Multiple-dose activated charcoal for treatment of yellow oleander poisoning: a single-blind, randomised, placebo-controlled trial

Analytical quantification of the plant specific cardiac glycosides in biological fluids in a rare case of yellow oleander (Cascabela thevetia) self-poisoning in Italy

Yellow oleander contains digoxin-like cardiac glycosides that frequently cause intoxications in Sri Lanka and India. To date, though, no exposure has been analytically confirmed and quantitative determination of the plant specific glycosides in human biological fluids was never performed. We report an unusual case of self-poisoning in a young female in Italy who ingested 9 crushed seeds of Cascabela thevetia and was admitted to the emergency room with a 2nd degree atrio-ventricular block at the ECG. The case was managed with activated charcoal, repeated doses of anti-digoxin immune Fab and supportive care. A transient thrombocytopenia developed and resolved within a few days. Ultra-high performance liquid chromatography coupled with tandem mass spectrometry was used for the determination and quantification of thevetin A, thevetin B and peruvoside in plasma and urine. Thevetin A and thevetin B, two of the primary glycosides in the seeds, were not present in any of the samples, while detectable levels of the metabolite peruvoside were found in all biological samples on day 1 and 3. Digitoxigenin, the aglycone of thevetin B, was also identified using a semi-untargeted analysis. This is the first report of a quantitative determination of cardiac glycosides of yellow oleander in blood and urine. The finding may support very early administration of activated charcoal to possibly prevent further formation of secondary, and possibly more potent, glycosides and limit toxicity.

Dietary bamboo charcoal powder ameliorates high-fat diet-induced hyperlipidemia by enhancing fecal lipid excretions in Sprague-Dawley rats

Introduction

Bamboo charcoal powder (BCP) is increasingly used as a food colorant. This study aims to evaluate the effects of BCP consumption on improving high-fat diet-induced hyperlipidemia.

Methods

Fifty male SD rats were randomly assigned into five groups, with 10 rats in each group: the control group was fed a low-fat diet (LFD); the model control group was fed a high-fat diet (HFD); the low-BCP dose group was fed a HFD and given 2.81 g of BCP/kg of body weight (BCP-L) by gavage; the medium-BCP dose group was fed a HFD and given 5.62 g of BCP/kg of body weight (BCP-M) by gavage; the high-BCP dose group was fed a HFD and given 11.24 g of BCP/kg of body weight (BCP-H) by gavage.

Results

After 90 days, the consumption of BCP caused a decrease in body weight, plasma lipids (triglyceride, cholesterol, and low-density lipoprotein (LDL)), liver triglyceride, and cholesterol levels, and liver histopathological scores. BCP caused a significant increase in superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) in liver tissues. BCP also led to an increase in 72-h fecal dry weight and crude fat in a rat metabolic cage. The analysis of fecal samples with liquid chromatography time-of-flight mass spectrometry (LC-Q-TOF-MS) showed that the biomarkers associated with BCP consumption were mainly related to fatty and amino acid metabolism. Notably, BCP treatment significantly promoted linoleic acid metabolism.

Discussion

These results suggest that BCP may have a preventive effect against diet-induced hyperlipidemia through the promotion of fecal fat excretion. BCP may potentially be used as an alternative functional food component for people with diet-induced hyperlipidemia.

Antidote use for cardiac arrest or hemodynamic instability due to cardiac glycoside poisoning: A narrative review

Introduction

Cardiac glycosides comprise medications such as digoxin and digitoxin, plants, and even certain toad venoms. Intoxication with cardiac glycosides can lead to hemodynamic instability and cardiac arrest. With this narrative review, our objective was to determine if any therapy used in a near-cardiac arrest state due to cardiac glycoside poisoning could improve survival with favourable functional and neurological outcomes.

Methods

We searched the Medline, PubMed, EMBASE and Cochrane Library databases up to February 2022 for controlled trials, observational studies, and case reports. We reviewed studies if participants were exposed to a cardiac glycoside, had hemodynamic instability, and an intervention was attempted to reverse the toxicity. The effect of interventions on (1) survival with favourable functional and neurological outcomes and (2) correction of hemodynamic instability was assessed.

Results

Of the 2422 studies found, 73 were included for analysis, of which 58 were case reports or series, and 15 were observational cohorts. Most patients were intoxicated with medication (60 individual cases and 11 observational cohorts). Administration of digoxin immune-Fab fragments was associated with improved hemodynamic status and survival in medication patients. Administration of magnesium, cardioversion, and cardiac pacing was associated with favourable outcomes, while administration of atropine, antiarrhythmics, or calcium was not.

Conclusion

In patients with hemodynamic instability due to cardiac glycoside intoxication, digoxin immune-Fab fragments should be given, and magnesium administration, cardioversion, and cardiac pacing can reasonably be attempted.

Indian Society of Critical Care Medicine Position Statement: Approach to a Patient with Poisoning in the Emergency Room and Intensive Care Unit

Poisoning and its aftermath are globally observed and acknowledged concerns. India has a large burden of "self-harm/suicides" with 12.4/per 100,000 population committing suicide. Consumption of poisonous substances is the second most common mode of self-harm in India. Patients present to both public and private institutions in a critically ill state. The Indian Society of Critical Care Medicine (ISCCM) and Indian College of Critical Care Medicine (ICCCM) decided to address common and contentious issues related to poisoning by developing a position statement that is expected to be appropriate in the Indian scenario by the constitution of an "expert group" to provide a "set of statements" aimed at addressing the common issues faced by intensivists in their practice in managing such patients. The structured approach, framework, and process adopted in developing the position statement on the approach to poisoning have been detailed in this statement. The formation of an expert advisory panel was followed by a literature search, and multiple sessions of consensus-building exercises to reach the current statement presented below. The statement consists of relevant questions with possible answers thereof. Each answer was further weighed against the data and evidence available in the literature. Recommendations were made using a simplified score to make the statement qualitatively meaningful.

How to cite this article

Rungta N, Ray B, Bhalla A, DP Samaddar, Paul G, Prasad S, et al. Indian Society of Critical Care Medicine Position Statement: Approach to a Patient with Poisoning in the Emergency Room and Intensive Care Unit. Indian J Crit Care Med 2024;28(S2):S217-S232.

Positive single-center randomized trials and subsequent multicenter randomized trials in critically ill patients: a systematic review

BACKGROUND

It is unclear how often survival benefits observed in single-center randomized controlled trials (sRCTs) involving critically ill patients are confirmed by subsequent multicenter randomized controlled trials (mRCTs). We aimed to perform a systemic literature review of sRCTs with a statistically significant mortality reduction and to evaluate whether subsequent mRCTs confirmed such reduction.

METHODS

We searched PubMed for sRCTs published in the New England Journal of Medicine, JAMA, or Lancet, from inception until December 31, 2016. We selected studies reporting a statistically significant mortality decrease using any intervention (drug, technique, or strategy) in adult critically ill patients. We then searched for subsequent mRCTs addressing the same research question tested by the sRCT. We compared the concordance of results between sRCTs and mRCTs when any mRCT was available. We registered this systematic review in the PROSPERO International Prospective Register of Systematic Reviews (CRD42023455362).

RESULTS

We identified 19 sRCTs reporting a significant mortality reduction in adult critically ill patients. For 16 sRCTs, we identified at least one subsequent mRCT (24 trials in total), while the interventions from three sRCTs have not yet been addressed in a subsequent mRCT. Only one out of 16 sRCTs (6%) was followed by a mRCT replicating a significant mortality reduction; 14 (88%) were followed by mRCTs with no mortality difference. The positive finding of one sRCT (6%) on intensive glycemic control was contradicted by a subsequent mRCT showing a significant mortality increase. Of the 14 sRCTs referenced at least once in international guidelines, six (43%) have since been either removed or suggested against in the most recent versions of relevant guidelines.

CONCLUSION

Mortality reduction shown by sRCTs is typically not replicated by mRCTs. The findings of sRCTs should be considered hypothesis-generating and should not contribute to guidelines.

Oleander-Associated Keratitis and Uveitis

PURPOSE

Oleander is a poisonous plant with extensively documented systemic side effects; however, oleander's ophthalmic side effects have not been detailed in the literature. We report a case of oleander-associated keratitis with subsequent corneal edema and anterior uveitis.

METHODS

This is a case report and review of relevant literature.

RESULTS

A 58-year-old woman presented with large corneal epithelial defect after being struck in the eye with an oleander leaf. Despite treatment with topical moxifloxacin, she developed severe corneal edema and anterior uveitis. A diagnosis of oleander-associated ocular inflammation with secondary corneal edema was made, given the temporal relationship, and treatment was initiated with topical prednisolone and cyclopentolate. However, the corneal edema and inflammation continued to progress until oral prednisone and topical difluprednate were initiated. Visual acuity, anterior uveitis, and corneal edema significantly improved with aggressive immunomodulation. Follow-up at 1 month confirmed complete recovery of symptoms, corneal edema and anterior uveitis.

CONCLUSIONS

Severe corneal edema and anterior uveitis can be associated with oleander exposure. Aggressive treatment with oral and topical steroids may be required without persistent sequelae at the 5-month follow-up. Ophthalmologists should consider this inflammatory reaction if patients experience ocular exposure to oleander.

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.

Activated Charcoal and Poisoning: Is It Really Effective?

BACKGROUND

This study aims to compare the poisoned patients who could not be administered activated charcoal because of its unavailability with the poisoned patients who were administered charcoal in the later period and to reveal the results about its effectiveness.

STUDY QUESTION

Is the use of activated charcoal effective against poisoning caused by oral medication?

STUDY DESIGN

This retrospective cohort study with historical control was planned at a tertiary hospital. Patients older than 18 years were admitted to the emergency department because of oral drug poisoning during the study periods. A total of 1159 patients who were not given activated charcoal and 877 patients who were given activated charcoal were included in this study.

MEASURES AND OUTCOMES

The frequency of clinical findings secondary to the drug taken, the frequency of antidote use, the frequency of intubation, and the hospitalization length were determined as clinical outcome parameters.

RESULTS

There was no statistically significant difference in the development of central nervous system findings, cardiovascular system findings, frequency of intubation, and blood gas disorders, as well as the length of hospitalization periods according to the activated charcoal application. Hepatobiliary system findings and electrolyte disturbances were found to be less common in patients given activated charcoal. The frequency of tachycardia, speech impairment, coma, and respiratory acidosis was found to be statistically higher in patients who were administered activated charcoal. The hospitalization period of the patients who were given activated charcoal was longer in patients with drug findings; however, there was no difference in the hospitalization periods of the patients who were given an antidote.

CONCLUSIONS

The use of activated charcoal in poisoned patients may not provide sufficient clinical benefits. However, clinical studies with strong evidence levels are needed to determine activated charcoal's clinical efficacy, which is still used as a universal antidote.

The effect of activated charcoal on drug exposure following intravenous administration: A meta-analysis

Activated charcoal both reduces primary drug absorption and enhances drug elimination. However, the two mechanisms of action overlap and are indistinguishable from each other. In order to estimate the extend of enhanced elimination, we summarized the effect of activated charcoal on intravenously administered drugs, where reduced drug exposure can be attributed to enhanced elimination. We performed a meta-analysis of randomized controlled studies evaluating the effect of orally administered activated charcoal on the systemic exposure of intravenously administered drugs. We searched the bibliographic databases PubMed, Embase and Cochrane. Meta-regression analyses of selected physiochemical drug properties on the effect sizes of activated charcoal were performed. All but one of 21 included studies used multiple-dose activated charcoal (MDAC). MDAC reduced the median half-life of the intravenously administered study drugs by 45.7% (interquartile range: 15.3%-51.3%) and area under the concentration time curve by 47.0% (interquartile range: 36.4%-50.2%). MDAC significantly improved drug elimination across nine different intravenously administered drugs, but we were unable to identify factors allowing extrapolation to other drugs. The results offer a possible and plausible rationale for the previously observed effects of single-dose activated charcoal beyond the timeframe where ingested drug is present in the gastro-intestinal tract.

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.

Acute oleander poisoning: A study of clinical profile from a tertiary care center in South India

Introduction:

Yellow oleander (Thevetia peruviana), which belongs to the Apocyanaceae family, is a common shrub seen throughout the tropics. All parts of the plant contain high concentrations of cardiac glycosides which are toxic to cardiac muscle and the autonomic nervous system. Here, we describe the clinical profile of patients with oleander poisoning and their outcomes.

Methods and Materials:

This retrospective study was conducted over a period of 12 months (March 2016 to February 2017). The data was extracted from the inpatient electronic medical records. Adult patients with a diagnosis of acute yellow oleander poisoning were included in the study. Descriptive statistics were obtained for all variables in the study and appropriate statistical tests were employed to ascertain their significance.

Results:

The study comprised 30 patients aged 30.77 ± 12.31 (mean ± SD) who presented at 12.29 ± 8.48 hours after consumption of yellow oleander. Vomiting (80%) was the most common presenting symptom. Metabolic abnormalities at presentation included hyperchloremia in 22 patients and metabolic acidosis (bicarbonate <24 mmol/L) in 29 patients. Fifteen (50%) patients had abnormal ECG, of which second-degree AV block was the commonest ECG abnormality seen in 4 (13.3%). Fifteen (50%) patients had transvenous temporary pacemaker insertion (TPI). Having a TPI significantly prolonged the duration of hospital stay (OR 1.85, 95% CI 1.06–3.21, P 0.03). The mortality in the cohort was 2 (6.7%).

Conclusion:

In patients with yellow oleander poisoning, dyselectrolytemia with ECG abnormalities was common. TPI prolonged the duration of hospital stay. Further studies are required to know the indication for and to ascertain the effect of temporary pacing on survival.

Oleander and Datura Poisoning: An Update

India has a very high incidence of poisoning. While most cases are due to chemicals or drugs or envenomation by venomous creatures, a significant proportion also results from consumption or exposure to toxic plants or plant parts or products. The exact nature of plant poisoning varies from region to region, but certain plants are almost ubiquitous in distribution, and among these, Oleander and Datura are the prime examples. These plants are commonly encountered in almost all parts of India. While one is a wild shrub (Datura) that proliferates in the countryside and by roadsides, and the other (Oleander) is a garden plant that features in many homes. Incidents of poisoning from these plants are therefore not uncommon and may be the result of accidental exposure or deliberate, suicidal ingestion of the toxic parts. An attempt has been made to review the management principles with regard to toxicity of these plants and survey the literature in order to highlight current concepts in the treatment of poisoning resulting from both plants.

First aid interventions by laypeople for acute oral poisoning

BACKGROUND

Oral poisoning is a major cause of mortality and disability worldwide, with estimates of over 100,000 deaths due to unintentional poisoning each year and an overrepresentation of children below five years of age. Any effective intervention that laypeople can apply to limit or delay uptake or to evacuate, dilute or neutralize the poison before professional help arrives may limit toxicity and save lives.

OBJECTIVES

To assess the effects of pre-hospital interventions (alone or in combination) for treating acute oral poisoning, available to and feasible for laypeople before the arrival of professional help.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, ISI Web of Science, International Pharmaceutical Abstracts, and three clinical trials registries to 11 May 2017, and we also carried out reference checking and citation searching.

SELECTION CRITERIA

We included randomized controlled trials comparing interventions (alone or in combination) that are feasible in a pre-hospital setting for treating acute oral poisoning patients, including but potentially not limited to activated charcoal (AC), emetics, cathartics, diluents, neutralizing agents and body positioning.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed study selection, data collection and assessment. Primary outcomes of this review were incidence of mortality and adverse events, plus incidence and severity of symptoms of poisoning. Secondary outcomes were duration of symptoms of poisoning, drug absorption, and incidence of hospitalization and ICU admission.

MAIN RESULTS

We included 24 trials involving 7099 participants. Using the Cochrane 'Risk of bias' tool, we assessed no study as being at low risk of bias for all domains. Many studies were poorly reported, so the risk of selection and detection biases were often unclear. Most studies reported important outcomes incompletely, and we judged them to be at high risk of reporting bias.All but one study enrolled oral poisoning patients in an emergency department; the remaining study was conducted in a pre-hospital setting. Fourteen studies included multiple toxic syndromes or did not specify, while the other studies specifically investigated paracetamol (2 studies), carbamazepine (2 studies), tricyclic antidepressant (2 studies), yellow oleander (2 studies), benzodiazepine (1 study), or toxic berry intoxication (1 study). Eighteen trials investigated the effects of activated charcoal (AC), administered as a single dose (SDAC) or in multiple doses (MDAC), alone or in combination with other first aid interventions (a cathartic) and/or hospital treatments. Six studies investigated syrup of ipecac plus other first aid interventions (SDAC + cathartic) versus ipecac alone. The collected evidence was mostly of low to very low certainty, often downgraded for indirectness, risk of bias or imprecision due to low numbers of events.First aid interventions that limit or delay the absorption of the poison in the bodyWe are uncertain about the effect of SDAC compared to no intervention on the incidence of adverse events in general (zero events in both treatment groups; 1 study, 451 participants) or vomiting specifically (Peto odds ratio (OR) 4.17, 95% confidence interval (CI) 0.30 to 57.26, 1 study, 25 participants), ICU admission (Peto OR 7.77, 95% CI 0.15 to 391.93, 1 study, 451 participants) and clinical deterioration (zero events in both treatment groups; 1 study, 451 participants) in participants with mixed types or paracetamol poisoning, as all evidence for these outcomes was of very low certainty. No studies assessed SDAC for mortality, duration of symptoms, drug absorption or hospitalization.Only one study compared SDAC to syrup of ipecac in participants with mixed types of poisoning, providing very low-certainty evidence. Therefore we are uncertain about the effects on Glasgow Coma Scale scores (mean difference (MD) -0.15, 95% CI -0.43 to 0.13, 1 study, 34 participants) or incidence of adverse events (risk ratio (RR) 1.24, 95% CI 0.26 to 5.83, 1 study, 34 participants). No information was available concerning mortality, duration of symptoms, drug absorption, hospitalization or ICU admission.This review also considered the added value of SDAC or MDAC to hospital interventions, which mostly included gastric lavage. No included studies investigated the use of body positioning in oral poisoning patients.First aid interventions that evacuate the poison from the gastrointestinal tractWe found one study comparing ipecac versus no intervention in toxic berry ingestion in a pre-hospital setting. Low-certainty evidence suggests there may be an increase in the incidence of adverse events, but the study did not report incidence of mortality, incidence or duration of symptoms of poisoning, drug absorption, hospitalization or ICU admission (103 participants).In addition, we also considered the added value of syrup of ipecac to SDAC plus a cathartic and the added value of a cathartic to SDAC.No studies used cathartics as an individual intervention.First aid interventions that neutralize or dilute the poison No included studies investigated the neutralization or dilution of the poison in oral poisoning patients.The review also considered combinations of different first aid interventions.

AUTHORS' CONCLUSIONS

The studies included in this review provided mostly low- or very low-certainty evidence about the use of first aid interventions for acute oral poisoning. A key limitation was the fact that only one included study actually took place in a pre-hospital setting, which undermines our confidence in the applicability of these results to this setting. Thus, the amount of evidence collected was insufficient to draw any conclusions.

Poisoning by Herbs and Plants: Rapid Toxidromic Classification and Diagnosis

The American Association of Poison Control Centers has continued to report approximately 50,000 telephone calls or 8% of incoming calls annually related to plant exposures, mostly in children. Although the frequency of plant ingestions in children is related to the presence of popular species in households, adolescents may experiment with hallucinogenic plants; and trekkers and foragers may misidentify poisonous plants as edible. Since plant exposures have continued at a constant rate, the objectives of this review were (1) to review the epidemiology of plant poisonings; and (2) to propose a rapid toxidromic classification system for highly toxic plant ingestions for field use by first responders in comparison to current classification systems. Internet search engines were queried to identify and select peer-reviewed articles on plant poisonings using the key words in order to classify plant poisonings into four specific toxidromes: cardiotoxic, neurotoxic, cytotoxic, and gastrointestinal-hepatotoxic. A simple toxidromic classification system of plant poisonings may permit rapid diagnoses of highly toxic versus less toxic and nontoxic plant ingestions both in households and outdoors; direct earlier management of potentially serious poisonings; and reduce costly inpatient evaluations for inconsequential plant ingestions. The current textbook classification schemes for plant poisonings were complex in comparison to the rapid classification system; and were based on chemical nomenclatures and pharmacological effects, and not on clearly presenting toxidromes. Validation of the rapid toxidromic classification system as compared to existing chemical classification systems for plant poisonings will require future adoption and implementation of the toxidromic system by its intended users.

Single dose activated charcoal for gut decontamination: Application by medical non-professionals -a prospective study on availability and practicability

Context

Oral activated charcoal (AC) for toxin absorption should be applied as soon as possible. Extra-hospital AC-application on site by medical laypersons with pre-emptive obtained AC may save time, but may be inferior to AC-application by medical professionals.

Objective

1) Availability and incidence of pre-emptive stockpiling of AC on site in the German region Bavaria 2) time saved by AC-stockpiling and application on site, 3) quality of AC-application defined by completeness of the applied AC-dose, time needed, incidence of side-effects in lay-care and in professional-care, considering confounding variables: AC-formulation/powder/tablets, recommended AC-dose, patient’s age.

Method

telephone-interviews in cases with AC-recommendation by a Poison Information Centre (PIC). Lay-care was suggested according to risk-assessment by PIC. Ingestion sites were classified as either apt for AC-stockpiling or not apt.

Results

1) availability: In Bavaria only 20%–22% of eligible cases had AC on-hand, 2) time-saving was at least 14 min. 3) Lay-care/professional-care or patient’s age had no significant influence on the completeness of the applied AC-dose, which was higher with AC as powder but negatively correlated with the recommended AC-dose. No significant difference was seen with time needed for application and incidence of side-effects.

Conclusion

pre-emptive AC-stocking should be encouraged.

Fatal Oleander Toxicosis in Two Miniature Horses

Two young American miniature horses from the same farm were evaluated by a veterinarian due to presence of lethargy, anorexia, and cardiac arrhythmias. Both horses were treated aggressively with IV fluids and other supportive measures. The first horse died approximately 72 hr after the start of clinical signs and the second horse was humanely euthanized due to poor response to treatment. Oleander toxicosis was suspected based on the types of clinical signs present and due to several oleander plants and dried leaves present on the property. Oleander toxicosis was confirmed by the presence of oleandrin in gastrointestinal contents and digoxin in the serum of second horse.

Pharmacological treatment of cardiac glycoside poisoning

Cardiac glycosides are an important cause of poisoning, reflecting their widespread clinical usage and presence in natural sources. Poisoning can manifest as varying degrees of toxicity. Predominant clinical features include gastrointestinal signs, bradycardia and heart block. Death occurs from ventricular fibrillation or tachycardia. A wide range of treatments have been used, the more common including activated charcoal, atropine, β-adrenoceptor agonists, temporary pacing, anti-digoxin Fab and magnesium, and more novel agents include fructose-1,6-diphosphate (clinical trial in progress) and anticalin. However, even in the case of those treatments that have been in use for decades, there is debate regarding their efficacy, the indications and dosage that optimizes outcomes. This contributes to variability in use across the world. Another factor influencing usage is access. Barriers to access include the requirement for transfer to a specialized centre (for example, to receive temporary pacing) or financial resources (for example, anti-digoxin Fab in resource poor countries). Recent data suggest that existing methods for calculating the dose of anti-digoxin Fab in digoxin poisoning overstate the dose required, and that its efficacy may be minimal in patients with chronic digoxin poisoning. Cheaper and effective medicines are required, in particular for the treatment of yellow oleander poisoning which is problematic in resource poor countries.

Seed fall, seed predation, twigging and litter fall of Cascabela thevetia (L.) Lippold

Cascabela thevetia (L.) Lippold is a garden ornamental in northern Australia and two biotypes, the peach and the yellow, are recognised. In some areas it has naturalised and now has environmental and economic effects. As part of a broader research program into the ecology of C. thevetia, a field study was undertaken in northern Queensland to quantify seed fall and seed predation (by avian wildlife) of the peach biotype. The amount of twigging caused by birds while they fed on the seeds and the level of litter production were also recorded. Seed fall, seed predation, twigging and litter production occurred in all months of the year. Seed fall increased slowly over late spring and summer before peaking in mid- to late autumn (April–May) and then declining until October. Mean (± s.e.m.) estimated total annual seed fall was 19140 ± 2880 and 17030 ± 2930 seeds ha–1 in the first and second years respectively. Seed predation by birds was substantial, with 57% of all seeds predated. Birds also chewed an average of 600 twigs ha–1 year–1. Litter production varied from 430 to 950 kg dry weight (DW) ha–1 month–1. In total, 7900 ± 640 and 7390 ± 1420 kg (DW) litter was produced during the first and second years respectively. Although seed production of C. thevetia is less than a lot of other rangeland weeds, seed predation by birds further reduces the number of seeds entering the soil seed bank. The stem damage that occurred in conjunction with seed predation contributed to overall litter production and warrants further investigation in terms of its effect on plant growth.

Cardiotoxicodynamics: Toxicity of Cardiovascular Xenobiotics

Maintaining adequate tissue perfusion depends on a variety of factors, all of which can be influenced by xenobiotics (substances foreign to the body, including pharmaceuticals, chemicals, and natural compounds). Volume status, systemic vascular resistance, myocardial contractility, and cardiac rhythm all play a significant role in ensuring hemodynamic stability and proper cardiovascular function. Direct effects on the nervous system, the vasculature, or the heart itself as well as indirect metabolic effects may play a significant role in the development of cardiotoxicity. This article is dedicated to discussion of the disruption of cardiovascular physiology by xenobiotics.

Effect of sorbitol, single, and multidose activated charcoal administration on carprofen absorption following experimental overdose in dogs

OBJECTIVE

To compare the effectiveness of single dose activated charcoal, single dose activated charcoal with sorbitol, and multidose activated charcoal in reducing plasma carprofen concentrations following experimental overdose in dogs.

DESIGN

Randomized, four period cross-over study.

SETTING

University research setting.

ANIMALS

Eight healthy Beagles.

INTERVENTIONS

A 120 mg/kg of carprofen was administered orally to each dog followed by either (i) a single 2 g/kg activated charcoal administration 1 hour following carprofen ingestion (AC); (ii) 2 g/kg activated charcoal with 3.84 g/kg sorbitol 1 hour following carprofen ingestion (ACS); (iii) 2 g/kg activated charcoal 1 hour after carprofen ingestion and repeated every 6 hours for a total of 4 doses (MD); (iv) no treatment (control).

MEASUREMENTS AND MAIN RESULTS

Plasma carprofen concentrations were obtained over a 36-hour period following carprofen ingestion for each protocol. Pharmacokinetic modeling was performed and time versus concentration, area under the curve, maximum plasma concentration, time to maximum concentration, and elimination half-life were calculated and compared among the groups using ANOVA followed by Tukey's multiple comparisons test. Activated charcoal, activated charcoal with sorbitol (ACS), and multiple-dose activated charcoal (MD) significantly reduced the area under the curve compared to the control group. AC and MD significantly reduced the maximum concentration when compared to the control group. MD significantly reduced elimination half-life when compared to ACS and the control group. There were no other significant differences among the treatment groups.

CONCLUSIONS

Activated charcoal and ACS are as effective as MD in reducing serum carprofen concentrations following experimental overdose in dogs. Prospective studies are warranted to evaluate the effectiveness of AC, ACS, and MD in the clinical setting.

Retained drugs in the gastrointestinal tracts of deceased victims of oral drug overdose

CONTEXT

The extent of non-absorbed drug burden in the GI tract following overdose is unknown. Patients who present with clinical signs of toxicity may not undergo decontamination due to assumption that the drug has already been completely absorbed and because of limited scientific evidence of benefit for routine GI decontamination in poisoned patients.

OBJECTIVE

The goal of this study was to assess whether people who die of an oral overdose have unabsorbed drug present in the GI tract. The secondary goal was to analyze pharmacologic characteristics of retained drugs when present.

MATERIALS AND METHODS

Retrospective review of autopsy reports from 2008 to 2010, whose cause of death was determined as "intoxication" or "overdose, was performed at the Office of Chief Medical Examiner of the City of New York (OCME NYC)." Decedents of all ages were identified via electronic OCME database. Inclusion criteria were as follows: 1) cause of death "intoxication" or "overdose" noted by forensic autopsy, 2) ingestion of a solid drug formulation.

RESULTS

92 out of 1038 autopsies (9%) that met inclusion criteria had documentation of retained pill fragments, granules, paste, sludge, slurry, or whole pills in the GI tract. The most common drugs found were opioids and anticholinergics. Ninety-eight percent (98%) of the retained drugs were either modified-release preparations or drugs known to slow GI transit. Most decedents were dead on arrival; there were twelve in-hospital deaths and eleven patients died in the Emergency Department. Bupropion and venlafaxine were responsible for four deaths in those who received medical care. One person died in the ICU following bupropion ingestion.

DISCUSSION AND CONCLUSION

Overdose of an oral drug that either has modified-release properties or slows GI tract motility may result in substantial unabsorbed drug burden remaining in the GI tract.

A stepwise approach for the management of poisoning with extracorporeal treatments

The use of an extracorporeal treatment (ECTR) in a poisoned patient may be life-saving in a limited number of scenarios. The decision-processes surrounding the use of ECTR in poisoning is complex: most nephrologists are not trained to assess a poisoned patient while clinical toxicologists rarely prescribe ECTRs. Deciding on which ECTR is most appropriate for a poison requires a good understanding of the poison's physicochemical and pharmacokinetic properties. Further, a detailed understanding of the capabilities and limitations of the different ECTRs can be useful to select the most appropriate ECTR for a given clinical situation. This manuscript provides a stepwise approach to assess the usefulness of ECTRs in poisoning.

Applied clinical pharmacology and public health in rural Asia--preventing deaths from organophosphorus pesticide and yellow oleander poisoning

Self-poisoning with pesticides or plants is a major clinical problem in rural Asia, killing several hundred thousand people every year. Over the last 17 years, our clinical toxicology and pharmacology group has carried out clinical studies in the North Central Province of Sri Lanka to improve treatment and reduce deaths. Studies have looked at the effectiveness of anti-digoxin Fab in cardiac glycoside plant poisoning, multiple dose activated charcoal in all poisoning, and pralidoxime in moderate toxicity organophosphorus insecticide poisoning. More recently, using a Haddon matrix as a guide, we have started conducting public health and animal studies to find strategies that may work outside of the hospital. Based on the 2009 GSK Research in Clinical Pharmacology prize lecture, this review shows the evolution of the group's research from a clinical pharmacology approach to one that studies possible interventions at multiple levels, including the patient, the community and government legislation.

Cleistanthus collinus poisoning

Cleistanthus collinus, a toxic shrub, is used for deliberate self-harm in rural South India. MEDLINE (PUBMED) and Google were searched for published papers using the search/ MeSH terms “Cleistanthus collinus,” “Euphorbiaceae,” “Diphyllin,” “Cleistanthin A,” Cleistanthin B” and “Oduvanthalai.” Non-indexed journals and abstracts were searched by tracing citations in published papers. The toxic principles in the leaf include arylnaphthalene lignan lactones — Diphyllin and its glycoside derivatives Cleistanthin A and B. Toxin effect in animal models demonstrate neuromuscular blockade with muscle weakness, distal renal tubular acidosis (dRTA) and type 2 respiratory failure with conflicting evidence of cardiac involvement. Studies suggest a likely inhibition of thiol/thiol enzymes by the lignan-lactones, depletion of glutathione and ATPases in tissues. V-type H+ ATPase inhibition in the renal tubule has been demonstrated. Mortality occurs in up to 40% of C. collinus poisonings. Human toxicity results in renal tubular dysfunction, commonly dRTA, with resultant hypokalemia and normal anion gap metabolic acidosis. Aggressive management of these metabolic derangements is crucial. Acute respiratory distress syndrome (ARDS) is seen in severe cases. Cardiac rhythm abnormalities have been demonstrated in a number of clinical studies, though the role of temporary cardiac pacemakers in reducing mortality is uncertain. Consumption of decoctions of C. collinus leaves, hypokalemia, renal failure, severe metabolic acidosis, ARDS and cardiac arrhythmias occur in severe poisonings and predict mortality. Further study is essential to delineate mechanisms of organ injury and interventions, including antidotes, which will reduce mortality.

Enhanced poison elimination in critical care

Nephrologists and critical care physicians are commonly involved in the treatment of severely poisoned patients. Various techniques exist presently to enhance the elimination of poisons. Corporeal treatments occur inside of the body and include multiple-dose activated charcoal, resin binding, forced diuresis, and urinary pH alteration. Extracorporeal treatments include hemodialysis, hemoperfusion, peritoneal dialysis, continuous renal replacement therapy, exchange transfusion, and plasmapheresis. This review illustrates the potential indications and limitations in the application of these modalities as well as the pharmacological characteristics of poisons amenable to enhanced elimination.

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.

[A non-fatal Nerium oleander self-poisoning: case report and discussion]

Nerium oleander is potentially lethal plants after ingestion. We report a case of poisoning by these plants. Our patient complained of nausea, vomiting, and diarrhoea. He had bradycardia during first twelve hours. He was discharge after 3 days. All parts of these plants are toxic and contain a variety of cardiac glycosides including oleandrin. In most cases, clinical management of poisoning by N. oleander involves administration of activated charcoal and supportive care. Digoxin specific Fab fragments are an effective treatment.

Cutaneous absorption of Oleander: Fact or fiction

Cardiac conduction disorders following oral ingestion of Oleander plant materials were documented earlier. Transcutaneous absorption of yellow oleander (Thevetia peruviana) leaf extract applied over non intact skin (raw wound) resulting in reversible cardiac conduction disorder observed in four healthy males who were free from any other systemic or electrolyte or metabolic disorders or exposure to pesticide or toxins is reported for the first time. Their hematological, biochemical, clinical, and echocardiogram status were within normal limits and free of any abnormalities. One among the four, presented for weakness and breathlessness (class II). He had bradycardia with Mobitz II block and hypotension without any other demonstrable localizing signs. The other three were identified in the community and without any symptoms. However, their ECG revealed bradycardia with Mobitz I block in two and complete heart block in the other. All of the four recovered well without any untoward events. Hence, it is suggested that physicians and practitioners have to elicit history and route of administration of unconventional therapy, whenever they are confronted with clinical challenges and during medical emergencies before embarking final decision.

The use of mid-trial reviews for design modifications in small scale clinical studies

Many clinical studies such as those in the areas of toxicology, early phase clinical trials and bioequivalence studies use small samples due to the high cost of experimentation. These studies test hypotheses based on small samples. These small samples result in low power and therefore even if the alternative hypotheses may be true the chance of it being rejected is low. The sample size is determined in an ad-hoc way and no proper scientific approach is used. Sample size calculations for clinical studies are usually conducted to determine the total number of patients needed to satisfy a specified power requirement, and their validity is dependent on pre-trial knowledge of nuisance parameters and distributional and modelling assumptions. Another short coming is that often hypotheses are tested without checking the assumptions required by the test. This paper looks at design reviews in the context of small samples. It examines several design modifications done with a small internal pilot study. In the past similar techniques have been applied to large scale studies but its performance is yet to be established in small scale clinical studies thus the contribution of this paper is in justifying the validity of these techniques for small samples too. The methodology is illustrated on an uncontrolled observational toxicology study. In this paper simulations will be presented showing that the design modifications would not influence the type-I error rate and that these would be successful in preserving the power, and the implementation of the design review procedure will be described.

A review of the natural history, toxinology, diagnosis and clinical management of Nerium oleander (common oleander) and Thevetia peruviana (yellow oleander) poisoning

Nerium oleander (common oleander) and Thevetia peruviana (yellow oleander) are potentially lethal plants after ingestion. Poisoning by these plants is a common toxicological emergency in tropical and subtropical parts of the world and intentional self-harm using T. peruviana is prevalent in South Asian countries, especially India and Sri Lanka. All parts of these plants are toxic, and contain a variety of cardiac glycosides including neriifolin, thevetin A, thevetin B, and oleandrin. Ingestion of either oleander results in nausea, vomiting, abdominal pain, diarrhoea, dysrhythmias, and hyperkalemia. In most cases, clinical management of poisoning by either N. oleander or T. peruviana involves administration of activated charcoal and supportive care. Digoxin specific Fab fragments are an effective treatment of acute intoxication by either species. However, where limited economic resources restrict the use of such Fab fragments, treatment of severely poisoned patients is difficult. Data from case reports and clinical studies were reviewed to identify treatments supported by evidence for the management of poisoning by N. oleander and T. peruviana.

Fructose-1, 6-diphosphate (FDP) as a novel antidote for yellow oleander-induced cardiac toxicity: a randomized controlled double blind study

BACKGROUND

Cardiac toxicity due to ingestion of oleander plant seeds in Sri Lanka and some other South Asian countries is very common. At present symptomatic oleander seed poisoning carries a mortality of 10% in Sri Lanka and treatment of yellow oleander poisoning is limited to gastric decontamination and atropine administration. The only proven effective antidote is digoxin antibodies but these are not available for routine use because of the high cost. The main objective of this study is to investigate the effectiveness of a new and inexpensive antidote for patients with life threatening arrhythmias due oleander poisoning.

METHOD/DESIGN

We set up a randomised double blind clinical trial to assess the effectiveness of Fructose 1, 6 diphosphate (FDP) in acute yellow oleander poisoning patients admitted to the adult medical wards of a tertiary hospital in Sri Lanka. Patients will be initially resuscitated following the national guidelines and eligible patients will be randomised to receive either FDP or an equal amount of normal saline. The primary outcome measure for this study is the sustained reversion to sinus rhythm with a heart rate greater than 50/min within 2 hours of completion of FDP/placebo bolus. Secondary outcomes include death, reversal of hyperkalaemia on the 6, 12, 18 and 24 hour samples and maintenance of sinus rhythm on the holter monitor. Analysis will be on intention-to-treat.

DISCUSSION

This trial will provide information on the effectiveness of FDP in yellow oleander poisoning. If FDP is effective in cardiac glycoside toxicity, it would provide substantial benefit to the patients in rural Asia. The drug is inexpensive and thus could be made available at primary care hospitals if proven to be effective.

TRIAL REGISTRATION

Current Controlled trial ISRCTN71018309.

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.

Oleander intoxication in New World camelids: 12 cases (1995-2006)

OBJECTIVE

To characterize the clinical and clinicopathologic effects and evaluate outcome associated with oleander toxicosis in New World camelids.

DESIGN

Retrospective case series.

ANIMALS

11 llamas and 1 alpaca.

PROCEDURES

Medical records from a veterinary medical teaching hospital from January 1, 1995, to December 31, 2006, were reviewed. Records of all New World camelids that had detectable amounts of oleandrin in samples of serum, urine, or gastrointestinal fluid were included in the study. Descriptive statistics were used to evaluate the history, physical examination findings, clinicopathologic data, and outcome of affected camelids.

RESULTS

11 llamas and 1 alpaca met the inclusion criteria of the study. Either oleander plants were present where the camelids resided (n = 7) or oleander plant material was identified in the hay fed to the camelids (5). One llama was dead on arrival at the hospital, and another was euthanized upon admission because of financial concerns. Of the 10 treated camelids, 9 had evidence of acute renal failure, 7 had gastrointestinal signs, and 4 had cardiac dysrhythmias on initial evaluation. The overall mortality rate was 25%, but the mortality rate for the 10 camelids that were medically treated was 10%.

CONCLUSIONS AND CLINICAL RELEVANCE

In New World camelids, oleander intoxication was associated with a triad of clinical effects (ie, renal, gastrointestinal, and cardiovascular dysfunction). Oleander intoxication often represented a herd problem but carried a fair to good prognosis if treated promptly. Oleander toxicosis should be considered a differential diagnosis in sick camelids.

Management of yellow oleander poisoning

BACKGROUND

Poisoning due to deliberate self-harm with the seeds of yellow oleander (Thevetia peruviana) results in significant morbidity and mortality each year in South Asia. Yellow oleander seeds contain highly toxic cardiac glycosides including thevetins A and B and neriifolin. A wide variety of bradyarrhythmias and tachyarrhythmias occur following ingestion. Important epidemiological and clinical differences exist between poisoning due to yellow oleander and digoxin; yellow oleander poisoning is commonly seen in younger patients without preexisting illness or comorbidity. Assessment and initial management. Initial assessment and management is similar to other poisonings. No definite criteria are available for risk stratification. Continuous ECG monitoring for at least 24 h is necessary to detect arrhythmias; longer monitoring is appropriate in patients with severe poisoning. Supportive care. Correction of dehydration with normal saline is necessary, and antiemetics are used to control severe vomiting. Electrolytes. Hypokalemia worsens toxicity due to digitalis glycosides, and hyperkalemia is life-threatening. Both must be corrected. Hyperkalemia is due to extracellular shift of potassium rather than an increase in total body potassium and is best treated with insulin-dextrose infusion. Intravenous calcium increases the risk of cardiac arrhythmias and is not recommended in treating hyperkalemia. Oral or rectal administration of sodium polystyrene sulfonate resin may result in hypokalemia when used together with digoxin-specific antibody fragments. Unlike digoxin toxicity, serum magnesium concentrations are less likely to be affected in yellow oleander poisoning. The effect of magnesium concentrations on toxicity and outcome is not known. Hypomagnesaemia should be corrected as it can worsen cardiac glycoside toxicity. Gastric decontamination. The place of emesis induction and gastric lavage has not been investigated, although they are used in practice. Gastric decontamination by the use of single dose and multiple doses of activated charcoal has been evaluated in two randomized controlled trials, with contradictory results. Methodological differences (severity of poisoning in recruited patients, duration of treatment, compliance) between the two trials, together with differences in mortality rates in control groups, have led to much controversy. No firm recommendation for or against the use of multiple doses of activated charcoal can be made at present, and further studies are needed. Single-dose activated charcoal is probably beneficial. Activated charcoal is clearly safe. Arrhythmia management. Bradyarrhythmias are commonly managed with atropine, isoprenaline, and temporary cardiac pacing in severe cases, although without trial evidence of survival benefit, or adequate evaluation of possible risks. Accelerating the heart rate with atropine or beta-adrenergic agents theoretically increases the risk of tachyarrhythmias, and it has been claimed that atropine increases tachyarrhythmic deaths. Further studies are required. Tachyarrhythmias have a poor prognosis and are more difficult to treat. Lidocaine is the preferred antiarrhythmic; the role of intravenous magnesium is uncertain. Digoxin-specific antibody fragments. Digoxin-specific antibody fragments are effective in reverting life-threatening cardiac arrhythmias; prospective observational studies show a beneficial effect on mortality. High cost and lack of availability limit the widespread use of digoxin-specific antibody fragments in developing countries.

CONCLUSIONS

Digoxin-specific antibody fragments remain the only proven therapy for yellow oleander poisoning. Further studies are needed to determine the place of activated charcoal, the benefits or risks of atropine and isoprenaline, the place and choice of antiarrhythmics, and the effect of intravenous magnesium in yellow oleander poisoning.