2002 annual report of the American association of poison control centers toxic exposure surveillance system

Inhalant abuse: a case of hemoptysis associated with halogenated hydrocarbons abuse

An 18-year-old man presented to a community emergency department with increasing shortness of breath and fever. His condition was diagnosed, and he was treated as an inpatient for bilateral pneumonia associated with hypoxemia. When his condition became worse, he acknowledged to deliberate inhalation of keyboard cleaner and to having hemoptysis. Before his death on hospital day 11, known causes of alveolar hemorrhage were excluded. We postulated a cause-and-effect relationship, adding alveolar hemorrhage to the known complications of inhalant abuse.

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.

Digitalis must be banished from the table: a rare case of acute accidental Digitalis intoxication of a whole family

Advanced Digitalis intoxication is a rare event, mainly associated with overdose in patients with Digitalis therapy. We report an unusual case of acute 'familiar' digitalis poisoning in three patients who had eaten potato dumplings flavoured with leaves of Borago officinalis L. unconsciously mixed with leaves of Digitalis purpurea L. A complicated clinical course with marked bradyarrhythmias was presented, with good evolution thanks to the use of digoxin-specific antibody Fab fragments. The theme of the domestic use of plants with medicinal effects has been treated and discussed.

Medication overdoses leading to emergency department visits among children

BACKGROUND

The high prevalence of medication use increases the potential for medication overdoses, especially among children.

PURPOSE

This paper describes the burden of unintentional pediatric medication overdoses in order to target new prevention efforts.

METHODS

Data were analyzed in 2007 and 2008 from the National Electronic Injury Surveillance System, collected January 1, 2004, through December 31, 2005, to estimate the number of emergency department visits resulting from unintentional medication overdoses among children aged <or=18 years in the U.S. These data were analyzed by patient demographics, overdose cause, and implicated products, and compared to visits for nonpharmaceutical consumer product poisonings.

RESULTS

Based on 3034 cases, an estimated 71,224 emergency department visits for medication overdoses were made annually by children aged <or=18 years, representing 68.9% of emergency department visits for unintentional pediatric poisonings. The rate of unintentional poisonings from medications was twice the rate of those from nonpharmaceutical consumer products (9.2 visits per 10,000 individuals per year [95% CI=7.3, 11.0] vs 4.2 per 10,000 individuals per year [95% CI=3.3, 5.0]). Four fifths (82.2%) of visits for medication overdoses were from unsupervised ingestions (children accessing medications on their own); medication errors and misuse resulted in 14.3% of visits. Most visits (81.3%) involved children aged <or=5 years, and commonly available over-the-counter medications were implicated in one third (33.9%) of visits.

CONCLUSIONS

Medication overdoses among children, notably unsupervised ingestions, represent a substantial burden in terms of emergency department visits and hospitalizations. New efforts to prevent pediatric medication overdoses are needed.

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.

Clinician Validation of Poison Control Center (PCC) Intentional Exposure Cases Involving Prescription Opioids

Poison Control Center (PCC) cases involving intentional ingestion, injection or inhalation of prescription opioids are a potentially valuable source of information on the abuse and misuse of these products. This study sought to validate PCC classifications of prescription opioid intentional exposure cases against clinical diagnostic criteria. 4,321 cases were reviewed. PCC-clinician concordance was good to excellent for Withdrawal, Abuse, and Suicide (kappa statistics: 0.73, 0.53, 0.48, respectively), but poor for Misuse and Intentional Unknown (Specific motive not known). Interrater reliability among clinicians was good (weighted kappa range: 0.56-0.68). Results demonstrate the degree of compatibility between PCC and standard nosologic classifications.

Today's Food System: How Healthy Is It?

With its focus on the quantity of production, often to the exclusion of other goals, today's food system is on an unsustainable course. The problem begins with and is driven by industrialized production of both crops and animals. Industrialization is a product of technological change, public policy, and, most recently, globalized trade. The lack of sustainability derives from reliance on the intensive use of nonrenewable and hard-to-renew resources-soil, antibiotics, fresh water, and fossil fuels, for example-but also from the waste and pollution created by the industrial model. For at least 50 years, American agriculture policies have promoted production of, and ultimately lower market prices for, commodity crops like corn, wheat, and soybeans. Over the last 3 decades in particular, these "cheap food" policies have exacerbated the negative impacts of an industrialized agriculture on the health of the agro-ecosystem, as well as on the health of the humans who must share and be sustained by it. Sustainability and health are two sides of the same food system coin. Policies that put US food production on more sustainable footing can help aid in public efforts to address the myriad crises confronting both the food and health systems.

Acute topiramate overdose--clinical manifestations

INTRODUCTION

The clinical manifestations of acute topiramate toxicity are described.

METHODS

Seven cases of acute and acute-on-chronic topiramate toxicity observed in two clinical units of Polish Poison Control Centers in 2004-2005 were analyzed.

RESULTS

The patients were 4 women and 2 men aged between 16 and 38 (mean 21.0 +/- 8.4) years. The doses of topiramate ranged from 10.7 to 218 mg/kg. The most frequent symptom was somnolence (66.7%) and, vertigo, agitation, and mydriasis were less common (33.4%). One patient who was not previously treated with topiramate experienced three secondarily generalized tonic-clonic seizures. Metabolic acidosis, lasting for 3-7 days, was observed in four cases, and did not influence the outcome.

CONCLUSIONS

The clinical manifestations of acute poisonings with topiramate ranged from asymptomatic to severe, but no distant sequelae or fatalities were observed. The course of acute poisoning seems to be more severe in patients who were not previously treated with topiramate.

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.

Illicit cathinone (“Hagigat”) poisoning

INTRODUCTION

Khat leaves (mainly cathinone and cathine) have been chewed for centuries as stimulants. Hagigat (capsules of 200 mg cathinone) have been marketed in Israel as a natural stimulant and aphrodisiac. The consequences of illicit exposure to cathinone are reported.

METHODS

Prospective observational study of calls to the Poison Center regarding exposure to Hagigat during the course of 10 months. Demographic and clinical data were abstracted from patients' records and telephone follow up was performed.

RESULTS

Data of 34 consecutive patients aged 16-54 years were analyzed. The amount consumed was (1/2)-6 capsules (ingestion-32, sniffing-2). Main clinical manifestations were headache, vomiting, hypertension, nausea, tachycardia, dyspnea, chest pain, and myalgia. Main complications were myocardial ischemia (3), pulmonary edema (2), and intracerebral hemorrhage (1), all in young subjects. Treatment was supportive; one patient underwent neurosurgery.

CONCLUSION

Exposure to illicitly synthesized cathinone is associated with serious cardiovascular and neurological toxicity, even in young subjects.

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.

Drug-induced serotonin syndrome: a review

Serotonin syndrome, or serotonin toxicity (ST), is a clinical condition that occurs as a result of an iatrogenic drug-induced increase in intrasynaptic serotonin levels primarily resulting in activation of serotonin(2A) receptors in the central nervous system. The severity of symptoms spans a spectrum of toxicity that correlates with the intrasynaptic serotonin concentration. Although numerous drugs have been implicated in ST, life-threatening cases generally occur only when monoamine oxidase inhibitors are combined with either selective or nonselective serotonin re-uptake inhibitors. The triad of clinical features consists of neuromuscular hyperactivity, autonomic hyperactivity and altered mental status, which may present abruptly and progress rapidly. The awareness of ST is crucial not only in avoiding the unintentional lethal combination of therapeutic drugs but also in recognizing the clinical picture when it occurs so that treatment can be promptly initiated. In this review, the pathophysiology, clinical features, implicated drugs, diagnosis and treatment of ST are discussed.

Water Decontamination of Chemical Skin/Eye Splashes: A Critical Review

Skin/eye chemical splashes are a significant workplace problem. Initial water decontamination is usually recommended, but there are few well-conducted experimental animal and human studies of efficacy. An extensive review of the literature and other available information sources was performed to define the scope of the problem and critically review the evidence for water decontamination efficacy. Although water decontamination can decrease the severity of chemical skin/eye burns, it cannot completely prevent them. An ideal replacement decontamination solution would be sterile, nontoxic, chelating, polyvalent, amphoteric, and slightly hypertonic to retard skin or corneal penetration of the chemical.

Altered Mental Status from Olanzapine Overdose Treated with Physostigmine

BACKGROUND

Olanzapine is commonly prescribed to patients with schizophrenia. One retrospective study demonstrates the efficacy of physostigmine in reversing mental status changes induced by olanzapine. We report two patients with delirium due to confirmed olanzapine overdose treated with physostigmine. One patient's mental status transiently returned to normal. The other patient completely recovered. CASE 1: A 25-year-old man ingested 300 mg of olanzapine. On presentation, he was agitated, delirious, tachycardic, had dry skin and mucous membranes, and dilated pupils (6 mm) minimally reactive to light. Physostigmine, 0.5 mg, was given intravenously (IV) without effect. Additional physostigmine doses of 1.5 mg IV administered 5 minutes later and then 1 mg IV resulted in the patient having a clear sensorium and normal mentation. The patient's mental status continued to remain normal for the duration of his hospital stay. Olanzapine was identified in the urine by high performance liquid chromatography. CASE 2: A 20-year-old female ingested 600 mg of olanzapine. On presentation, she was tachycardic, obtunded, and minimally responsive to painful stimuli, with decreased bowel sounds, dry skin and dry mucous membranes. Physostigmine, 2 mg, was given IV. Shortly thereafter she regained full consciousness and began speaking coherently. She remained in this condition for approximately 30 minutes, and then became obtunded. Her serum olanzapine concentration was 1230 ng/mL. No further doses of physostigmine were administered. On day 3 of admission her mental status returned to normal.

CONCLUSION

We report two cases of olanzapine-induced mental status changes treated with physostigmine. The utility of physostigmine as a safe or necessary antidote in the setting of olanzapine overdose remains to be determined.

A New Predictor of Toxicity Following Acetaminophen Overdose Based on Pretreatment Exposure

INTRODUCTION

Despite extensive clinical experience, no dose-response curve exists for acetaminophen toxicity in man. The absence of accurate toxicodynamics has hampered efforts to optimize patient therapy and to identify risk modifiers following overdose. We set out to parameterize both the degree and duration of pretreatment exposure into a single, continuous measure of exposure, which will serve as the x-axis of an eventual dose-response curve.

METHODS

The model was constructed from pharmacokinetic first principles, using as inputs the vertical distance above the Rumack-Matthew nomogram line (expressed as the equivalent serum acetaminophen concentration 4 h after ingestion) and the delay to antidote therapy (tNAC). A no-effect dose ([APAP]threshold) and lag time (ti) were assumed.

RESULTS

The area under the serum acetaminophen concentration vs. time curve bounded by [APAP]threshold, ti and tNAC represents our proposed time-weighted measure of exposure. We demonstrate that this non-negative area estimates the cellular burden of toxic adducts formed following overdose. This measure is also easily calculated at patient presentation using clinical data and allows for both declining serum acetaminophen concentrations and variable delays to antidote therapy.

DISCUSSION

We describe a new, pharmacokinetically based measure of exposure following acute acetaminophen overdose treated with N-acetylcysteine. Using this measure should enhance the analysis of nonexperimental clinical data and permit more accurate characterization of acetaminophen toxicodynamics. Ultimately, this approach may facilitate progress on many of the long-standing controversies regarding acetaminophen toxicity in man.

Trends in emergency department use of gastric lavage for poisoning events in the United States, 1993–2003

OBJECTIVE

To determine current trends in the use of gastric decontamination for the emergency department (ED) treatment of overdose patients.

METHODS

In the National Health Ambulatory Medical Care Survey (NHAMCS), a weighted sampling of U.S. EDs, overdose-related visits were examined using ICD-9 CM E codes and NHAMCS' "reason-for-visit" classification.

RESULTS

From 1993 to 2003 there were an estimated 11.68 million ED-treated poisoning events. Some 13.7% of those treated were lavaged. Rates fell significantly, from an annual average of 18.7% of cases during 1993-97 to 10.3% during 1998-2003 (p < 0.001). Controlling for year, urgency, and admission status in multivariate logistic modeling, lavage was significantly and positively associated with private insurance payor status, younger age (<30), female gender, white race, 8 PM-8 AM presentation, and intentional rather than unintentional overdose.

CONCLUSION

ED use of gastric lavage in poisoned patients has decreased significantly over the past decade but varies by demographic and non-clinical factors.

Pyrethroid Insecticides: Advances and Challenges in Biomonitoring

Pyrethroid insecticides have a wide variety of applications throughout the world. They are structurally diverse chemicals that are synthetically derived from naturally occurring pyrethrin insecticides. Significant advances in analytical chemistry have led to the development of biomarkers of exposure to pyrethroids, and these methods are currently being applied to study exposure in the general population. This article reviews the chemistry and toxicology of pyrethroid insecticides, with an emphasis on the development of biomarkers to assess environmental exposure. Future challenges in the application of these biomarkers in epidemiological studies are explored, as is a need for improved understanding of the toxicokinetics of pyrethroids in humans.

Effect of Oral Calcium Disodium EDTA on Iron Absorption in a Human Model of Iron Overdose

OBJECTIVE

Anecdotal case reports and animal models have suggested that the administration of CaNa2EDTA (EDTA) may be effective in reducing the absorption of iron after an oral iron overdose. We designed this study to determine the effect of orally administrated EDTA with or without activated charcoal (AC) on iron absorption after a mild iron ingestion in healthy human volunteers.

METHODS

A randomized, crossover study was conducted in eight healthy human volunteers. All subjects ingested 5 mg/kg of elemental iron in the form of ferrous sulfate. One hour post ingestion, subjects were randomized to receive 35 mg/kg EDTA, EDTA plus 50 grams of AC, or water. Serial iron levels were obtained at baseline and every hour for the first 6 hours, then at 8, 12, and 24 hours. A 2-week washout was used between study arms. The Kruskal-Wallis test was used for the following comparisons between treatment groups: baseline serum iron levels, area under time-concentration curves (AUCs) from baseline to 12 hours and baseline to 24 hours, and peak iron levels.

RESULTS

Baseline serum iron levels did not differ among the three treatment groups (p = 0.844). AUCs were not different among groups (p = 0.746 for 12 hr, p = 0.925 for 24 hr). AUC medians (with 95% binomial confidence bounds) for control, EDTA, EDTA + AC groups, respectively, for 12 hr were: 2813 (2298, 3561), 2570 (1669, 3476), and 2654 (2125, 3600); and for 24 hr were: 4083 (3488,5314), 4139 (2666, 5547), and 4274 (3336, 5577). Peak serum iron levels did not differ among treatment groups (p = 0.481). Peak iron level medians in microg/dL (with 95% binomial confidence bounds) were for control: 329 (253, 382), for EDTA: 271 (184, 375), and for EDTA + AC: 285 (229, 352).

CONCLUSION

Orally administered EDTA did not significantly reduce iron absorption when administered 1 hour post iron ingestion during the 12 or 24-hour period following the ingestion of 5 mg/kg of elemental iron in healthy human volunteers.

Selective serotonin re-uptake inhibitor warnings and trends in exposures reported to poison control centres in Texas

OBJECTIVES

Since January 2002, the US Food and Drug Administration (FDA) has issued a number of advisories about the use of antidepressants, including selective serotonin re-uptake inhibitors (SSRIs). These advisories may have influenced the number of SSRI exposures reported to poison control centres. The purpose of this study was to examine time trends in SSRI exposures reported to poison control centres in Texas with respect to the timing of the various advisories.

STUDY DESIGN

Retrospective review of data from poison control centres.

METHODS

Cases were divided into two groups: (1) paroxetine exposures and (2) other SSRI exposures reported to poison control centres in Texas between 1998 and 2006. The month and year of the call, and patient age and gender were identified. The mean monthly number of ingestions for the two groups was calculated for six time periods related to the FDA advisories.

RESULTS

The mean monthly number of total paroxetine ingestions between January 2002 and June 2003 was 77.6. This declined by 23.3% to 59.6 in July 2003-March 2004 after an advisory about the risk of suicidality in youths using paroxetine. Comparable mean monthly numbers for patients aged <20 years were 33.3 and 20.3, respectively (decline of 38.9%); and for patients aged >or=20 years were 44.0 and 38.6, respectively (decline of 12.4%). Mean monthly numbers for total other SSRI ingestions were 206.4 and 243.1, respectively (increase of 17.8%).

CONCLUSIONS

The FDA advisory in June 2003 appeared to initiate a decline in paroxetine ingestions, particularly among patients aged <20 years, but did not appear to influence other SSRI ingestions reported to poison control centres in Texas.

Adult metformin ingestions reported to Texas poison control centers, 2000–2006

Metformin is an oral hypoglycemic agent used in the management of type 2 diabetes mellitus. Limited information exists on adult metformin ingestions reported to poison control centers. The distribution of adult metformin ingestions reported to Texas poison control centers during 2000–2006 was determined for various factors. In addition, triage guidelines for the management of isolated ingestions were drafted. Of 1528 total metformin ingestions, 58% involved coingestants. Of the 264 ingestions of metformin alone, where the final medical outcome was known, dose ingested was reported for 66%. The mean reported dose was 4739 mg (range 500–60,000 mg). Ingestions of ≤2500 mg and >5000 mg reported doses differed with respect to the proportion involving suspected attempted suicide (6% versus 81%), serious final medical outcome (3% versus 19%), and referral to a health care facility (3% versus 83%). Using 5000 mg as a threshold dose for referral to a health care facility, 91% of cases not already at or en route to a health care facility were managed according drafted triage guidelines.

The poisoned child in the pediatric intensive care unit

Acutely poisoned children remain a common problem facing pediatricians working in acute care medicine in the United States and worldwide. The management of such children continues to be challenging, and their care has evolved throughout the years. The concept of gastric decontamination in acute poisoning has significantly changed over the past 10 years, and many of the previously used techniques have been abandoned or fallen out of favor for lack of evidence to their benefit or unacceptable serious risks and side effects. Supportive care continues to be the cornerstone in managing most poisoned children. Only a few patients benefit from antidotes or specific interventions.

Verapamil toxicity dysregulates the phosphatidylinositol 3-kinase pathway

OBJECTIVES

Recent animal research and clinical case reports suggest benefit from high-dose insulin therapy (HDIT) for the treatment of calcium channel blocker (CCB) toxicity. One molecular signaling pathway, the phosphatidylinositol 3-kinase (PI3K) pathway, that contributes to CCB toxicity and the efficacy of HDIT, was examined for a role in this phenomenon.

METHODS

A differentiated 3T3-L1 adipocyte model system was utilized to characterize metabolic and molecular signaling events dysregulated in response to acute CCB toxicity. Glucose uptake assays were performed in the presence of representatives of three classes of CCB drugs, and the ability of HDIT to reverse observed inhibition was assessed. Western blot analyses were utilized to probe which insulin-dependent signaling pathway was inhibited by CCB toxicity.

RESULTS

Representative compounds from the dihydropyridine and phenylalkylamine classes of CCBs were more effective at inhibiting glucose uptake in differentiated 3T3-L1 adipocytes than a representative from the benzothiazepine class. Phosphorylation at serine 473 of the Akt protein (P-Akt), a protein representing a common pathway for insulin receptors (IR), insulinlike growth factor receptors (IGFR), and hybrid receptors formed by IR and IGFR subunits, was abolished in the presence of toxic doses of the phenylalkylamine CCB verapamil. Phosphorylation at serine 473 of Akt was rescued in the presence high concentrations of insulin.

CONCLUSIONS

These data suggest that dysregulation of the insulin-dependent PI3K pathway is partially responsible for insulin resistance and the hyperglycemic state observed in response to acute CCB toxicity.

High-Dose Insulin in the Treatment of Antihypertensive Overdose

Objective

To describe a case of calcium channel blocker overdose along with an angiotensin-converting enzyme inhibitor and angiotensin receptor blocker, which was successfully treated with high-dose insulin with dextrose and potassium supplementation (HDIDK).

Case Summary

A 52-year-old woman was transferred to an admitting hospital after ingesting 14 tablets of trandolapril/verapamil SR ( Tarka)4 mg/240 mg, 15 to 16 tablets of olmesartan ( Benicar) 20 mg, and an unknown amount of (escitalopram) Lexapro combined with unknown quantities of alcohol and benzodiazepines. This combination caused hypotension and electrocardiogram changes. The patient was treated for hypotension-induced shock with epinephrine, glucagon, HDIDK, magnesium, and fluids. An insulin infusion ran for 24 hours. The patient was discharged to a psychiatric facility 3 days after admission.

Discussion

The non-dihydropyridine, verapamil, causes dilation of the coronary and peripheral vasculature by inhibiting the influx of calcium ions through L-type calcium channels. HDIDK is thought to be a useful treatment in the state of hypoinsulinemia, which prevents the uptake of glucose by myocytes and can lead to decreased inotropy and eventually shock. High-dose insulin allows glucose to be properly used for energy by the myocytes.

Conclusions

Currently HDIDK therapy is recommended as an adjunct to conventional therapy in calcium channel blocker poisoning only after fluids, high-dose calcium salts, and vasopressors. In this case, early implementation of HDIDK treatment was shown to shorten the length of therapy.

Carisoprodol abuse in Texas, 1998-2003

INTRODUCTION

Texas poison centers identified carisoprodol as a skeletal muscle relaxant that is subject to abuse, and this investigation explores the abuse reported by Texas poison centers.

METHODS

This study used data from six Texas poison centers to describe the epidemiology of carisoprodol abuse and drug identification (ID) calls from 1998 to 2003.

RESULTS

Drug ID and abuse calls were 217% higher in 2003 than in 1998. Although eastern and central Texas contains 43% of the state's population, this region reported 77% of all drug ID calls and 64% of abuse calls. For male patients, 51% of the calls were abuse calls and 37% were other human carisoprodol exposure calls. Patients from 13 to 19 years of age accounted for 17% of abuse calls and 9% of other human exposure calls. Among those human exposure calls with a known medical outcome, a higher percentage of abuse calls involved minor effects while a greater proportion of other human exposure calls involved outcomes that ranged from moderate effects to death.

CONCLUSIONS

Carisoprodol abuse is increasing in Texas and is substantially more common in the eastern part of the state. Carisoprodol abuse is much more likely, than other types of adverse carisoprodol exposures, to involve males and adolescents; and it less likely to involve adverse medical outcomes.

Pyrethrin and pyrethroid exposures in the United States: a longitudinal analysis of incidents reported to poison centers

INTRODUCTION

Citing the Food Quality Protection Act, the US Environmental Protection Agency (EPA) decided to phase out and eliminate organophosphate insecticide use in residential environments. The phase out process spanned from 2000 to 2005, and it may have resulted in increased consumer use of insecticides containing other active ingredients. This study utilized data from the national Poison Control Center to assess possible changes in exposure incidents involving pyrethrin and pyrethroid insecticides during the phase out of organophosphates from residential uses.

METHODS

We extracted pyrethrin and pyrethroid insecticide exposure data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) annual reports from 2000 to 2005. We examined pyrethrin and pyrethroid incidents by total exposures for each year, and we stratified exposures by age range, reason, number of cases treated in a health care facility, and medical outcome. Cases were examined as a proportion of all insecticide exposures. We calculated the annual incidence rates for exposures involving pyrethrin and pyrethroid insecticides of the population served.

RESULTS

Pyrethrin and pyrethroid exposures increased annually in number and as a percentage of all insecticide exposure incidents. The increase in cases was observed for all age categories and exposure reasons. A statistically significant correlation was observed between advancing years (2000-2005) and the number of pyrethrin and pyrethroid incidents (p<.01). While the number of incidents treated in a health care facility increased annually during the study period, the proportion was constant (0.185 +/- 0.012) over the six year period. During the study period, the incidence rate for pyrethrin and pyrethroid exposures increased each year. 44% of all medical outcomes data was recorded, and the majority of outcomes resulted in no symptoms (37%) or minor symptoms (53%).

CONCLUSION

TESS data showed a clear increase in cases involving pyrethrins and pyrethroids. The increase was temporally associated with the phase out of organophosphates from residential uses. In the future, medical toxicologists and poison control center personnel should be prepared to respond to an increasing number of pyrethrin and pyrethroid insecticide exposures.

Prospective observational multi-poison center study of ziprasidone exposures

BACKGROUND

Ziprasidone is an atypical antipsychotic associated with QTc prolongation during therapeutic use. We characterized the clinical manifestations associated with ziprasidone overdoses, in particular the incidence and severity of QTc prolongation.

METHODS

Four regional poison centers prospectively collected ziprasidone overdose data from August 1, 2003 to October 1, 2005. Cases were included if they were followed to known medical outcome and comprised single-substance ziprasidone exposures or with co-ingestants not associated with prolongation of the QTc interval.

RESULTS

Fifty-six ziprasidone exposures met inclusion criteria. The most common clinical effects were drowsiness (N=38, 67.9%) and tachycardia (N=19, 33.9%). QTc prolongation (>0.500 second) occurred in only one patient. Seven patients had QTc intervals of 0.450 to 0.500 second. Medical outcomes were coded as no effect (13, 23.2%), minor effect (21, 35.5%), moderate effect (20, 35.7%), or major effect (2, 3.4%).

CONCLUSION

Common clinical effects following ziprasidone overdose are drowsiness and tachycardia. Clinically significant QTc prolongation occurs infrequently.

Compliance with selective serotonin reuptake inhibitor triage guidelines by Texas poison control centers

Although 2% of exposures reported to U.S. poison control centers involve selective serotonin reuptake inhibitors (SSRI), many poison control centers do not have standardized guidelines for the management of these exposures. Recently, such guidelines were published, although the utility of these guidelines has not been evaluated. Cases evaluated in this study are all ingestions of SSRI alone reported to Texas poison control centers during 2000-2006. A simplified version of the published management guidelines triage algorithm was created, and the proportion of cases that were managed according to these guidelines was calculated. Of the total cases, 85% not already at/en route to a health care facility and 88% already at/en route to a health care facility were managed according to the simplified algorithm. The respective rate ranges were 82-89% and 83-90% among the 6 poison control centers and 77-86% and 80-90% among the 6 specific SSRI. The majority of ingestions of SSRI alone reported to Texas poison control centers during a recent 7-yr period were managed according to a simplified version of recommended triage algorithm. This was the case for all of the poison control centers and all of the specific SSRI.

Gemfibrozil ingestions reported to Texas poison control centers, 2000-2005

Review of the literature failed to identify any information on potentially adverse ingestions of the cholesterol-lowering drug gemfibrozil (GEM) reported to poison control centers. Data from Texas poison control centers were used to describe the pattern of isolated GEM ingestions reported during 2000-2005. A total of 118 cases were identified. The mean maximum dose ingested was 2407 mg (range 300-18,000 mg) or 3.3 tablets/capsules (range 1-30 tablets/capsules). The patient was male in 55% of the cases. The most common circumstances of the exposure were unintentional therapeutic error (49%), general unintentional (34%), and suspected attempted suicide (11%). The management site was on site (84%), already at/en route to a health care facility (10%), referred to a health care facility (5%), and other (2%). The ingestion considered potentially toxic in 3% of the cases and no deaths were reported. A specific adverse clinical effect was listed for 9% of the cases, being gastrointestinal (5%), neurological (3%), or cardiovascular (1%). A specific treatment was listed for 54% of the cases, most frequently decontamination by dilution (39%) or food (15%). Potentially adverse isolated GEM ingestions reported to poison control centers generally do not involve serious medical outcomes and are successfully managed at home with a favorable outcome.

An alcohol oxidase dipstick rapidly detects methanol in the serum of mice

BACKGROUND

Patients presenting with ingestions of methanol and ethylene glycol pose a significant challenge to emergency physicians. The decision to initiate antidotal therapy must be made quickly and is currently based on the presence of indirect signs, symptoms, and laboratory tests, because no real-time diagnostic test exists to measure these substances.

OBJECTIVES

To determine whether a commercially available ethanol-in-saliva detecting dipstick (ALCO-Screen) would be a reliable and rapid indicator of toxic alcohol presence in the serum of an animal model.

METHODS

Fifty mice randomly received intraperitoneal doses of methanol, ethylene glycol, or ethanol to induce serum concentrations of approximately 5-400 mg/dL. Thirty minutes after injection, serum was obtained. Serum was both applied to the dipstick and frozen for definitive concentration determination by gas chromatography. After 2 minutes, dipsticks were evaluated for color change by a blinded observer and photographed to be evaluated by other blinded observers at a later time.

RESULTS

All concentrations of methanol > or =5 mg/dL consistently caused a color change on the ALCO-Screen. Ethylene glycol reliably caused a color change at > or =300 mg/dL. There was significant agreement among multiple observers whether or not color change had occurred using the ALCO-Screen.

CONCLUSIONS

A commercially available dipstick that uses an alcohol oxidase colorimetric reaction reliably and rapidly detects very low serum concentrations of methanol but not ethylene glycol in this animal model. This color change is easily detected by most observers.

Pediatric montelukast ingestions reported to Texas poison control centers, 2000-2005

Limited information exists on the toxicity of pediatric ingestions of the drug montelukast used in the treatment of chronic asthma. All ingestions of montelukast involving children age 0-5 yr reported to Texas poison control centers during 2000-2005 were retrieved. For a subset of cases where the final medical outcome and dose in milligrams or milligrams per kilogram were known, the pattern of exposures by final medical outcome and management site was evaluated. There was a total of 3698 cases. Of those cases with a known final medical outcome and dose, the mean dose in milligrams was 42.5 mg (range 0.4-536 mg) and the mean dose in milligrams per kilogram was 3.36 mg/kg (range 0.18-33.71 mg/kg). The final medical outcome was no observed effect in 95% of the cases and minor effect in the remainder of the cases. The patient was managed on site in 80% of the cases. The proportion of cases with a minor effect increased from 5% for ingested dose of < or = 100 mg to 10% for > 100 mg but was 5% for dose < or = 5 mg/kg and > 5 mg/kg. The proportion of cases managed with health care facility involvement increased from 15% for ingested dose of < or = 100 mg to 56% for > 100 mg and rose from 10% for dose < or = 5 mg/kg to 47% for dose > 5 mg/kg. Pediatric montelukast ingestions of doses up to 536 mg or 33.71 mg/kg do not appear likely to result in serious adverse effects and usually can be managed at home.

Cessation of nail growth following Bajiaolian intoxication

Bajiaolian (Dysosma pleianthum), a species in the Mayapple family (Podophyllum pelatum), has been widely used as a traditional Chinese herbal medication for the remedies of snake bite, tumor growth, post-partum recovery, and acne. It has also been used in western medicine, especially topically for various skin lesions. Both oral ingestion and dermal application may result in severe toxicity. The clinical presentations reported after Bajiaolian poisoning include nausea, vomiting, diarrhea, abdominal cramps, tachycardia, orthostatic hypotension, paralytic ileus, urinary retention, hepatorenal dysfunction, leukocytosis followed by leukopenia, thrombocytopenia, prolonged areflexia, prolonged paraethesia and sensory ataxia, dizziness, fever, memory impairment, hallucinations, paranoia, convulsion, fainting, and coma. There are no previous reports in the literature about the cessation of nail growth as a clinical presentation following Bajiaolian poisoning. We present a case of nail growth that was halted for more than seven years after a single case of Bajiaolian poisoning.

Are one or two dangerous? Diphenoxylate-atropine exposure in toddlers

Lomotil (Pfizer Inc., New York, NY) (diphenoxylate-atropine) is said to be potentially toxic to toddlers with exposure to as little as one to two tablets. A review of the data on diphenoxylate-atropine poisonings from the American Association of Poison Control Centers annual reports, review articles, and case series disputes this view. Fatalities associated with diphenoxylate-atropine have been reported in toddlers after repetitive or incorrect dosages. Fortunately, trends in pediatric diphenoxylate-atropine ingestions are decreasing. We review the management, trends, and current concepts regarding pediatric diphenoxylate-atropine ingestions.

Are One or Two Dangerous? Calcium Channel Blocker Exposure in Toddlers

Unintentional pediatric ingestions of calcium channel blockers are increasing in frequency due to increased use of this antihypertensive class. Potential toxic effects include severe refractory hypotension and death; however, the true toxicity of unintentional pediatric ingestions of 1-2 pills is poorly defined. A literature review was conducted to more closely determine toxic and lethal dosages of calcium channel blockers in the pediatric population under 6 years of age. Results indicate that, although most accidental pediatric ingestions are asymptomatic, a small number do result in cardiovascular instability or even death. The dihydropyridines, particularly nifedipine, and the phenylalkylamine verapamil are most often implicated in symptomatic ingestions. There are no adequate data to identify which children are predisposed to illness, or to determine cutoffs for toxic dosages. However, ingestions of only one pill have been documented to cause severe symptoms, including death. Thus, emergency evaluation to assess potential toxicity is necessary, and gastrointestinal decontamination and in-hospital observation of at least 6 h after toxic ingestion for regular release medications, and 12-24 h after toxic ingestion for sustained release medications is recommended for all cases of unintentional calcium channel blocker ingestion in children younger than 6 years of age.

Effects of adenosine receptor antagonists on amitriptyline-induced vasodilation in rat isolated aorta

BACKGROUND

Although we have previously demonstrated the beneficial effects of adenosine receptor antagonists in preventing cardiovascular toxicity of amitriptyline in rats, it is not clear whether adenosine receptors in heart or in vasculature are dominant. The aim of the current study was to investigate the role of adenosine A(2a) receptors on amitriptyline-induced vasodilation in rat isolated aorta.

METHODS

After determining EC(80) of noradrenalin (NA) (the concentration of noradrenalin that produces 80% of maximal contractile response) as 10(-5)M, the IC(50) value of amitriptyline was measured in rat isolated aorta (the drug concentration causing a half- maximal inhibition of contractile responses to NA); IC(50) of amitriptyline was then compared in the presence of the DPCPX (a selective adenosine A(1) antagonist), CSC (a selective A(2a) antagonist) or DMSO (a solvent for adenosine antagonists). Statistical analysis was done using the Student t test.

RESULTS

Amitriptyline-inhibited 49.9 +/- 3.7 % contractile response to NA on aorta segments at 1.8 x 10(-5)M (IC(50)). While DPCPX increased amitriptyline-induced inhibition on contractile response to NA dose dependently, CSC decreased the contractile response to NA only at 10(-5)M. DMSO did not change amitriptyline-induced IC(50).

CONCLUSION

Adenosine A(2a) receptor stimulation seems to be responsible partly for amitriptyline-induced vasodilation and hypotension since the adenosine A(1) antagonist, DPCPX, increased amitriptyline-induced vasodilation in rat isolated aorta.

Toxic Exposure Surveillance System (TESS)-based characterization of U.S. non-native venomous snake exposures, 1995-2004

BACKGROUND

Non-native (exotic) snake exposures in the United States have not been systematically characterized.

METHODS

The Toxic Exposure Surveillance System (TESS) database of the American Association of Poison Control Centers was analyzed to quantify the number and types, demographic associations, clinical presentations, managements and outcomes, and the health resource utilization of non-native snake exposures.

RESULTS

From 1995 through 2004, there were 399 non-native exposures in the TESS database. Of these, 350 snakes (87%) were identified by genus and species, comprising at least 77 different varieties. Roughly equal percentages of snakes originated in Asia, Africa and Latin America, with a smaller number from the Middle-East, Australia, and Europe. Nearly half were viperids and a little more than a third were elapids. The vast majority of exposed individuals were adults. However, almost 15% were aged 17 years or less, and almost 7% were children aged 5 years or younger. Eighty-four percent were males. The vast majority of exposures occurred at the victim's own residence. Over 50% were evaluated at a healthcare facility, with 28.7% admitted to an ICU. Overall, 26% of patients were coded as receiving antivenom treatment. Coded outcomes were similar between viperid and elapid envenomations. There were three deaths, two involving viperid snakes and one elapid. Enhancements to the TESS database are required for better precision in and more complete characterization of non-native snake envenomations.

Backyard mushroom ingestions: no gastrointestinal decontamination--no effect

Treating the unintentional "backyard" mushroom ingestion continues to be controversial. A review of pediatric "backyard" mushroom ingestions was conducted. A Regional Poison Information Center (RPIC) conducted a retrospective review of all mushroom ingestions in children younger than 6 years of age. Data were extracted from the RPIC electronic record system for the years 2000-2003. All exposures that involved "backyard" mushroom ingestions with no gastrointestinal decontamination were included. There were 322 mushroom exposures in children younger than 6 years of age reviewed. The mean age reported was 2.1 years (SD +/- 1.18). All exposures with a definitive outcome had a 24-h follow-up post-exposure to make this determination. There was no effect in 256 cases (79.5%); minor effect in 6 (1.9%); judged as nontoxic, expect no effect in 20 (6.2%); minimal clinical effects possible in 31 (9.6%); and unrelated effect in 9 (2.8%). It was concluded that "backyard" mushrooms do not present a toxicity hazard in unintentional pediatric exposures and require no gastrointestinal decontamination.

Plant poisoning

Each year over 100,000 exposures to toxic plants are reported to poison centers throughout the United States. Most of these exposures are of minimal toxicity largely because of the fact that they involve pediatric ingestions, which are of low quantity. The more serious poisonings usually involve adults who have either mistaken a plant as edible or have deliberately ingested the plant to derive perceived medicinal or toxic properties. The plants within this manuscript have been chosen because they have been documented to cause fatalities or account for emergency medicine visits. In this discussion, plants are grouped by their toxins rather than on the basis of their taxonomy.