2001 Annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System

The proper use of acetaminophen

Acetaminophen (N-acetyl-p-aminophenol, paracetamol [APAP])-induced acute liver failure is the most common cause of acute liver failure in adults. In children, APAP accounts for 25% of all cases of acute liver failure. The high mortality rate associated with this preventable condition makes it vital that paediatricians are aware of the potential adverse effects associated with this widely used drug. While APAP is generally considered to be safe when used as directed, its inclusion in multiple over-the-counter medications, as well as in prescription drugs, mandates that physicians promote and educate the general public about the proper use of acetaminophen in children.

Indicators for serious kidney complications associated with toxic exposures: an analysis of the National Poison Data System

CONTEXT

Over two million poisoning exposures are reported to U.S. poison control centers annually. A broad population-based survey of toxic exposures and the correlated patterns of reported kidney injury (acute or chronic) have not been systematically characterized.

OBJECTIVE

Our objective was to study the demographic and exposure patterns associated with indicators for serious kidney complications (ISKC), as defined by the variables in the NPDS.

MATERIALS AND METHODS

This was a retrospective, case-control study using the data elements available in the NPDS. We assessed data related to patient characteristics, substance exposure, and management. Cases and controls were derived from adult and pediatric exposures documented in NPDS (2001-2007) as having "renal effects." For substance-specific analyses, cases were restricted to those involving single substances or single entity pharmaceutical preparations. ISKC cases presented with one or more of the following NPDS codes: increased creatinine, and/or oliguria/anuria, and/or renal failure. Controls were subjects with "renal effects" but did not have increased creatinine, nor anuria/oliguria, nor renal failure. Univariate and multivariate logistic regression analyses identified factors associated with ISKC and determined the relationship between these factors.

RESULTS

From the approximate 16.8 million exposures reported to the NPDS within the study timeframe, there were 16,444 single substance exposures with renal effects of which 9,074 cases experienced ISKC (55.2%) compared to 7,370 controls without ISKC. Cases with ISKC tended to be males, adults, and reported to involve intentional exposures. Cases with ISKC had higher rates of reported hemodialysis/hemofiltration (27.7%; N = 2,517) and death (10.9%; N = 990) compared to controls, respectively, (2.1%; N = 155) and (0.8%; N = 60), p < 0.001. Substances considered a priori to be nephrotoxic were associated with a higher risk of ISKC.

DISCUSSION AND CONCLUSION

The NPDS provided insight into the subjects and types of exposures that associate with ISKC. Subjects with ISKC experienced higher rates of morbidity and mortality compared to subjects without ISKC. We identified subject characteristics and classes of compounds associated with ISKC. We hope that the hypotheses generated from this study of the NPDS will raise awareness of the possible risk factors and complications associated with ISKC.

Acute drug overdose: clinical profile, etiologic spectrum and determinants of duration of intensive medical treatment

OBJECTIVES

Acute drug overdosing is an important cause of organ dysfunction and metabolic derangements and the patients often require intensive care. This study aims to determine the clinical pattern of severe drug overdose as well as the factors influencing the duration of intensive care

METHODS

The clinical characteristics and course of consecutive adult patients admitted with a diagnosis of acute drug poisoning in the ICU of a tertiary hospital in Oman from January 2007 to December 2008 were reviewed retrospectively from the electronic case records.

RESULTS

Acute drug poisoning (n=29) constituted 3.9% of admissions to the ICU. Mean age was 29.38±7.9 years. They were brought in by their relatives (72%) or the state services (24%). Accidental poisoning was noted in 21 patients (72%) and suicidal overdosing in 6 (21%). The commonest drug was an opioid (65.5%). Glasgow Coma Scale score of ≤8 was recorded in 18 (62.1%). Sixty two percent of patients required mechanical ventilation. The prominent complications were hypotension in 9 (31%), pulmonary in 19 (65.5%), hepatic in 18 (62.1%) and renal in 12 (41.4%) patients. The major electrolytes abnormalities were low bicarbonate in 11 (37.9%), hyponatremia in 5 (17.2%) and hypokalemia in 4 (13.8%). Patients stayed in the ICU for 1 to 20 days (median-2 days). Factors associated with a longer ICU stay included hypotension upon arrival (p=0.048) and the need for mechanical ventilation on the first (p=0.001) and second (p=0.001) days of hospitalization. There was no mortality.

CONCLUSION

Early and prompt intensive medical therapy in acute drug poisoning can favorably influence the outcome. In addition, the presence of hypotension and requirement of mechanical ventilation on the first two days of hospitalization were responsible for prolonged ICU stay.

Analysis of plasma nucleotides in rat by micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry

RATIONALE

The aim of this study was to establish a simultaneous quantitative analysis method of nine endogenous nucleotides in rat plasma using micellar electrokinetic capillary chromatography/electrospray ionization mass spectrometry (MEKC/ESI-MS).

METHODS

To select the optimum conditions for separation of the nucleotides, various pH, concentrations of running buffers and surfactants were tested. Ammonium acetate (20 mM) containing the surfactant dodecyltrimethylammonium bromide (2 mM, pH 3.5) was selected as the micellar running buffer. The plasma samples were prepared by precipitating the proteins with 2 mM EDTA in 60% ethanol. The samples were analyzed using capillary electrophoresis (CE)/MS and selected ion monitoring (SIM) mode with positive ionization. CE was performed using a silica capillary column in reversed polarity mode.

RESULTS

The limits of detection (LODs) and limits of quantification (LOQs) of the nucleotides ranged from 0.05-5 and 2.0-20 μM, respectively. The calibration curves were linear (R(2) >0.99) for all analytes, and the accuracy and precision were within ±15%. The developed method was applied to the analysis of nucleotides in rat plasma that was collected after oral administration of acetaminophen (1000 mg/kg/day) to evaluate the changes in plasma nucleotide levels under hepatotoxic conditions.

CONCLUSIONS

Decreased level of GTP and increased level of cytosine nucleotides were found to be associated with liver toxicity, which led to the conclusion that liver toxicity is closely related to changes in nucleotide levels in plasma.

Exotic venomous snakebite drill

BACKGROUND

There were 900 exotic venomous snakebites reported from 2000 to 2009. The Association of Zoos and Aquariums' recommends institutions housing venomous reptiles have protocols for appropriate and timely transport of envenomed individuals to hospitals. The study objective was to evaluate functional aspects and potential problems of our emergency operation procedure designed for handling the response to an exotic venomous snakebite during implementation via a simulated drill. The emergency operation procedure consists of two protocols, the protocol for zoo personnel and exotic snakebite protocol for hospital personnel.

METHODS

Before the exercise the poison center (PC), zoo, Emergency Medical Services (EMS), receiving hospital emergency department (ED), and pharmacy were contacted. The emergency operation procedure was reviewed to determine areas of deficiency. A checklist of all required actions for each participating institution was created for use during the exercise. The exercise was divided into four phases: zoo, EMS, PC, and ED. Each phase was evaluated by an independent observer.

RESULTS

Review of the emergency operation procedure revealed sufficient and easy to follow information for zoo personnel. However, the exotic snakebite protocol for hospital personnel lacked details regarding signs and symptoms expected from each exotic venomous species in the zoo; and indications, dosing, and instructions on reconstitution for each of the antivenom carried by the zoo. Zoo, EMS, ED, and PC personnel completed 95%, 90%, 83%, and 25% of the required tasks, respectively. The PC encountered problems communicating the exotic snakebite protocol for hospital personnel to the ED due to phone and fax equipment failures. Creative solutions to the PC system issues were not identified in a timely manner. Despite the shortcomings, the time from simulated envenomation to antivenom (AV) administration was under an hour.

CONCLUSIONS

This drill identified several issues leading to revision of our exotic snakebite protocol for hospital personnel. We also identified suboptimal PC response in the application of the emergency operation procedure. We encourage every poison center in cooperation with local zoos to perform a similar exercise.

Anaphylaxis with Latrodectus antivenin resulting in cardiac arrest

Latrodectus mactans antivenin is a safe and effective therapy for severe black widow spider envenomations when given to most patients. We report a case of a 37-year-old male with a history of asthma that was given L. mactans antivenin for symptoms related to a black widow envenomation and developed a severe anaphylactic reaction resulting in cardiac arrest. When traditional therapies failed, the patient was given methylene blue for anaphylactic shock resulting in a 30-h period of hemodynamic stability. Despite initial resuscitation, the patient ultimately died 40 h after presentation. Under the right circumstances, L. mactans antivenin remains a safe and effective therapy for severe black widow envenomations. However, anaphylaxis is a risk for those receiving this therapy, even when the antivenin is diluted and given as an infusion. We report the first death related to diluted L. mactans antivenin given as an infusion.

Frequency and outcomes of accidental ingestion of tobacco products in young children

This review assesses published literature related to frequency and outcomes associated with accidental ingestion of tobacco and pharmaceutical nicotine products among young children. Twenty-seven years of annual reports by American Association of Poison Control Centers (AAPCC) were analyzed for occurrence and outcomes associated with accidental ingestion events involving tobacco and pharmaceutical nicotine products among young children. Over a 27-year period, and of >50 million contacts for all categories combined, 217,340 contacts involving ingestion of tobacco products were reported. Approximately 89% involved children <6 years old. One fatality was reported, however the co-ingestion of both cigarettes and diazepam complicates an assessment of a contributory role of tobacco. The rate of major, non-fatal, outcomes was <0.1%. Data from AAPCC reports and other sources indicate the frequency of accidental poisoning events is relatively low for tobacco products compared with other products such as drugs, dietary supplements, cleaning products, and personal care products. These findings, along with those for pharmaceutical nicotine products, are consistent with published case reports and reviews, indicating that the frequency and severity of outcomes associated with accidental ingestion of tobacco products by young children appear to be relatively low. However, adults should keep tobacco products out of the reach of children.

Pediatric foreign body aspiration: How much does our community know?

Aims:

Foreign body aspiration (FBA) is one of the main causes of accidental death in childhood. This study was designed to evaluate the level of awareness of FBA and its resultant dangers in the community.

Materials and Methods:

Sixty-three primary caregivers were interviewed about their awareness of FBA, its attendant dangers, preventive measures taken, and how will they take care of a child in the event of a FBA according to an agreed protocol.

Results:

Awareness levels about FBA were abysmally low in the population that was studied. Twenty-five percentage of the study population had not heard about this condition, and 46% could not recognize a FBA if it happened. Also, 76% of the study group did not know about the attendant dangers of this condition.

Conclusions:

There is a dire need to spread awareness about both prevention and treatment of this morbid condition. Health care professionals need to increase their efforts to spread more knowledge in the community about FBA.

Suicide by gabapentin overdose

Gabapentin is an antiepileptic drug that is prescribed for both FDA-approved and multiple off-label conditions, and has a relatively safe side-effect profile. Rare cases of overdose-related adverse effects have been reported in the literature. Described herein are the circumstances and autopsy findings of a 62-year-old woman with a history of depression, whose death was caused by intentional ingestion of excess gabapentin. The postmortem peripheral blood gabapentin concentration as determined by high-performance liquid chromatography/tandem mass spectroscopy was 88 μg/mL. Previously reported cases of individuals surviving gabapentin overdoses are discussed and compared with this case. Based on a review of the available literature, this appears to be the first published report of a death due solely to gabapentin toxicity.

[Necrotic arachnidism in the south of France: two clinical cases of loxoscelism]

BACKGROUND

loxosceles spiders are found throughout the world and are responsible for numerous cases of envenomation in America and Southern Europe. We describe, to our knowledge for the first time in France, two clinical cases of cutaneous loxoscelism.

CASE REPORT

two cases of skin necrosis arising after supposed spider bites were grouped together because of their similar clinical presentation: an initial painless bite and rapid development of an inflammatory and painful cutaneous lesion with a central hemorrhagic bulla surrounded by a perimeter of blanched skin (the "red, white, and blue" sign). The outcome in both cases was deep skin necrosis and chronic ulceration requiring surgical treatment.

DISCUSSION

loxoscelism can result in dermonecrosis. Although our cases were not documented by capture of the spider, the diagnosis of cutaneous loxoscelism was supported by the characteristic appearance of the lesion, a typical clinical course, elimination of differential diagnoses, and the confirmed presence of Loxosceles rufescens in the region.

CONCLUSION

loxoscelism can occur in the south of France and although rare, must be considered in this region as a possible cause of skin necrosis.

Unified treatment algorithm for the management of crotaline snakebite in the United States: results of an evidence-informed consensus workshop

BACKGROUND

Envenomation by crotaline snakes (rattlesnake, cottonmouth, copperhead) is a complex, potentially lethal condition affecting thousands of people in the United States each year. Treatment of crotaline envenomation is not standardized, and significant variation in practice exists.

METHODS

A geographically diverse panel of experts was convened for the purpose of deriving an evidence-informed unified treatment algorithm. Research staff analyzed the extant medical literature and performed targeted analyses of existing databases to inform specific clinical decisions. A trained external facilitator used modified Delphi and structured consensus methodology to achieve consensus on the final treatment algorithm.

RESULTS

A unified treatment algorithm was produced and endorsed by all nine expert panel members. This algorithm provides guidance about clinical and laboratory observations, indications for and dosing of antivenom, adjunctive therapies, post-stabilization care, and management of complications from envenomation and therapy.

CONCLUSIONS

Clinical manifestations and ideal treatment of crotaline snakebite differ greatly, and can result in severe complications. Using a modified Delphi method, we provide evidence-informed treatment guidelines in an attempt to reduce variation in care and possibly improve clinical outcomes.

A localizing circumferential compression device delayed death after artificial eastern diamondback rattlesnake envenomation to the torso of an animal model in a pilot study

Nearly all prior studies to delay onset of systemic toxicity and death after snake bite use a model of distal extremity envenomation. In the first of a series of planned studies using snake venoms with different toxicity profiles, the application of a novel device in a new model of torso envenomation in the setting of Eastern Coral Snake (Micrurus fulvius) venom (a potent neurotoxin) envenomation showed promise by delaying systemic intoxication. In this pilot study, we investigated this novel localizing circumferential compression (LoCC) device's ability to delay onset of life threatening systemic toxicity after Eastern Diamondback Rattlesnake (Crotalus adamanteus) envenomation, a potent hemotoxic and myotoxic venom. With university approval, four juvenile female pigs (22-25 kg) were anesthetized, sedated, and intubated but not paralyzed to allow for spontaneous respirations. Each animal was injected subcutaneously with 50 mg of C. adamanteus venom in identical preselected areas of the trunk. After 1 min, two treatment animals had the LoCC device applied; two control animals had no intervention. Vital signs were recorded every 10 min for the first 2 h and every 30 min thereafter. Endpoints included cardiovascular collapse (fatal arrhythmia, loss of mean arterial pressure, or pulse) or respiratory arrest (<3 breaths/min, saturation < 80%) or survival to 7 h. The pigs in the treatment group reached an endpoint at an average time of 355 (+/-65) min compared with control 32 (+/-3.5) min (p < 0.04). In this pilot study, the LoCC device significantly delayed onset of systemic symptoms and death after torso envenomation with Eastern Diamondback Rattlesnake venom in this model.

A localizing circumferential compression device increases survival after coral snake envenomation to the torso of an animal model

BACKGROUND

Pressure immobilization bandages have been shown to delay onset of systemic toxicity after Eastern coral snake (Micrurus fulvius) envenomation to the distal extremity.

OBJECTIVES

To assess the efficacy of a novel compression device in delaying onset of systemic toxicity after truncal envenomations with Eastern coral snake (Micrurus fulvius) venom in a porcine model.

METHODS

With University approval, nine juvenile pigs (11 kg to 22 kg) were sedated, anesthetized, and intubated but not paralyzed to ensure continuous spontaneous respirations in a university animal laboratory. Each animal was injected subcutaneously with 10 mg of M. fulvius venom in a pre-selected area of the trunk. After 1 min, six animals had the application of a novel, localizing circumferential compression (LoCC) device applied to the bite site (treatment group) and three animals had no treatment (control group). The device was composed of a rigid polymer clay form molded into a hollow fusiform shape with an internal dimension of 8 × 5 × 3 cm and an elastic belt wrapped around the animal securing the device in place. Vital signs were recorded at 30-min intervals. End points included a respiratory rate below 3 breaths/min, oxygen saturation < 80%, or survival to 8 h. Survival to 8 h was analyzed using Fisher's exact test, with p < 0.05 indicating significance. Survival analysis was performed using the Mantel-Cox test to assess time to death with outcomes represented in a Kaplan-Meier Cumulative survival plot.

RESULTS

Five of the six pigs in the treatment group survived 8 h (293-480 min). None of the control pigs survived to 8 h (Fisher's exact p = 0.04), with mean time of respiratory failure 322 min (272-382 min). Survival analysis showed a significant delay in time to event in the treatment group compared to the control group (p = 0.04).

CONCLUSIONS

The LoCC device used in this study delayed the onset of systemic toxicity and significantly increased survival time after artificial truncal envenomation by Eastern coral snake venom.

Compliance with atypical antipsychotic triage guidelines by Texas poison centers

Triage guidelines for poison center management of atypical antipsychotic ingestions were published in December 2007. This investigation determined whether Texas poison centers already complied with a simplified version of these guidelines. All acute aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone ingestions reported to Texas poison centers during 2000-2007 were identified. Exclusion criteria were the presence of coingestants, patient already at or en route to a health-care facility when the poison center was contacted, and chronic ingestion. Each case was evaluated whether it was managed in compliance with the simplified triage guidelines and the compliance rate calculated. For 2,611 total cases, the compliance rate was 64.1%. The rate was 71.7% for aripiprazole, 43.6% for clozapine, 71.6% for olanzapine, 60.8% for quetiapine, 65.5% for risperidone, and 59.0% for ziprasidone. The majority of acute atypical antipsychotic ingestions reported to Texas poison centers were managed according to a simplified version of recommended triage algorithm.

Effect of levosimendan in experimental verapamil-induced myocardial depression

Background

Calcium antagonist overdose can cause severe deterioration of hemodynamics unresponsible to treatment with beta adrenergic inotropes. The aim of the study was to evaluate in an experimental model the effects of levosimendan during severe calcium antagonist intoxication.

Methods

Twelve landrace-pigs were intoxicated with intravenous verapamil at escalating infusion rates. The infusion containing 2.5 mg/ml verapamil was used aiming to a reduction of cardiac output by 40% from the baseline value. Intoxicated pigs were randomized into two groups: control (saline) and levosimendan (intravenous bolus). Inotropic effect was measured as a change in a maximum of the positive slope of the left ventricular pressure (LV dP/dt). The survival and hemodynamics of the animals were followed for 120 min after the targeted reduction of cardiac output.

Results

In the control group, five out of six pigs died during the experiment. In the levosimendan group, one pig died before completion of the experiment (p = 0.04). In the levosimendan group a change in LV dP/dt was positive in four out of six pigs compared to one out of six pigs in the control group (p = ns).

Conclusions

In this experimental model, the use of levosimendan was associated with improved survival.

Mechanisms of acetaminophen-induced liver necrosis

Although considered safe at therapeutic doses, at higher doses, acetaminophen produces a centrilobular hepatic necrosis that can be fatal. Acetaminophen poisoning accounts for approximately one-half of all cases of acute liver failure in the United States and Great Britain today. The mechanism occurs by a complex sequence of events. These events include: (1) CYP metabolism to a reactive metabolite which depletes glutathione and covalently binds to proteins; (2) loss of glutathione with an increased formation of reactive oxygen and nitrogen species in hepatocytes undergoing necrotic changes; (3) increased oxidative stress, associated with alterations in calcium homeostasis and initiation of signal transduction responses, causing mitochondrial permeability transition; (4) mitochondrial permeability transition occurring with additional oxidative stress, loss of mitochondrial membrane potential, and loss of the ability of the mitochondria to synthesize ATP; and (5) loss of ATP which leads to necrosis. Associated with these essential events there appear to be a number of inflammatory mediators such as certain cytokines and chemokines that can modify the toxicity. Some have been shown to alter oxidative stress, but the relationship of these modulators to other critical mechanistic events has not been well delineated. In addition, existing data support the involvement of cytokines, chemokines, and growth factors in the initiation of regenerative processes leading to the reestablishment of hepatic structure and function.

Efficacy of North American crotalid antivenom against the African viper Bitis gabonica (Gaboon viper)

Envenomations by exotic snakes occur from zoological collections and private individual collectors. Antivenoms to these snakes may not be readily available. The objective of this study is to determine the efficacy of North American crotalid antivenin in treating mice envenomated with venom of the African viper Bitis gabonica (Gaboon viper). The subjects of the study were Swiss Webster mice weighing approximately 30 g. The study was conducted in the University research laboratory. B. gabonica venom was obtained from Venom Supplies Pty Ltd (Tanunda, South Australia) and reconstituted in sterile water. North American Crotalid Fab2 antivenin (Anavyp, Instituto Bioclon, Mexico) was donated by the manufacturer. The experimental groups were: Group I received two times an intraperitoneal LD(50) dose of venom, 2.58 mg/kg. Group II received the same dose after incubation for 1 h with 10 mg of antivenin. Time to onset of toxicity defined as respiratory rate <10/min or absence of response to prodding. t test and Chi square with p < 0.05 considered significant. Time to onset of toxicity was 7.040 +/- 4.334 h in group I, and 20.665 +/- 2.074 in group II (p = 0.0064, 95% confidence interval of difference of means -22.694 to -4.556). Antivenin was efficacious to statistical significance at 4, 8, 12, and 16 h (p values of 0.062, 0.0067, 0.0067, and 0.0253, respectively). Improvement at 20 and 24 h (p values of 0.0673 and 0.0673, respectively) did not achieve statistical significance. North American Crotalid antivenin (Anavyp, Instituto Bioclon, Mexico) demonstrated efficacy in increasing time to onset of distress in mice poisoned with B. gabonica (Gaboon viper) venom. Based on this result, treatment of humans envenomated with B. gabonica with North American Croatlid antivenin could be considered for severe envenomations if specific B. gabonica antivenin is unavailable.

A prospective observational study of the clinical toxicology of glyphosate-containing herbicides in adults with acute self-poisoning

CONTEXT

The case fatality from acute poisoning with glyphosate-containing herbicides is approximately 7.7% from the available studies but these have major limitations. Large prospective studies of patients with self-poisoning from known formulations who present to primary or secondary hospitals are needed to better describe the outcome from acute poisoning with glyphosate-containing herbicides. Furthermore, the clinical utility of the glyphosate plasma concentration for predicting clinical outcomes and guiding treatment has not been determined.

OBJECTIVE

To describe the clinical outcomes, dose-response, and glyphosate kinetics following self-poisoning with glyphosate-containing herbicides.

METHODS

This prospective observational case series was conducted in two hospitals in Sri Lanka between 2002 and 2007. We included patients with a history of acute poisoning. Clinical observations were recorded until discharge or death. During a specified time period, we collected admission (n = 216, including five deaths) and serial (n = 26) blood samples in patients. Severity of poisoning was graded using simple clinical criteria.

RESULTS

Six hundred one patients were identified; the majority ingested a concentrated formulation (36%, w/v glyphosate). Twenty-seven percent were asymptomatic, 63.7% had minor poisoning, and 5.5% of patients had moderate to severe poisoning. There were 19 deaths (case fatality 3.2%) with a median time to death of 20 h. Gastrointestinal symptoms, respiratory distress, hypotension, altered level of consciousness, and oliguria were observed in fatal cases. Death was strongly associated with greater age, larger ingestions, and high plasma glyphosate concentrations on admission (>734 microg/mL). The apparent elimination half-life of glyphosate was 3.1 h (95% CI = 2.7-3.6 h).

CONCLUSIONS

Despite treatment in rural hospitals with limited resources, the mortality was 3.2%, which is lower than that reported in previous case series. More research is required to define the mechanism of toxicity, better predict the small group at risk of death, and find effective treatments.

The FDA Acetaminophen Advisory Committee Meeting - what is the future of acetaminophen in the United States? The perspective of a committee member

BACKGROUND

Unintentional acetaminophen toxicity is a common problem throughout the world but particularly in the more developed countries. To deal with the problem, several countries have attempted to decrease the risk of acetaminophen overdose by reducing package sizes. The U.S. Food and Drug Administration (FDA) convened a joint meeting recently of three Advisory Committees to consider the issue of unintentional acetaminophen-related toxicity and to explore strategies to address the problem.

PROPOSALS AND RECOMMENDATIONS

Three strategies addressed the issue of dose reduction as a way to decrease morbidity and mortality. The FDA proposed a decrease in the maximum daily dose from 4,000 to 3,250 mg, reducing the maximum individual dose from 1,000 to 650 mg and relegating 500 mg tablets to prescription status. The Committees voted in favor of each of those initiatives. Restricting the number of doses that could be purchased by regulating package sizes, as has been done in some European countries, was proposed, but rejected by the Committees. Proposals also addressed the elimination of nonprescription and prescription acetaminophen combination products (e.g., multi-symptom cold relief combinations and acetaminophen/opioid combinations) as a strategy to decrease unintentional poisoning when individuals unknowingly take different products, all of which contain acetaminophen. The Committees rejected the proposal to eliminate the nonprescription combinations but recommended the elimination of prescription combination products. Currently, liquid acetaminophen is available in the United States in three different concentrations. To reduce the confusion associated with the variance in concentrations the Committees voted to have a single concentration for all acetaminophen liquid products. Finally, the Committees voted, almost unanimously, to encourage the FDA to place a boxed warning in the product information to create awareness among prescribers and pharmacists about acetaminophen toxicity and to educate their patients accordingly.

CONCLUSIONS

Many of the recommendations were not evidence-based but instead have an anecdotal basis. However, the Committees are advisory to the FDA, their recommendations are not binding and it remains to be seen which of the recommendations will be implemented.

Risk assessment of severe tricyclic antidepressant overdose

Prognostic factors for severe complications in tricyclic antidepressant (TCA) overdose remain unclear. We therefore evaluated the value of clinical characteristics and electrocardiograph (ECG) parameters to predict serious events (seizures, arrhythmia, death) in severe TCA overdose of 100 patients using logistic regression models for risk assessment. The overall fatality rate was 6%, arrhythmia occurred in 21% and 31% of the patients developed seizures. Using an univariable logistic regression model, the maximal QRS interval (OR 1.22; 95% CI 1.06-1.41; p = .005), the time lag between ingestion and occurrence of first symptoms of overdose (OR 1.13; 95% CI 0.99-1.29; p = .072) and the age (OR 0.73; 95% CI 0.55-0.98; p = .038) were determined as the solely predictive parameters. In the multivariable logistic regression model, the QRS interval could not be established as independent predictor, however, the terminal 40-ms frontal plane QRS vector (T40) reached statistical significance regarding prediction of serious events (odds ration [OR] 1.70; 95% confidence interval [CI] 1.02-2.84; p = .041), along with age and time lag between ingestion and onset of symptoms of overdose with a sensitivity and specificity of 71% and 70%, respectively. Evaluation of both clinical characteristics and ECG-parameters in the early stage of TCA overdose may help to identify those patients who urgently need further aggressive medical observation and management.

Illicit gamma-hydroxybutyrate (GHB) and pharmaceutical sodium oxybate (Xyrem): differences in characteristics and misuse

There are distinct differences in the accessibility, purity, dosing, and misuse associated with illicit gamma-hydroxybutyrate (GHB) compared to pharmaceutical sodium oxybate. Gamma-hydroxybutyrate sodium and sodium oxybate are the chemical and drug names, respectively, for the pharmaceutical product Xyrem (sodium oxybate) oral solution. However, the acronym GHB is also used to refer to illicit formulations that are used for non-medical purposes. This review highlights important differences between illicit GHB and sodium oxybate with regard to their relative abuse liability, which includes the likelihood and consequences of abuse. Data are summarized from the scientific literature; from national surveillance systems in the U.S., Europe, and Australia (for illicit GHB); and from clinical trials and post-marketing surveillance with sodium oxybate (Xyrem). In the U.S., the prevalence of illicit GHB use, abuse, intoxication, and overdose has declined from 2000, the year that GHB was scheduled, to the present and is lower than that of most other licit and illicit drugs. Abuse and misuse of the pharmaceutical product, sodium oxybate, has been rare over the 5 years since its introduction to the market, which is likely due in part to the risk management program associated with this product. Differences in the accessibility, purity, dosing, and misuse of illicit GHB and sodium oxybate suggest that risks associated with illicit GHB are greater than those associated with the pharmaceutical product sodium oxybate.

Cardiovascular medication errors in children

OBJECTIVES

We sought to describe pediatric cardiovascular medication errors and to determine patients and medications with more-frequently reported and/or more-harmful errors.

METHODS

We analyzed cardiovascular medication error reports from 2003-2004 for patients <18 years of age, from the US Pharmacopeia MEDMARX database. Reports were stratified according to harm score (A, near miss; B-D, error, no harm; E-I, harmful error). Proportions of harmful reports were determined according to drug class and age group. "High-risk" drugs were defined as antiarrhythmics, antihypertensives, digoxin, and calcium channel blockers.

RESULTS

A total of 147 facilities submitted 821 reports with community hospitals predominating (70%). Mean patient age was 4 years (median: 0.9 years). The most common error locations were NICUs, general care units, PICUs, pediatric units, and inpatient pharmacies. Drug administration, particularly improper dosing, was implicated most commonly. Severity analysis showed 5% "near misses," 91% errors without harm, and 4% harmful errors, with no reported fatalities. A total of 893 medications were cited in 821 reports. Diuretics were cited most frequently, followed by antihypertensives, angiotensin inhibitors, beta-adrenergic receptor blockers, digoxin, and calcium channel blockers. Calcium channel blockers, phosphodiesterase inhibitors, antiarrhythmics, and digoxin had the largest proportions of harmful events, although the values were not statistically significantly different from those for other drug classes. Infants <1 year of age accounted for 50% of reports. Proportions of harmful events did not differ according to age.

CONCLUSIONS

Infants <1 year of age were most frequently reported in cardiovascular medication errors reaching inpatients, in a national, voluntary, error-reporting database. Proportions of harmful errors were not significantly different by age or cardiovascular medication. Most errors were related to medication administration, largely due to improper dosing.

Crotaline Fab antivenom appears to be effective in cases of severe North American pit viper envenomation: an integrative review

Background

In 2000, the United States Food and Drug Administration approved Crotalidae Polyvalent Immune Fab (Ovine) (hereafter, FabAV), "for the management of patients with minimal to moderate North American Crotalid envenomation." Because whole-IgG pit viper antivenom is no longer available in the United States, FabAV is currently the only specific treatment option available to United States clinicians treating snakebite victims of any severity. No clinical trial data are available concerning the effectiveness of FabAV for treatment of severe snakebite, but several published articles describe its use in this setting.

Methods

We performed a comprehensive review of the English-language medical literature to identify all publications (1996 to July, 2008) containing data about the administration of FabAV. Two trained reviewers separately extracted case-level data concerning the administration of FabAV to patients with severe envenomation by North American crotaline snakes to a standardized form. Descriptive statistics were used. In addition, we hand-searched the US National Poison Data System reports for the years 2000–2006 to identify and describe any reports of death that occurred after FabAV administration.

Results

The literature review found 147 unique publications regarding FabAV. Twenty-four evaluable cases of severe human envenomation treated with FabAV were identified in 19 publications. Seven cases were described in five cohort studies, and 17 cases were described in 14 single patient case reports or non-cohort case series. Sixty-five specific severe venom effects were reported in these 24 patients, of which 50 effects (77%) improved or resolved after FabAV therapy. Initial control of all severe venom effects was achieved in 12 patients (50%). The rate at which initial control was achieved was significantly higher among patients reported in the cohort series than in the case series and non-cohort reports (100% vs. 29%, P = 0.005). The median dose of FabAV used to obtain initial control was 6 vials (range: 4 – 18 vials). Nine patients had severe venom effects that persisted despite FabAV therapy. Recurrent and/or delayed-onset severe defibrination syndrome occurred in 12 patients, most of whom did not receive recommended maintenance FabAV dosing. No patient developed systemic bleeding.

Conclusion

In this structured literature review, FabAV appears to be effective in the management of severe crotaline snake envenomation. Incomplete response to therapy, recurrence of venom effects, and delayed-onset venom effects were reported in case reports, but not reported in cohort studies.

Homicidal poisoning deaths in the United States 1999-2005

OBJECTIVES

Homicidal poisoning is an intriguing but poorly described phenomenon. This study describes homicidal poisoning deaths in the United States during 1999-2005.

METHODS

A trend analysis of homicidal poisoning death was performed using Vital Statistics data. The National Mortality Statistics database was queried using "homicide" as injury intent and "poisoning" as mechanism for the years 1999-2005. Counts and rates were obtained for subgrouping by using demographic data and ICD-10 codes. Chi-square analysis calculated subgroup odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

A total of 523 homicidal poisoning deaths were identified. The overall rate for the period was 0.26/million/year. Males were significantly (OR 1.34, CI 1.13-1.59) more likely to victims than females. Death was more likely at extremes of age. Rates were 2.05/million (OR 8.72, CI 6.63-11.49) in children <1 year and 0.56/million (OR 2.20, CI 1.38-3.52) at ages >or=85 years. Rates also varied by race and were more common among Blacks (0.43/million; OR 1.83, CI 1.47-2.26). The greatest rate was observed in Black infants (5.3/million; OR 21.34, CI 14.17-32.15). ICD-10 codes indicated that medications were the most common poison. Rates were significantly higher in the West and lower in the Northeast.

CONCLUSION

The overall homicidal poisoning death rate was low between 1999 and 2005. The most common type of poison used was medications. Substantially higher rates were observed in vulnerable populations at extremes of age, particularly infants, and among Blacks. This challenges common notions of the victims of homicidal poisoning and the underlying motivation of their poisoners.

The state of dietary supplement adverse event reporting in the United States

PURPOSE

The Dietary Supplements Information Expert Committee (DSI-EC; the Committee) of the United States Pharmacopeial Convention (USP) reviews safety profiles of dietary supplements before development of USP-National Formulary (USP-NF) quality monographs. Because the veracity of dietary supplement adverse event reports (DS AERs) directly affects DSI-EC safety reviews, the Committee reviewed the current status of DS AER reporting in the US.

METHODS

DSI-EC reviewed PubMed searches, information from the US Food and Drug Administration's (FDA) MedWatch program, the Toxic Exposure Surveillance System (TESS) of the American Association of Poison Control Centers (AAPCC), and reports from US and other agencies. DSI-EC analyzed this information to identify key factors that affect the quality of DS AERs.

RESULTS

The overall incidence of DS AERs appears generally to be low. However, the primary reporting portal (FDA MedWatch) receives fewer AERs than do poison control centers (PCCs), and limited coordination exists among national and international surveillance programs for evaluating signals that may indicate potential public health risks. Both inadequate and poor-quality reporting of DS AERs are major limitations of DS safety monitoring in the US.

CONCLUSIONS

Based on its assessments, the Committee advances recommendations to improve the quality of reporting, monitoring, and assessing DS AERs. These include (1) enhanced data collection approaches, (2) improved coordination of AER surveillance programs, (3) strengthening of educational programs for public and health care sectors, and (4) conduct of research concerning the safety of DS. If taken, these approaches are expected to improve the health and well-being of DS users.

Therapeutic errors among children in the community setting: nature, causes and outcomes

AIM

This study aimed to determine the epidemiology of therapeutic errors among children in the community setting.

METHODS

This was a prospective, observational study of 491 consecutive cases reported to the Victorian Poisons Information Centre, between January 2006 and March 2007. A total of 450 (91.7%) parents/carers were followed up by telephone approximately 48 h after the initial call. The main outcome measures were the nature, causes and outcomes of the errors and actions taken or recommendations given to avoid future errors.

RESULTS

The majority of children (334, 68.0%, 95% confidence interval (CI) 63.7, 72.1) were aged <or=3 years. Incorrect and double dosage accounted for 279 (56.8%, 95% CI 52.3, 61.2) and 128 (26.1%, 95% CI 22.3, 30.2) cases, respectively. Almost all errors occurred in the home (98.2%) and involved a single medication (98.8%) and the oral route (98.4%). Close family members were responsible in 408 (83.1%, 95% CI 79.4, 86.2) cases. Analgesics and cough and cold preparations were taken in error in 259 (52.0%) cases. Human (rushing, distraction, carelessness) and communication factors were reported to be causal factors in 337 (38.4%, 95% CI 35.2, 41.8) and 111 (12.7%, 95% CI 10.6, 15.1) cases, respectively. In almost all cases (474, 96.5%, 95% CI 94.4, 97.9), the caller was advised to observe the child at home, and no child experienced significant morbidity. Preventive strategies included attention to administration care and routine, communication, medication storage, administration devices, packaging and labelling issues.

CONCLUSION

Very young children are at particular risk, especially from single, over-the-counter medication dosing errors, made at home by family members.

Brimonidine tartrate poisoning in children: frequency, trends, and use of naloxone as an antidote

BACKGROUND

Brimonidine tartrate, a centrally acting selective alpha-2 adrenergic agonist with a toxicity that is often compared with that of clonidine, is used as eye drops to lower intraocular pressure in glaucoma. We investigated characteristics of childhood exposures to brimonidine-containing products.

METHODS

All brimonidine exposures in children 0 to 5 years of age between 1997 and 2005 were retrieved from the American Association of Poison Control Centers' Toxic Exposure Surveillance System database and the US Food and Drug Administration's Medwatch Adverse Events Reporting System. The design of the study was retrospective, and the main outcome measures were frequency of exposures over time, reason, symptoms/signs of toxicity, dose, management site, treatment, and outcome.

RESULTS

There were 413 brimonidine reports in the Toxic Exposure Surveillance System and 340 in the Adverse Events Reporting System during the 9 years under study, of which 185 Toxic Exposure Surveillance System reports involved children < or =5 years of age versus 15 cases in the Adverse Events Reporting System. There were no deaths. The peak age of poisoning in the Toxic Exposure Surveillance System pediatric cases was 2 years of age, and circumstances were unintentional poisoning in 176 cases, usually by ingestion (84.3%). Common symptoms in 176 children included drowsiness (40.9%), ataxia (4.5%), pallor (4.5%), irritability (4.0%), hypotension (4.0%), bradycardia (4.0%), miosis (3.4%), and respiratory depression (3.4%). Of the 176 unintentional pediatric poisonings, 73 children were observed at home and 103 were seen at a health care facility; 28 were hospitalized and 11 received naloxone. Of the 15 pediatric cases in the Adverse Events Reporting System data set, all were hospitalized, and 13 had ocular exposures only.

CONCLUSIONS

All children < or =5 years of age with confirmed brimonidine ingestions should be medically evaluated and monitored for an extended period. Indications for the use of naloxone in brimonidine poisoning remain uncertain.

Treating type 2 diabetes: how safe are current therapeutic agents?

Sulphonylureas (SUs) and biguanides (metformin) are the current mainstays in the treatment of type 2 diabetes (T2DM) and represent the most commonly used oral hypoglycaemic agents (OHAs). In recent years, a variety of new OHAs have become available, including thiazolidinediones, glinides, alpha-glucosidase inhibitors, glucagon-like peptide-1 agonists, amylin analogues and dipeptidyl peptidase-IV inhibitors, providing physicians with a larger therapeutic catalogue than ever before. The traditional drugs metformin and SUs have an established safety profile through long-term use. However, long-term clinical trials and routine use are lacking for many of the new agents, and some potentially serious side effects have been reported with several of these compounds. Until adequate data is obtained, it is difficult to assess the risk-benefit ratio of these agents in relation to the traditional drugs. Until that becomes fully documented, it may be wise to start pharmacologic treatment of patients on an individual basis, weighing the benefits and costs of each medication. Thus, there remains a place for well-established drugs that have a proven safety record and are supported by years of clinical use for the treatment of T2DM.

Extended-release glipizide overdose presenting with delayed hypoglycemia and treated with subcutaneous octreotide

The onset of symptomatic hypoglycemia in children with ingestions of second-generation sulfonylureas has never been documented to be later than 21 hours post-ingestion. We report a case with the longest known interval, 45 hours, between ingestion of a sulfonylurea and the onset of hypoglycemia requiring medical intervention. The hypoglycemia was severe and required multiple dextrose boluses in addition to continuous dextrose infusion for 36 hours. This patient was also treated with multiple doses of subcutaneous octreotide because of persistent hypoglycemia despite the above management. This case represents the first report of subcutaneous octreotide used as a treatment for pediatric hypoglycemia secondary to sulfonylurea exposure.

Pattern of pediatric zolpidem ingestions reported to Texas poison control centers, 2000 to 2006

OBJECTIVES

The purpose of this study was to describe the pattern of zolpidem ingestions by young children reported to poison control centers.

METHODS

Cases were all zolpidem ingestions by children 0 to 5 year old reported to Texas poison control centers during 2000 to 2006. Multiple substance ingestions were excluded. The distribution of cases was described with respect to such demographic and clinical factors as patient gender, ingestion reason, ingestion site, management site, and medical outcome.

RESULTS

There were a total of 463 cases, all unintentional exposures. The patient was male in 52.2% of the cases, and the exposure occurred at the patient's own home in 92.8% of the cases. The patient was managed on-site in 54.4% cases, already at or en route to a health care facility in 29.6% cases, and referred to a health care facility in 16.0% cases. Of the 322 cases with a known final medical outcome, 59.0% had no effect, 35.1% had minor effects, and 5.9% had moderate effects.

CONCLUSIONS

Pediatric ingestions of zolpidem alone reported to Texas poison control centers most frequently resulted in at most minor effects and were often managed at home.

Deaths from reptile bites in the United States, 1979-2004

INTRODUCTION

Bites from reptiles cause thousands of injuries but fortunately few deaths in the U.S. each year. This article reviews deaths from reptile bites over the last 25 years.

METHODS

Mortality data was obtained using CDC WONDER to evaluate deaths that occurred from 1979 to 2004 due to reptile bites. Information on race, gender, ages, and state where death occurred is reported.

RESULTS

There were 134 deaths reported over this 25-year time period. Whites were 93.3% of the victims, and males were 79.1% of the victims. The age group reporting the most deaths was the 25 to 34 year old category. There were 17 (12.7%) victims less than 15 years of age, and 25 (18.7%) victims older than 65 years of age. Seventy-five of the fatalities (55.9%) occurred in five states.

CONCLUSIONS

An average of five deaths occurs from reptile bites each year in the U.S. White males living in the Southern part of the United States are more likely to be the victim of a fatal reptile envenomation.

Acetaminophen-associated hepatic injury: evaluation of acetaminophen protein adducts in children and adolescents with acetaminophen overdose

Acetaminophen protein adducts (APAP adducts) were quantified in 157 adolescents and children presenting at eight pediatric hospitals with the chief complaint of APAP overdose. Two of the patients required liver transplantation, whereas all the others recovered spontaneously. Peak APAP adducts correlated with peak hepatic transaminase values, time-to-treatment with N-acetylcysteine (NAC), and risk determination per the Rumack-Matthews nomogram. A population pharmacokinetic analysis (NONMEM) was performed with post hoc empiric Bayesian estimates determined for the elimination rate constants (k(e)), elimination half-lives (t(1/2)), and maximum concentration of adducts (C(max)) of the subjects. The mean (+/-SD)k(e) and half-life were 0.486 +/- 0.084 days(-1) and 1.47+/- 0.30 days, respectively, and the C(max) was 1.2 (+/-2.92) nmol/ml serum. The model-derived, predicted adduct value at 48 h (Adduct 48) correlated with adductC(max), adduct T(max), Rumack-Matthews risk determination, peak aspartate aminotransferase (AST), and peak alanine aminotransferase (ALT). The pharmacokinetics and clinical correlates of APAP adducts in pediatric and adolescent patients with APAP overdose support the need for a further examination of the role of APAP adducts as clinically relevant and specific biomarkers of APAP toxicity.