to 176); convulsions were observed in two patients in this group. In 45 patients whose conscious state was mildly depressed or normal (GCS 9-15), the mean serum level was 73 mumol/L (range 37 to 128); additional effects were drowsiness (80%), ataxia (53%), nystagmus (38%), vomiting (17%), and dystonia (7%). I conclude that patients with serum carbamazepine levels of approximately 100 mumol/L require close observation, whereas those with levels greater than 150 mumol/L may require intensive life support.

Physicochemical characteristics of drugs and response to repeat-dose activated charcoal

Although the administration of repeated doses of activated charcoal has been advocated to increase the systemic clearance of many drugs, it is unknown whether a drug's physicochemical properties are associated with enhanced removal by repeat-dose activated charcoal. The English language literature was searched to identify clinical studies evaluating repeat-dose activated charcoal. Percent reduction in plasma elimination half-life during repeat-dose activated charcoal was calculated and correlated with the drugs' characteristics. A step-wise multiple regression analysis with the independent variables of the drugs' molecular weight, pKa, plasma protein-binding, intrinsic plasma elimination half-life, and volume of distribution failed to identify potential predictors (P = .1) of effectiveness of repeat-dose activated charcoal. This analysis suggested that charcoal therapy was more effective for drugs with a longer intrinsic half-life (r2 = .24, P = .04). A uniform framework that evaluates the physicochemical characteristics of drugs and their response to repeat-dose activated charcoal is needed to better define which patients would benefit from repeat-dose activated charcoal therapy.

Drug overdose — reducing the load

OBJECTIVE

To review available information about various methods for reducing gastrointestinal absorption of a poison or drug.

DATA SOURCES

Articles on overdose and accidental poisoning generated by the Australian Medlars Service and concentrating on the period between 1985 and 1990 were surveyed. Earlier studies were included if relevant.

STUDY SELECTION AND DATA EXTRACTION

English language articles with an emphasis on studies using objective methods to measure individual and comparative efficacy of gastrointestinal decontamination techniques were selected. A total of 65 articles were reviewed.

DATA SYNTHESIS

Gastric emptying procedures (gastric lavage or emesis caused by syrup of ipecac) are only effective if performed within one hour of drug ingestion. Gastric lavage is superior to syrup of ipecac. Oral administration of activated charcoal is more effective than either gastric emptying procedure, and is recommended for most cases of poisoning. Cathartics (sorbitol) can be used with activated charcoal. Whole bowel lavage with polyethylene glycol is indicated in selected cases of potentially lethal overdose where the toxic substance cannot be absorbed by charcoal and has passed the pylorus.

CONCLUSIONS

Children--syrup of ipecac can be given at home to children older than 12 months. Most children who reach hospital can be treated by charcoal alone. ADULTS--Most patients are managed with supportive care and, in the absence of contraindications, a single dose of activated charcoal if seen within four hours of ingestion of the poison or drug. Gastric lavage is used if the patient presents within one hour of ingestion and has clinical features of toxicity.

Management of theophylline overdose patients in the intensive care unit

In a retrospective survey of all adults admitted to the Intensive Care Unit with acute theophylline poisoning over the last five years, we identified 38 patients (6.8% of all admissions for poisoning), two of whom died. Thirty-five (92%) had taken a sustained-release preparation. Eight patients had grand mal seizures and six developed arrhythmias (ventricular fibrillation, 3; atrial fibrillation, 2; supraventricular tachycardia, 1). Severe vomiting was present in 34 (89%) and proved to be a serious obstacle to the administration of enteral charcoal. The vomiting was controlled by intravenous metoclopramide in seventeen patients (50%), but the remaining seventeen required mechanical ventilation with sedation and muscle relaxation for the effective delivery of nasogastric charcoal. Importantly, in nine (24%), the serum theophylline concentration continued to rise despite enteral charcoal. Charcoal haemoperfusion was used in seven (18%). We present an algorithm for the management of severe, acute theophylline poisoning.