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

An in vitro study of metformin adsorption to activated charcoal

INTRODUCTION

Metformin is a biguanide used to manage patients with type 2 diabetes mellitus. However, metabolic acidosis with an elevated lactate concentration and death caused by metformin overdoses are toxicological concerns. Although activated charcoal has been widely used for gastrointestinal decontamination in cases of acute poisoning, there is no evidence regarding its efficacy in treating metformin overdoses. We therefore evaluated the adsorptive capacity of activated charcoal for metformin in vitro.

METHODS

Activated charcoal (specific surface area: 1,080 m2/g) mixed with various concentrations of metformin solution was dissolved in simulated gastric and intestinal fluids at 37° Celsius. The suspension was then filtered and the metformin concentration in the filtrate was determined using high-performance liquid chromatography. The maximum adsorptive capacity for metformin was calculated using the Langmuir adsorption isotherm equation.

RESULTS

The amount of metformin adsorbed per gram of activated charcoal ranged from 0.7 to 8.1 mg/g at pH 1.2, and from 8.4 to 48.2 mg/g at pH 6.8. The corresponding maximum adsorptive capacities were 10.6 mg/g and 55.9 mg/g respectively.

DISCUSSION

The maximum adsorptive capacity of activated charcoal for metformin was similar to that of its capacity for other poorly adsorbed substances. This is likely because metformin is water-soluble and has high polarity-factors that correlate with poor adsorption on activated charcoal.

CONCLUSIONS

The maximum adsorption of metformin by activated charcoal was low. Therefore, activated charcoal may not be effective for treating patients with metformin overdose.

Predicting mortality in paraquat poisoning through clinical findings, with a focus on pulmonary and cardiovascular system disorders

BACKGROUND

Paraquat, one of the most widely used herbicides, poses a significant risk of mortality through self-poisoning and subsequent multiple organ failure. The primary objective aimed to identify the factors associated with death in patients poisoned by paraquat.

METHODS

A cross-sectional retrospective review was conducted at a tertiary referral hospital over five years. Eligible patients presented with acute paraquat toxicity between 1 January 2016 and 31 December 2020. Medical records of 148 patients were reviewed.

RESULTS

The in-hospital fatality rate was found to be 21.8%. Multivariate analysis revealed that the amount of paraquat ingested and clinical presentations, particularly pulmonary and cardiovascular system disorders, were significantly associated with mortality.

CONCLUSION

Our study highlights that the amount of paraquat ingested, along with the presence of pulmonary and cardiovascular system disorders, can serve as prognostic indicators for mortality rates in cases of paraquat poisoning. These findings have important implications for physicians in predicting the prognosis and mortality of paraquat poisoning patients.

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..

Recent developments in the use of activated charcoal in medicine

One of the raw forms of graphite is activated charcoal which has an extensive surface area allowing for the adsorption of a wide range of chemicals. It possesses the strongest physical adsorption forces of the available materials, as well as the largest volume of adsorbing porosity. Activated charcoal acts as an adsorbent, collecting and storing substances in the gastrointestinal tract, reducing or blocking absorption in the bloodstream. The ingested toxins interact with charcoal by recycling toxins in the intestinal cavity. In cases where the drug has not been absorbed from the abdominal system, it is recirculated through the liver and intestines or by means of passive diffusion or active secretion. The article aims to review the most recent advances in the use of the activated charcoal, including the dose, how charcoal acts in the body, the mechanism of action, administration, contraindications, as well as the impact of various factors on the adsorption process. In addition, we also discussed numerous medical applications of activated charcoal.

Refractory Torsades de Pointes Due to Dofetilide Overdose

Dofetilide, a class III antiarrhythmic, is widely used in the treatment of cardiac arrhythmias. Antiarrhythmic drugs can have a long duration of action that prolongs the QT interval. This causes bradycardia that predisposes to R-on-T phenomenon subsequently leading to torsades de pointes (TdP). This necessitates constant monitoring to prevent or treat ventricular arrhythmias or bradycardia associated with cardiac medications. Although extremely rare, dofetilide overdose has been described in the literature. However, no evidence found in the current literature required prolonged intervention after the initial acute stabilization, leading to scarcity of data for treatment of ongoing dofetilide overdose. We present the case of an intentional dofetilide overdose in a 61-year-old Caucasian woman with a history of congestive heart failure, atrial fibrillation, stage IIIb chronic kidney disease, diabetes mellitus type II, hypothyroidism, morbid obesity, and hypertension that required extensive interventions for refractory TdP that lasted 4 days. Therapeutic as well as excess dosage of dofetilide can lead to TdP, which is usually controlled by decreasing the dose or terminating drug administration. If the arrhythmia is not resolved, guidelines recommend management with activated charcoal if ingestion is within 15 minutes, followed by administration of 2 g IV (intravenous) magnesium and addressing the electrolyte imbalance. However, if the arrhythmia is persistent due to ongoing dofetilide toxicity, isoproterenol is given as a bridge to overdrive pacing and dopamine is used as an alternative to isoproterenol.

Prevalence of medically unsupervised activated charcoal use a cause for concern in celiac disease?

BACKGROUND

Celiac disease is an autoimmune disorder that causes an intolerance to gluten. Owing to hidden sources, lack of clear labeling, and cross-contamination, it is not uncommon for individuals with celiac disease to inadvertently ingest gluten. A strict gluten-free diet is the only treatment.

OBJECTIVES

The purpose of this study was to identify the frequency of activated charcoal use in celiac disease as a purported remedy despite the lack of literature on the safety and efficacy of the practice and to elucidate the manner in which using activated charcoal as a treatment for acute gluten ingestion is being communicated.

METHODS

Using a descriptive study design, a Web-based survey was sent to members of the celiac disease community via social media pages for voluntary participants 18 years and older diagnosed with celiac disease. Participants were stratified into 3 major groups: (1) those who had heard of using activated charcoal as a remedy to counteract gluten ingestion and used it, (2) those who had heard of using activated charcoal but had not used it, and (3) those who had not heard of using activated charcoal.

RESULTS

In subjects with celiac disease, 424 of 1613 respondents (26%) had heard of using activated charcoal as a potential remedy for gluten ingestion, and 12% had used it. The top source of information regarding any general information including remedies for maladies related to celiac disease was social media networks 72.3% (879/1613). Of those who had used activated charcoal, 122 participants (61.3%) reported subjectively feeling a reduced severity of symptoms.

CONCLUSION

Pharmacists should be aware of the off-label use of activated charcoal for accidental gluten ingestion in celiac disease. Pharmacists should educate patients with celiac disease that there is not sufficient evidence to support the use of 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.

[Actions that should not be taken with a paediatric patient who has been exposed to a potentially toxic substance]

OBJECTIVE

To show the preparation process by the Poisoning Working Group of the Spanish Society of Paediatric Emergencies (GTI-SEUP), of the list of things «not to do» for a paediatric patient who has been exposed to a potentially toxic substance.

METHOD

The preparation process of the list was carried out in three phases. First: «Brainstorming» that was open to all members of the GTI-SEUP. Second: Recommendations were selected by following modified-Delphi methodology. All participants were asked to rate the proposals (from 1 = strongly disagree to 9 = strongly agree). Those with an average score greater than 8 were accepted (provided that at least two-thirds of the participants had given them a score ≥ 7), and a second consultation was made for the recommendations with an average score between 6 and 8. Third: Writing and creating a consensus of the final document was done.

RESULT

A total of 11 proposals were initially obtained. Thirty-two of the 57 GTI-SEUP participants completed the scoring questionnaire. In the first consultation, seven «not to do» recommendations were accepted, and four obtained a doubtful average score (between 6 and 8). After the second consultation, the list was made up of eight recommendations. Two refer to general management, four to gastrointestinal decontamination techniques, and two to the administration of antidotes.

CONCLUSION

The list of actions that should not be taken with a child that has been exposed to a possible poison is a consensus tool, within the GTI-SEUP, to promote improvement in the quality of care offered to these patients. This improvement is based on avoiding unnecessary measures, which can sometimes be harmful to the child.

The Use of Activated Charcoal to Treat Intoxications

BACKGROUND

In 2016, according to the German Federal Statistical Office, 178 425 cases of intoxication (poisoning) were treated in German hospitals. The poison control centers in the German-speaking countries gave advice in a total of 268 787 instances of poisoning in that year, and use of activated charcoal was recommended in 4.37% of cases. The application of activated charcoal plays a major role in both primary and secondary detoxification. This article serves as an overview of the mechanism of action, indications, contraindications, modes of application, and dosing of activated charcoal.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed. The opinions of experts from the poison control centers in the German-speaking countries were considered in the interpretation of the data.

RESULTS

The administration of activated charcoal is indicated to treat moderately severe to life-threatening intoxication. It should be carried out as soon as possible, within the first hour of the ingestion; timed-release preparations can be given up to 6 hours after the ingestion. An important contraindication is impaired consciousness with the danger of aspiration in a patient whose air- way has not yet been secured. Activated charcoal is ineffective or inadequately effective in cases of poisoning with acids or bases, alcohols, organic solvents, inorganic salts, or metals. The proper dosage consists of an amount that is 10 to 40 times as much as that of the intoxicating substance, or else 0.5-1 g/kg body weight in children or 50 g in adults. Repeated application is indicated for intoxications with agents that persist for a longer time in the stomach and for intoxications with timed-release drugs or drugs with a marked enterohepatic or entero-enteric circulation. The routine combination of activated charcoal with a laxative is not recommended.

CONCLUSION

Even though intoxications are common, there is still no internationally valid guideline concerning the administration of activated charcoal. A precise analysis of the risks and benefits is needed for each administration, and a poison control center should be consulted for this purpose.

Effect of Biliary Drainage on the Toxicity and Toxicokinetics of Amanita exitialis in Beagles

Amatoxin poisoning induces delayed-onset acute liver failure, which are responsible for more than 90% of deaths in mushroom poisoning. It has been postulated from animal and human studies that biliary drainage interrupting enterohepatic amatoxin circulation may affect amatoxin poisoning. Dogs were randomly divided into four groups of six animals each. In 20 mg/kg and 60 mg/kg with biliary drainage groups, after accepting bile drainage operation, beagles were fed Amanita exitialis powder (20 or 60 mg/kg) in starch capsules. In control and bile drainage groups, the beagle dogs were fed with empty capsules. They were assessed for toxicity signs, biochemical and pathological changes, and peptide toxins in plasma, urine and bile. The data were directly compared with those from our published studies on Amanita exitialis-exposed beagles without biliary drainage. Amatoxins were rapidly absorbed and eliminated from plasma after Amanita exitialis ingestion. Amatoxins in 0–1-day urine accounted for more than 90% of the total urine excretion, and amatoxins in bile accounted for less than 20% of the total urine and bile excretion. The dogs with biliary drainage showed less severe toxicity signs and biochemical and pathological changes and much lower internal exposure than dogs without biliary drainage. Biliary drainage caused a more than 70% reduction in intestinal amatoxin absorption and could reduce amatoxin absorption from the gastrointestinal tract.

Lethal Tricyclic Antidepressant Overdose

Tricyclic antidepressant remains widely prescribed despite its dangerous cardiovascular and neurological effects in overdosed patients. We present a case of lethal dothiepin overdose and discuss the major complications and its management strategies.

International Variability in Gastrointestinal Decontamination With Acute Poisonings

BACKGROUND AND OBJECTIVES

Identifying international differences in the management of acute pediatric poisonings may help improve the quality of care. The objective of this study was to assess the international variation and appropriateness of gastrointestinal decontamination (GID) procedures performed in children and adolescents who present with acute poisonings to emergency departments.

METHODS

This was an international, multicenter, cross-sectional prospective study including children <18 years with poisoning exposures presenting to 105 emergency departments in 20 countries from 8 global regions belonging to the Pediatric Emergency Research Networks. Data collection started between January and September 2013 and continued for 1 year. The appropriateness of GID procedures performed was analyzed using the American Academy of Clinical Toxicology and the European Association of Poisons Centres and Clinical Toxicologists' recommendations. Multivariate logistic regression was performed to identify independent risk factors for performing GID procedures.

RESULTS

We included 1688 patients, 338 of whom (20.0%, 95% confidence interval 18.1%-22.0%) underwent the following GID procedures: activated charcoal (166, 49.1%), activated charcoal and gastric lavage (122, 36.1%), gastric lavage (47, 13.9%), and ipecac (3, 0.9%). In 155 (45.8%, 40.5%-51.2%), the GID procedure was considered appropriate, with significant differences between regions. Independent risk factors for GID procedures included age, toxin category, mechanism of poisoning, absence of symptoms, and the region where the intoxication occurred (P < .001).

CONCLUSIONS

Globally, there are substantial differences in the use and appropriateness of GID procedures in the management of pediatric poisonings. International best practices need to be better implemented.

In Vitro Study of Adsorption Kinetics of Dextromethorphan Syrup onto Activated Charcoal in Simulated Gastric and Intestinal Fluids

Adsorption kinetics of dextromethorphan (DXM) syrup in simulated gastric and intestinal fluids onto activated charcoal (AC) were investigated in an in vitro model. The adsorption studies were performed as a function of time, initial concentration, and temperature. The quantification of DXM adsorbed onto AC was obtained from the Langmuir adsorption isotherms using HPLC. The maximum adsorption capacities (at 95% confidence limits) of AC for DXM were 111.615 [106.38; 126.85] mg in simulated intestinal environment (pH 6.8) and 78.314 [86.206; 70.422] mg in simulated gastric environment (pH 1.2). The adsorption capacity of AC for DXM in simulated gastric fluid (pH 1.2) was not significantly different from the adoption capacity of AC for DXM in simulated intestinal fluid (pH 6.8). Moreover, the adsorption kinetics behavior of dextromethorphan onto AC followed pseudo-second-order kinetics. Our results show that AC in therapeutically acceptable doses can be beneficial in the majority of oral overdose of DXM.

Use and knowledge of single dose activated charcoal: A survey of Australian doctors

OBJECTIVE

The use of single dose activated charcoal (SDAC) as a means of gastric decontamination is declining. The present study examined the potential use of SDAC in common overdose scenarios by Australian emergency doctors, compared with clinical toxicologists and current guidelines.

METHODS

We conducted a cross-sectional survey of emergency doctors and toxicologists on the use of SDAC. The survey covered demographic data, education and previous use of SDAC and six clinical scenarios. The scenarios selected included agents not bound to SDAC, sustained-release preparations and ingestions at varying time points. Statistical calculations were performed using Fisher's exact test.

RESULTS

There were 397 emergency doctors and 20 toxicologists who responded to the survey. Seventy-one per cent (n = 280/397) of emergency doctors indicated they had received some education on decontamination. Eighty-three per cent (n = 331/397) had administered SDAC during their medical career, 29% (n = 117/397) within the past year. There was a significant difference in responses between emergency doctors and toxicologists in two scenarios; a toxic paracetamol ingestion presenting within 1 h (P = 0.009) and verapamil ingestion in a 3 year old boy (P = 0.001). Toxicologists were more likely to administer SDAC in these scenarios, 89% (n = 16/18) and 88% (n = 15/17), respectively, compared with 52% (n = 197/381) and 43% (n = 158/371) of emergency doctors.

CONCLUSIONS

Our study showed that there is a significant variation in the use of SDAC between toxicologists and emergency doctors in some scenarios. Clinical toxicologists are more likely to administer SDAC in certain overdose settings. It is essential to provide education on the benefits versus actual risks of SDAC in acute poisoning so that doctors will understand when to administer SDAC or seek further advice.

Adult glyburide ingestions reported to Texas poison control centers, 1998—2005

Limited information exists on potentially adverse adult glyburide ingestions reported to poison control centers. Using adult glyburide ingestions reported to Texas poison control centers during 1998—2005, the proportion of cases involving serious outcomes was determined for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI). Of 126 cases identified, 49 (39%) involved serious outcomes. Serious outcomes were significantly more likely to occur with a maximum dose > 24 mg (RR 4.74, 95% CI 1.74—14.90) or >4 tablets (RR 3.27, CI 1.57—7.31), where the circumstances of the exposures involved self-harm or malicious intent (RR 2.44, CI 1.33—4.46), or the patient was already at or en route to a health care facility when the poison control center was contacted (RR 12.89, CI 4.00—66.12) or referred to a health care facility by the poison control center (RR 12.21, CI 3.53—65.01). The severity of the outcome associated with adult glyburide ingestions depended on the dose and the circumstances of the ingestion. The management of patients with severe outcomes was more likely to involve health care facilities. Such information is useful for creating triage guidelines for the management of adult glyburide ingestions. Human & Experimental Toxicology (2007) 26: 563—571.

Current Controversies in Gastrointestinal Decontamination

Most poisonings reported to American poison control centers occur in the home. The most common route of exposure is ingestion, which is responsible for most fatalities. The goal of gastrointestinal decontamination is to prevent absorption of the toxin. Trends in treating poisoned patients have changed over the past few decades in light of a move toward practicing evidence-based medicine. Efficacy and clinical outcome have come into question and have led to position papers published recently regarding syrup of ipecac, gastric lavage, activated charcoal, and whole-bowel irrigation. These different methods of decontamination and the scientific data supporting each one will be reviewed, and the current controversies surrounding each will be discussed.

A study on the cytotoxicity of carbon-based materials

With an aim to understand the origin and key contributing factors towards carbon-induced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, X-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROS) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicity in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under this study. None of the carbons induced oxidative stress to the cells as indicated by the ROS generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell.

Management of exogenous intoxication by carbamates and organophosphates at an emergency unit

Summary Objectives: to evaluate and indicate the procedure to be followed in the health unit, both for diagnosis and the treatment of acute exogenous intoxications by carbamates or organophosphates. Methods: a descriptive study based on retrospective analysis of the clinical history of patients diagnosed with intoxication by carbamates or organophosphates admitted at the emergency unit of the Hospital de Urgências de Sergipe Governador João Alves (HUSE) between January and December of 2012. Some criteria were evaluated, such as: intoxicating agent; patient's age and gender; place of event, cause, circumstances and severity of the intoxication; as well as signs and symptoms of the muscarinic, nicotinic and neurological effects. Results: seventy patients (average age: 25±19.97) formed the study's population. It was observed that 77.14% of them suffered carbamate intoxication. However, organophosphate intoxications were more severe, with 68.75% of patients presenting moderate to severe forms. Suicide attempt was the leading cause of poisoning, with 62 cases (88.57% of total). Atropine administration was an effective therapeutic approach for treating signs and symptoms, which included sialorrhea (p=0.0006), nausea (p=0. 0029) and emesis (p lt0.0001). The use of activated charcoal was shown effective, both in combating the signs and symptoms presented by both patient groups (p <0.0001). Conclusion: it is concluded that the use of atropine and activated charcoal is highly effective to treat the signs and symptoms developed by patients presenting acute exogenous intoxication by carbamates or organophosphates.

Recent advances in the treatment of hyperammonemia

Ammonia is a neurotoxic agent that is primarily generated in the intestine and detoxified in the liver. Toxic increases in systemic ammonia levels predominantly result from an inherited or acquired impairment in hepatic detoxification and lead to potentially life-threatening neuropsychiatric symptoms. Inborn deficiencies in ammonia detoxification mainly affect the urea cycle, an endogenous metabolic removal system in the liver. Hepatic encephalopathy, on the other hand, is a hyperammonemia-related complication secondary to acquired liver function impairment. A range of therapeutic options is available to target either ammonia generation and absorption or ammonia removal. Therapies for hepatic encephalopathy decrease intestinal ammonia production and uptake. Treatments for urea cycle disorders eliminate ammoniagenic amino acids through metabolic transformation, preventing ammonia generation. Therapeutic approaches removing ammonia activate the urea cycle or the second essential endogenous ammonia detoxification system, glutamine synthesis. Recent advances in treating hyperammonemia include using synergistic combination treatments, broadening the indication of orphan drugs, and developing novel approaches to regenerate functional liver tissue. This manuscript reviews the various pharmacological treatments of hyperammonemia and focuses on biopharmaceutical and drug delivery issues.

A multifaceted approach to calcium channel blocker overdose: a case report and literature review

Calcium channel blocker toxicity can be devastating. Initial therapy with fluid, calcium, and adrenoreceptor agonists should be prompt and novel therapies can be added if no response. Determining cardiogenic shock versus vasoplegia with echocardiogram or other hemodynamic monitoring may guide treatment options.

Folic acid-conjugated TiO2-doped mesoporous carbonaceous nanocomposites loaded with Mitoxantrone HCl for chemo-photodynamic therapy

A TiO₂-doped porous carbon drug delivery system was prepared. The ability of this system to combine chemotherapy with photodynamic activity enhanced the cancer cell killing effect.

Should computerised tomography replace endoscopy in the evaluation of symptomatic ingestion of corrosive substances?

INTRODUCTION

Corrosive ingestions are common, although most ingestions do not result in clinically significant effects. Limited guidance is available on the role of endoscopy and/or computerised tomography (CT) in the investigation of individuals with corrosive ingestion, and the present data regarding predictors of poor outcome are confusing. Furthermore, whilst there are many case series describing the use of endoscopy in corrosive ingestions, no clear ideal time frame has been established as to when it should be undertaken. More recently, CT has been used to grade injuries, but there are few studies on its role in managing corrosive injuries, and those studies that have been reported are conflicting in their results.

METHODS

A Medline search was performed with the terms 'Caustic ingestion' and 'Corrosive ingestion' and a second search by adding the words 'Endoscopy', 'CT', and 'Computerised tomography' as a subject term or keyword. These searches revealed a total of 277 reviews and papers, of which 33 original papers were relevant for analysis. Three further papers were identified during the analysis of these papers and a PubMed search of the same terms added one further paper, bringing the total to 37. There have been no prospective, randomised controlled trials directly comparing endoscopy and CT. Only two retrospective studies compared the use of CT and that of endoscopy. Thirty-five studies examined whether an endoscopy is always needed, and if so, within what time frame this should be done: CT or endoscopy? A review of these studies suggests that the data regarding the use of CT in these circumstances are not yet of sufficient weight to replace endoscopy as the first-line investigation in corrosive ingestion-related injury. Who needs investigation after corrosive ingestion? We believe that signs and symptoms indicate the likelihood of clinically significant injury in adults. Specifically, any evidence of oropharyngeal burns, drooling, vomiting, pain or dysphagia clearly indicates the need for an endoscopy. In children, it appears that an even greater degree of caution is needed. How soon after ingestion should investigation be performed? For whom an endoscopy is required, it is prudent to enable surgery and other specifics regarding management of corrosives to be decided quickly (< 12 h). There are many incidences where endoscopy has been done safely beyond 48 h although this is not needed frequently. Management recommendations Asymptomatic patients, particularly adults with a normal clinical examination and who can eat and drink normally, can be discharged safely without endoscopy. Endoscopy is preferred over CT in the assessment of risk in symptomatic patients with corrosive ingestion. If patients have any oropharyngeal injury and in particular symptoms of drooling, vomiting, dysphagia or pain (retrosternal or otherwise), the risk of having a high-grade injury is higher, and urgent endoscopy should be performed to grade the injury and determine whether surgical intervention is required. Patients who have non-specific symptoms, such as cough, should also undergo endoscopy, but this is less urgent.

CONCLUSIONS

Despite the lack of high-quality clinical trial data, the available evidence and clinical experience support the use of early endoscopy (< 12 h) in patients who are symptomatic after ingestion of a corrosive substance. We propose a clinical guideline that can be used to help plan management of corrosives.

Synthesis of highly crystalline sp2-bonded boron nitride aerogels

sp(2)-Bonded boron nitride aerogels are synthesized from graphene aerogels via carbothermal reduction of boron oxide and simultaneous nitridation. The color and chemical composition of the original gel change dramatically, while structural features down to the nanometer scale are maintained, suggesting a direct conversion of the carbon lattice to boron nitride. Scanning and transmission electron microscopies reveal a foliated architecture of wrinkled sheets, a unique morphology among low-density, porous BN materials. The converted gels display a high degree of chemical purity (>95%) and crystalline order and exhibit unique cross-linking structures.

Common causes of poisoning: etiology, diagnosis and treatment

BACKGROUND

In 2011, German hospitals treated approximately 205 000 patients suffering from acute poisoning. Change is seen over time both in the types of poisoning that occur and in the indications for specific treatment.

METHODS

This article is based on a selective review of the literature, with special attention to the health reports of the German federal government, the annual reports of the GIZ-Nord Poisons Center (the poison information center for the four northwestern states of Germany, i.e. Bremen, Hamburg, Lower Saxony and Schleswig-Holstein), and the recommendations of international medical associations.

RESULTS

From 1996 to 2011, the GIZ-Nord Poisons Center answered more than 450 000 inquiries, most of which involved exposures to medical drugs, chemicals, plants, foods, or cosmetics. Poisoning was clinically manifest in only a fraction of these cases. Ethanol intoxication is the commonest type of acute poisoning and suicide by medical drug overdose is the commonest type of suicide by poisoning. Death from acute poisoning is most commonly the result of either smoke inhalation or illegal drug use. Severe poisoning is only rarely due to the ingestion of chemicals (particularly detergents and cleaning products), cosmetics, or plant matter. Medical procedures that are intended to reduce the absorption of a poison or enhance its elimination are now only rarely indicated. Antidotes (e.g., atropine, 4-dimethylaminophenol, naloxone, toluidine blue) are available for only a few kinds of poisoning. Randomized clinical trials of treatment have been carried out for only a few substances.

CONCLUSION

Most exposures to poisons can be treated with general emergency care and, if necessary, with symptomatic intensive-care measures. Poison information centers help ensure that cases of poisoning are dealt with efficiently. The data they collect are a useful aid to toxicological assessment and can serve as a point of departure for research projects.

[Charcoal, cocaine and rattlesnakes: evidence-based treatment of poisoning]

BACKGROUND

Since ancient times poisoning has been treated medicinally. Clinical toxicology, in the narrow sense of the term, developed from the foundation of specialized medical treatment units for poisoning and the formation of the first poison information centers in the second half of the twentieth century. Historically, the first poison information centers were often localized at pediatric clinics or departments of internal medicine. It became increasingly more obvious that this pooling of competences made sense.

AIM

This article gives a general introduction in clinical toxicology and presents the functions and key activities of emergency poison centers.

MATERIAL AND METHODS

The organisation and work of a poisons centre is demonstrated on the basis of the Poisons Information Center (GIZ) North annual report for 2011. In a short summary the basic principles of clinical toxicology are elucidated: the primary removal of poisons by gastric lavage and administration of activated charcoal, secondary removal of poisons by enhanced elimination using hemodialysis, hemoperfusion, multi-dose activated charcoal and molecular adsorbent recirculating systems (MARS) and the indications for administration of specific antidotes or antivenins (antisera against poisoning by poisonous animals).

RESULTS

Gastric lavage is indicated within 1 h after ingestion of a potentially life-threatening dose of a poison. In cases of poisoning with substances which penetrate the central nervous system (CNS) gastric lavage should be performed only after endotracheal intubation due to the risk of aspiration. The basic management of poisoned patients by emergency medicine personnel out of hospital and on the way to hospital is presented. The Bremen list, a compilation of the five antidotes, atropine, 4-dimethylaminophenol (4-DMAP), tolonium chloride, naloxone and activated charcoal for out of hospital treatment by emergency doctors is presented.

CONCLUSION

In all, even questionable cases of poisoning consultation at emergency poison centers is recommended. An extensive list of all German speaking poison information centers is available on the homepage of GIZ-Nord (http://www.giz-nord.de).

Of pills, plants, and paraquat: the relevance of poison centers in emergency medicine

The organization and work of a poisons center are demonstrated on the basis of GIZ-Nord Poisons Center Annual Report for 2011. In a short summary the basic principles of clinical toxicology are elucidated: the indications for gastric lavage and the application of activated charcoal. Moreover the means of enhanced elimination are presented: hemodialysis, hemoperfusion, multi-dose activated charcoal and molecular absorbent recirculating system (MARS). Gastric lavage is indicated within one hour after ingestion of a life-threatening dose of a poison. In intoxications with CNS penetrating substances gastric lavage should be performed only after endotracheal intubation due to the risk of aspiration. The basic management of the intoxicated patient by emergency medicine personnel out of hospital and on the way into the hospital is presented. The "Bremen List", a compilation of five antidotes (atropine, 4-DMAP, tolonium chloride, naloxone, activated charcoal) for the out of hospital treatment by emergency doctors is introduced.

A case report of opium body packer; review of the treatment protocols and mechanisms of poisoning

ABSTRACT Body packers are people who illegally carry drugs, mostly cocaine as well as opium and/or heroin, concealed within their bodies. The packets are inserted in the mouth, rectum, or vagina in order to get across borders without being detected. In this presentation we report a case of an opium body packer and review the available scientific literature by focusing on mechanisms of toxicity and treatment approach. The patient was a 35-year-old man who had lethargy, respiratory depression, tachycardia, normal blood pressure, hyperthermia, and pinpoint pupils on presentation. No past medical history was obtained and the only positive history was his travel from Afghanistan 2 days earlier, which he had given to emergency personnel before arriving at our hospital. Complete blood cells and kidney and liver tests were all in normal range. In the emergency department, the patient was treated with oxygen, naloxone, and hypertonic glucose. One dose of activated charcoal (1 g/kg) was administered orally. After intravenous injection of naloxone (4 mg), the lethargy, respiratory depression, and miosis were resolved. The patient was admitted to the intensive care unit and 90 min after admission, the patient redeveloped respiratory distress and lost consciousness. He was intubated and mechanically ventilated due to the suspicious of body packing. Plain abdominal x-ray showed multiple packets throughout the gastrointestinal tract; 81 packets were removed by surgery and three of them were left due to leaking. After removing the packets, the patient was treated conservatively. He suffered a pulmonary infection (aspiration pneumonia) and he regained consciousness after 4 days. Upon recovery the patient was seen by a psychiatrist prior to going to prison. Surgery is recommended for body packers who have significant signs or symptoms.

Indications for single-dose activated charcoal administration in acute overdose

PURPOSE OF REVIEW

Gastrointestinal decontamination in overdose patients remains a controversial problem in emergency medicine. There has been a significant decrease in the use of single-dose activated charcoal (SDAC) in recent years based on little new evidence and possibly because the overall mortality in overdose patients is low.

RECENT FINDINGS

Human volunteer studies suggest SDAC is effective and this effect occurs for up to 4 h after ingestion, but the magnitude of the reduction in area under the curve (AUC) decreases over time. Two randomized controlled trials including one recent large study did not find SDAC to be beneficial. Pharmacokinetic and pharmacodynamic studies of specific drugs in overdose suggest that for most drugs SDAC decreases drug exposure, but this does not translate to clinical benefit in all cases. The administration of SDAC is a low-risk intervention.

SUMMARY

Although SDAC is unlikely to be beneficial in many overdose patients, for some subgroups with severe poisoning, the benefits will outweigh the low risk of administration. The use of SDAC should be based on the potential toxicity of the drug ingested and the potential benefit of SDAC balanced against the willingness of the patient to take SDAC and the low risk of administration.

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.

The effect of decontamination procedures on the pharmacodynamics of venlafaxine in overdose

AIMS

To investigate the relationship between decontamination procedures and seizure events caused by venlafaxine overdose and to estimate the time at which 90% of patients would have had their first seizure in the presence and absence of decontamination.

METHODS

Data were collected from 319 patients who took an overdose of venlafaxine on 436 occasions. Seizures occurred on 24 of 436 occasions (5%). Patients received one of single dose activated charcoal (SDAC), whole bowel irrigation (WBI), a combination of either (SDAC/WBI) or no decontamination. Logistic regression and time to event analysis were used to investigate the influence of dose and decontamination on the probability of seizures and time to 90% (t(90) ) of seizure, respectively.

RESULTS

A linear logistic regression model described the data. Simulation from the model showed that the probability of seizure was 0.05 (0.03-0.08), 0.19 (0.09-0.35) and 0.75 (0.30-0.96) at 1000, 5000 and 10 000 mg, respectively (median and 95% credible interval). At the mean dose of 2100 mg the odds ratios (OR) in the presence of SDAC, WBI and SDAC/WBI were 0.48 (0.25-0.89), 0.71 (0.35-1.22) and 0.25 (0.08-0.62), respectively. A modified Gompertz model described the time to seizure events. Simulations from the Gompertz model showed that the t(90) values for first seizure was 26 h and was not affected by dose or decontamination procedure.

CONCLUSION

SDAC/WBI provided greater benefits than the sum of the independent effects of SDAC and WBI. Patients should be observed for at least 24 h for seizures based on the dose and risk of seizure occurring.

Principles of antidote pharmacology: an update on prophylaxis, post-exposure treatment recommendations and research initiatives for biological agents

The use of biological agents has generally been confined to military-led conflicts. However, there has been an increase in non-state-based terrorism, including the use of asymmetric warfare, such as biological agents in the past few decades. Thus, it is becoming increasingly important to consider strategies for preventing and preparing for attacks by insurgents, such as the development of pre- and post-exposure medical countermeasures. There are a wide range of prophylactics and treatments being investigated to combat the effects of biological agents. These include antibiotics (for both conventional and unconventional use), antibodies, anti-virals, immunomodulators, nucleic acids (analogues, antisense, ribozymes and DNAzymes), bacteriophage therapy and micro-encapsulation. While vaccines are commercially available for the prevention of anthrax, cholera, plague, Q fever and smallpox, there are no licensed vaccines available for use in the case of botulinum toxins, viral encephalitis, melioidosis or ricin. Antibiotics are still recommended as the mainstay treatment following exposure to anthrax, plague, Q fever and melioidosis. Anti-toxin therapy and anti-virals may be used in the case of botulinum toxins or smallpox respectively. However, supportive care is the only, or mainstay, post-exposure treatment for cholera, viral encephalitis and ricin - a recommendation that has not changed in decades. Indeed, with the difficulty that antibiotic resistance poses, the development and further evaluation of techniques and atypical pharmaceuticals are fundamental to the development of prophylaxis and post-exposure treatment options. The aim of this review is to present an update on prophylaxis and post-exposure treatment recommendations and research initiatives for biological agents in the open literature from 2007 to 2009.

Hypotension in severe dimethoate self-poisoning

Introduction

Acute self-poisoning with the organophosphorus (OP) pesticide dimethoate has a human case fatality three-fold higher than poisoning with chlorpyrifos despite similar animal toxicity. The typical clinical presentation of severe dimethoate poisoning is quite distinct from that of chlorpyrifos and other OP pesticides: many patients present with hypotension that progresses to shock and death within 12–48 h post-ingestion. The pathophysiology of this syndrome is not clear.

Case reports

We present here three patients with proven severe dimethoate poisoning. Clinically, all had inappropriate peripheral vasodilatation and profound hypotension on presentation, which progressed despite treatment with atropine, i.v. fluids, pralidoxime chloride, and inotropes. All died 2.5–32 h post-admission. Continuous cardiac monitoring and quantification of troponin T provided little evidence for a primary cardiotoxic effect of dimethoate.

Conclusion

Severe dimethoate self-poisoning causes a syndrome characterized by marked hypotension with progression to distributive shock and death despite standard treatments. A lack of cardiotoxicity until just before death suggests that the mechanism is of OP-induced low systemic vascular resistance (SVR). Further invasive studies of cardiac function and SVR, and post-mortem histology, are required to better describe this syndrome and to establish the role of vasopressors and high-dose atropine in therapy.

Thoracic spine compression fracture during isoniazid-induced seizures: case report

We report here an 11-year-old previously healthy girl with isoniazid intoxication who sustained a seizure-induced thoracic compression fracture. The following might be the first such case reported in the medical literature. Isoniazid toxicity should be suspected in any patient who comes to the emergency department with refractory seizures and metabolic acidosis. Forceful muscle contractions during a convulsive seizure can result in vertebral compression fracture, especially in the midthoracic region. A complaint of back pain after isoniazid-induced seizures in patients raises a strong suspicion of vertebral fracture and should be evaluated radiologically.

Differences in treatment advice for common poisons by poisons centres – An international comparison

OBJECTIVE

To investigate how poisons centres advise on management of common drug poisonings and compare advice on gut decontamination with the EAPCCT/AACT Position Statements.

METHODS

An interactive questionnaire was sent to 14 poisons centres asking about working practices, "top 20" enquiries in 2002, and management of 4 specific drug poisonings.

RESULTS

Replies were received from centres in 11 countries. Annual telephone enquiry numbers varied from 620 (Sri Lanka) to over 50,000 (Germany for 2000). Recommendations for gut decontamination for acetaminophen poisoning were: activated charcoal (AC) alone (5 centres); gastric lavage (GL) alone (1); AC and/or GL (3); AC, GL and/or ipecac (2). Only 40% (4/10) recommended AC and 50% (3/6) GL within 1 hour. Intervention doses for gut decontamination ranged from 100-200 mg/kg (nine centres) and for "high-risk" groups 75-100 mg/kg (3). Plasma concentration for N-acetylcysteine (NAC) treatment ranged from 150 mg/L (four centres) to 200 mg/L (6) at 4 hours. Results were similarly varied for three other common drug poisons (benzodiazepines, amitriptyline, and paroxetine).

CONCLUSIONS

Most poisons centres have protocols that differ in terms of gut decontamination, timing, and intervention doses. Many centres recommend charcoal or gastric lavage after the 1-hour limit proposed in the Position Statements. There is scope for rationalization of approaches to the management of common poisons.