Gastric decontamination performed 5 min after the ingestion of temazepam, verapamil and moclobemide: charcoal is superior to lavage

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.

Novel method to estimate the appropriate dosing interval for activated charcoal to avoid interaction with other drugs

PURPOSE

Activated charcoal is known to adsorb a variety of drugs concomitantly administered and reduce their intestinal absorption, and separating the dosing is considered a practical approach to avoid this drug interaction. The aim of the present study was to develop and validate a simple method to estimate the sufficient dosing interval to avoid drug interaction using the pharmacokinetic profile of the subject drugs administered alone and the amplitude of interaction upon simultaneous administration with activated charcoal.

METHODS

For each subject drug, the pharmacokinetic profile and the amplitude of interaction, as assessed by AUCR (the ratio of area under the plasma concentration-time curve (AUC) in the presence of activated charcoal to that in its absence), were collected from previous reports. The AUCR value was estimated based on the compartment model under the assumption that the subject drug in the first gastrointestinal compartment is immediately adsorbed to a certain extent upon the administration of activated charcoal. The estimated AUCR (AUCR_e) for each drug with certain dosing interval was compared with the respective AUCR value reported previously (AUCR_obs).

RESULTS

Among twenty concentration profiles for 14 subject drugs obtained from previous reports, 15 AUCR_e values fell in the range of 80-120% of the respective AUCR_obs values.

CONCLUSION

The developed method enabled estimation of the amplitude of DDI by activated charcoal administered in a certain dosing interval, whereas overestimation of AUCR_e was observed for drugs that undergo extensive enterohepatic circulation.

Management of Calcium Channel Blocker Toxicity in the Pediatric Patient

Calcium channel blockers (CCBs) are commonly prescribed cardiovascular medications used in several disease states including hypertension, coronary artery disease, and atrial fibrillation. Inadvertent exposure or intentional overdose of CCBs may result in hypotension, bradycardia, dysrhythmias, conduction disturbances, and hyperglycemia. In the most severe cases, CCB toxicity can lead to rapid cardiovascular collapse. Given the risk of significant morbidity and mortality associated with CCB toxicity, it is important that health care professionals are able to recognize and treat patients who present with a potentially toxic ingestion. Due to the paucity of literature in managing pediatric patients with severe CCB toxicity, treatment strategies for pediatric patients are mostly limited to case reports and extrapolation from expert consensus recommendations for adults. All pediatric patients with a potentially toxic CCB ingestion should be evaluated in the emergency department. Activated charcoal may be considered for asymptomatic patients presenting within an hour of ingestion. Symptomatic patients should be placed under cardiac monitoring and treatments to stabilize the patient's hemodynamics should not be delayed. Traditional first-line IV therapies include small boluses of fluids, calcium, and vasopressors. High-dose insulin has been proposed to independently increase inotropy and improve CCB-induced hypoinsulinemia and insulin resistance that results from CCB inhibition of insulin release from pancreatic β-islet cells. High-dose insulin is recommended as first-line therapy for adults and shows promising efficacy and safety in several pediatric case reports. Intravenous lipid emulsion may be considered in patients who are refractory to first-line therapies, although the data for pediatric patients are extremely limited.

Pharmacological and mechanical management of calcium channel blocker toxicity

Cardiovascular instability associated with calcium channel blocker toxicity comprises a small percentage of overdose presentations, yet they are associated with a high mortality rate. We detail the management of a 64-year-old man who took an intentional overdose of 840 mg nimodipine. We include the treatment he received and highlight the scarcity of evidence behind the use of gastric decontamination, calcium, glucagon, intravenous lipid emulsion, high-dose insulin therapy, sodium bicarbonate, vasopressors and methylene blue in calcium channel blocker toxicity. Additionally, the article explores the use of electrical pacing and venoarterial extracorporeal membrane oxygenation (VA-ECMO). Following successful weaning of VA-ECMO, the patient was successfully extubated but remained neurologically impaired due to hypoxic-ischaemic brain injury, critical care polyneuropathy and renal failure requiring dialysis. He has cerebral performance category 3; he has mild cognitive impairment but able to perform some activities of daily living independently and communicate his thoughts and needs. He requires no respiratory or cardiovascular support.

Experts Consensus Recommendations for the Management of Calcium Channel Blocker Poisoning in Adults

OBJECTIVE

To provide a management approach for adults with calcium channel blocker poisoning.

DATA SOURCES, STUDY SELECTION, AND DATA EXTRACTION

Following the Appraisal of Guidelines for Research & Evaluation II instrument, initial voting statements were constructed based on summaries outlining the evidence, risks, and benefits.

DATA SYNTHESIS

We recommend 1) for asymptomatic patients, observation and consideration of decontamination following a potentially toxic calcium channel blocker ingestion (1D); 2) as first-line therapies (prioritized based on desired effect), IV calcium (1D), high-dose insulin therapy (1D-2D), and norepinephrine and/or epinephrine (1D). We also suggest dobutamine or epinephrine in the presence of cardiogenic shock (2D) and atropine in the presence of symptomatic bradycardia or conduction disturbance (2D); 3) in patients refractory to the first-line treatments, we suggest incremental doses of high-dose insulin therapy if myocardial dysfunction is present (2D), IV lipid-emulsion therapy (2D), and using a pacemaker in the presence of unstable bradycardia or high-grade arteriovenous block without significant alteration in cardiac inotropism (2D); 4) in patients with refractory shock or who are periarrest, we recommend incremental doses of high-dose insulin (1D) and IV lipid-emulsion therapy (1D) if not already tried. We suggest venoarterial extracorporeal membrane oxygenation, if available, when refractory shock has a significant cardiogenic component (2D), and using pacemaker in the presence of unstable bradycardia or high-grade arteriovenous block in the absence of myocardial dysfunction (2D) if not already tried; 5) in patients with cardiac arrest, we recommend IV calcium in addition to the standard advanced cardiac life-support (1D), lipid-emulsion therapy (1D), and we suggest venoarterial extracorporeal membrane oxygenation if available (2D).

CONCLUSION

We offer recommendations for the stepwise management of calcium channel blocker toxicity. For all interventions, the level of evidence was very low.

Activated charcoal for acute overdose: a reappraisal

Sometimes mistakenly characterized as a 'universal antidote,' activated charcoal (AC) is the most frequently employed method of gastrointestinal decontamination in the developed world. Typically administered as a single dose (SDAC), its tremendous surface area permits the binding of many drugs and toxins in the gastrointestinal lumen, reducing their systemic absorption. Like other decontamination procedures, the utility of SDAC attenuates with time, and, although generally safe, it is not free of risk. A large body of evidence demonstrates that SDAC can reduce the absorption of drugs and xenobiotics but most such studies involve volunteers and have little generalizability to clinical practice. Few rigorous clinical trials of SDAC have been conducted, and none validate or refute its utility in those patients who are intuitively most likely to benefit. Over the past decade, a growing body of observational data have demonstrated that SDAC can elicit substantial reductions in drug absorption in acutely poisoned patients. The challenge for clinicians rests in differentiating those patients most likely to benefit from SDAC from those in whom meaningful improvement is doubtful. This is often a difficult determination not well suited to an algorithmic approach. The present narrative review summarizes the data supporting the benefits and harms of SDAC, and offers pragmatic suggestions for clinical practice.

Does prearrival communication from a poison center to an emergency department decrease time to activated charcoal for pediatric poisoning?

OBJECTIVE

A poison center plays an important role in directing appropriate care, which is critical in reducing morbidity due to poisoning. Activated charcoal (AC) is one intervention for some poisonings. This study examined whether children with a poisoning who were preannounced by a poison center received AC earlier than patients without a referral.

METHODS

A retrospective review of AC administration in children aged 0 to 18 years in a pediatric emergency department (ED) from 2000 to 2006 was performed. Abstracted covariates were poison center referral status, age, sex, acuity, disposition, transportation mode, triage time, and time of AC administration. Analysis of variance controlling for covariates tested the equality of mean time intervals between the groups with and without a poison center referral.

RESULTS

Three hundred fifty-one cases met the inclusion criteria. One hundred thirty-five (39%) were male. Eighty cases (23%) had a poison center referral. Time from triage to charcoal administration for patients with a poison center referral was a mean of 59 (SD, 34) minutes. Time for the group without a referral was a mean of 71 (SD, 43) minutes (P = 0.0036).

CONCLUSIONS

Advanced communication from a poison center was associated with earlier administration of AC in the ED for this population. Nevertheless, the duration to charcoal administration was frequently suboptimal. Triage and prehospital practices should be reexamined to improve timeliness of AC when indicated and consider exclusion of administration if beyond an appropriate time frame. Advanced notification should be the paradigm for all poison centers, and early response protocols for poison center referrals should be used by EDs.

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.

Position paper: gastric lavage

Gastric lavage should not be employed routinely, if ever, in the management of poisoned patients. In experimental studies, the amount of marker removed by gastric lavage was highly variable and diminished with time. The results of clinical outcome studies in overdose patients are weighed heavily on the side of showing a lack of beneficial effect. Serious risks of the procedure include hypoxia, dysrhythmias, laryngospasm, perforation of the GI tract or pharynx, fluid and electrolyte abnormalities, and aspiration pneumonitis. Contraindications include loss of protective airway reflexes (unless the patient is first intubated tracheally), ingestion of a strong acid or alkali, ingestion of a hydrocarbon with a high aspiration potential, or risk of GI hemorrhage due to an underlying medical or surgical condition. A review of the 1997 Gastric Lavage Position Statement revealed no new evidence that would require a revision of the conclusions of the Statement.

Eficacia y seguridad de la descontaminación digestiva en la intoxicación medicamentosa aguda

BACKGROUND AND OBJECTIVE

Gut decontamination (GD) may be used as a treatment for acute therapeutic drug overdose (ATDO) to reduce the absorption of the drug and thereby avoid the presence or worsening of signs and symptoms of intoxication. The objective of this study was to assess the efficacy and safety of GD in ATDO patients.

PATIENTS AND METHOD

A 4-month prospective observational study was designed to include all patients admitted to the emergency department due to an ATDO. On admission, epidemiological data, vital signs and physical examination results were all recorded and a blood sample was taken for toxicological analysis. An algorithm was used to determine the GD method to be applied. A clinical reassessment was made at 3-6 hours and a further sample was taken for toxicological analysis. Patients were followed until hospital discharge, with all possible adverse events due to GD being recorded.

RESULTS

Ninety-four patients were included. GD was indicated in 60 patients (63.8%): 3.3% received ipecacuana syrup, 8.3% gastric lavage, 21.6% gastric lavage followed by activated charcoal and 71.6% oral activated charcoal alone. The clinical state worsened in 19.1% of patients, usually on the basis of a diminished consciousness. Adverse events attributable to GD were observed in 8.3% of patients. A toxicological analysis was made in 50 patients and in 42% of them, drug concentrations were higher at 3 or 6 hours than on admission. An analysis of the method of decontamination used showed that the procedure recommended by the algorithm was applied in 70 patients (group A) while in the remaining 24 (group B) another decontamination technique was used. Clinical deterioration was seen in 14.3% of patients in group A and 33.3% in group B (p = 0.041). There was a favourable evolution of the analytic curve in 63.9% patients in group A and 42.9% in group B (p = NS); severe adverse events attributable to GD were suffered by 2.4% patients in group A and 11.1% in group B (p = NS).

CONCLUSIONS

The efficacy and safety of GD in ATDO increases in patients in whom the decision-making algorithm is applied. However, this does not prevent clinical deterioration or continued drug absorption in all cases and may be accompanied by adverse events.