The predictive value of heart rate in determining clinical course after a bupropion overdose.

INTRODUCTION: Bupropion is a popular antidepressant due to its favorable side effect profile and indications for smoking cessation and weight loss. Due to the possibility of delayed onset seizure and other adverse outcomes after bupropion overdose, patients are often observed for periods of 12-24 hours following suspected ingestion. Tachycardia is a clinical predictor that holds promise in differentiating cases at risk for seizures from low-risk cases that do not require prolonged observation. This study assessed whether heart rate within the first eight hours of presentation can identify cases that do not require extended observation. METHODS: This is a retrospective cohort study of all supra-therapeutic bupropion cases from two hospital systems between 2010 and 2022. RESULTS: Data from 216 charts were included. Seizures, hypotension, and dysrhythmias occurred in 19 percent (n = 41), 1.4 percent (n = 3), 0.9 percent (n = 2) respectively. One patient died. Delayed adverse effects were rare (n = 4); they occurred from 14 hours to 28 hours post-ingestion. Maximum heart rate in eight hours was associated with a risk of adverse outcomes. (odds ratio, 1.07; 95 percent confidence interval: 1.05 to 1.09; P < 0.001). An eight hour maximum heart rate threshold of 104 beats/minute had a negative predictive value of 100 percent (95 percent confidence interval: 96.7 percent to 100 percent) for the occurrence of delayed adverse effects. All patients with delayed effects had tachycardia within five hours of emergency department arrival. DISCUSSION: Delayed adverse outcomes of seizures, hypotension, dysrhythmia, and death were uncommon in this cohort. Heart rate during the first eight hours of observation performs reliably as a screening test to identify patients at low risk for delayed adverse outcomes. This study is limited by its retrospective nature, the inability to ascertain time of ingestion for most cases and the lack of confirmatory laboratory testing. CONCLUSION: This study supports the use of an eight hour observation period when there are no other clinical signs of toxicity to warrant admission and if no co-ingestion or administration of substances that mask tachycardia are present.

Outcomes of pediatric ingestions of alcohol-based hand sanitizers during the COVID-19 pandemic.

INTRODUCTION: In July 2020, an outbreak of methanol-contaminated hand sanitizers in the United States prompted our regional poison center to implement a more conservative triage guideline for hand sanitizer exposures. All pediatric hand sanitizer ingestions of more than a "taste" were referred to a healthcare facility for assessment. We then evaluated the effect of this change on identifying patients with methanol poisoning. METHODS: This was a single-center, retrospective review of pediatric (<19 years) hand sanitizer ingestions reported to our poison center from May 1, 2020 through January 28, 2022. Methanol and ethanol concentrations were collected if available. RESULTS: During the study period, we received 801 calls regarding hand sanitizer exposure, of which 140 children were referred to a healthcare facility for hand sanitizer ingestions. Of those, 88 (63%) had methanol and/or ethanol concentrations measured. No child had a detectable methanol concentration, 78 had ethanol testing, and 12 had a detectable ethanol concentration. CONCLUSIONS: In this sample, no patient tested had a detectable methanol concentration. Children who consumed enough to have a detectable ethanol concentration were symptomatic or had an intentional ingestion. Asymptomatic children with unintentional ingestion of hand sanitizer were at low risk for methanol toxicity.

Fatal Yellow Oleander Poisoning Masquerading as Benign Candlenut Ingestion Taken for Weight Loss.

BACKGROUND: Candlenuts (Aleurites moluccana) and yellow oleander seeds (Thevetia peruviana) bear a physical resemblance to one another. Candlenuts are benign and marketed as weight loss supplements. Yellow oleander seeds, however, contain toxic cardioactive steroids; as few as 2 seeds may cause fatal poisoning. Because of their physical similarities, the potential for a lethal substitution exists. CASE REPORT: A 63-year-old woman presented to the emergency department with vomiting after ingesting 5 of what she believed to be candlenuts that were ordered online under the colloquial name "Nuez de la India" for the purpose of weight loss. She was bradycardic (nadir pulse of 30 beats/min) and hyperkalemic (serum potassium 7.3 mEq/L). Within hours of presentation she suffered a ventricular fibrillation arrest, followed by a terminal asystolic arrest. Postmortem analyses of liver tissue and the seeds were consistent with fatal T. peruviana poisoning. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: T. peruviana seeds contain toxic cardioactive steroids; their physical resemblance to candlenuts poses a risk of potentially fatal substitution. Therapy with high-dose digoxin specific immune fragments (20-30 vials) may be helpful.

Persistent Hyperinsulinemia Following High-Dose Insulin Therapy: A Case Report.

INTRODUCTION: Overdoses of beta-adrenergic antagonists and calcium channel antagonists represent an uncommonly encountered but highly morbid clinical presentation. Potential therapies include fluids, calcium salts, vasopressors, intravenous lipid emulsion, methylene blue, and high-dose insulin. Although high-dose insulin is commonly used, the kinetics of insulin under these conditions are unknown. CASE REPORT: We present a case of a 51-year-old male who sustained a life-threatening overdose after ingesting approximately 40 tablets of a mixture of amlodipine 5 mg and metoprolol tartrate 25 mg. Due to severe bradycardia and hypotension, he was started on high-dose insulin (HDI) therapy; this was augmented with epinephrine. Despite the degree of his initial shock state, he ultimately recovered, and HDI was discontinued. Insulin was infused for a total of approximately 37 hours, most of which was dosed at 10 U/kg/hour; following discontinuation, serial serum insulin levels were drawn and remained at supraphysiologic levels for at least 24 hours and well above reference range for multiple days thereafter. CONCLUSION: The kinetics of insulin following discontinuation of high-dose insulin therapy are largely unknown, but supraphysiologic insulin levels persist for some time following therapy; this may allow for simple discontinuation rather than titration of insulin at the end of therapy. Dextrose replacement is frequently needed; although the duration is often difficult to predict, prolonged infusions may not be necessary.

Effect of Methylene Blue on a Porcine Model of Amlodipine Toxicity.

INTRODUCTION: Calcium channel blocker (CCB) overdoses cause significant morbidity and mortality. Dihydropyridine CCBs cause peripheral vascular dilation and at high doses cardiac dysfunction. Amlodipine, a dihydropyridine, causes peripheral vasodilation from release of nitric oxide (NO) in addition to calcium channel blockade; NO scavenging is a potential treatment. Methylene blue (MB) inhibits NO directly and inhibits NO production. We compared the effects of MB versus norepinephrine (NE), with time to death as the primary outcome, in a porcine amlodipine toxicity model. METHODS: Animals were anesthetized and instrumented, and an amlodipine infusion was administered to mimic oral overdose. After 70 minutes, each group was resuscitated with normal saline. Animals in each group were then randomized to receive either MB or NE. Hemodynamic parameters, including mean arterial pressure and cardiac output, were recorded every 10 minutes. The primary outcome was survival time (Kaplan-Meier analysis and log-rank test). RESULTS: Interim analysis after 15 animals (7 MB, 8 NE) revealed that MB was clearly not superior to NE. Overall, 1 of 7 animals in the MB group survived to 300 minutes compared with 2 of 8 animals in the NE group. The median survival time was 100 minutes for the MB group and 177 minutes for the NE group. Survival time did not differ by group (log-rank test p = 0.29). CONCLUSION: In this porcine model of amlodipine toxicity, methylene blue did not improve survival time compared with norepinephrine. Whether methylene blue is beneficial in combatting distributive shock in amlodipine toxicity remains unclear and requires further study.

Use of a Porcine Model to Evaluate the Risks and Benefits of Vasopressors in Propranolol Poisoning.

INTRODUCTION: Vasopressors are a commonly used treatment in beta-blocker poisoning despite evidence they may be ineffective or harmful. The primary objective of the present study is to use previously collected data from two prior studies (high-dose insulin (HDI) versus vasopressin + epinephrine and a placebo-controlled HDI study) to compare survival between vasopressin + epinephrine and placebo. Secondary outcomes included a comparison with HDI as well as comparisons with hemodynamic parameters, including mean arterial pressure (MAP), cardiac output (CO), heart rate (HR), and systemic vascular resistance (SVR). METHODS: Cardiogenic shock was induced in healthy pigs with a bolus of 0.5 mg/kg of intravenous propranolol followed by an infusion of 0.25 mg/kg/minute until the point of toxicity, defined as (0.75 × initial HR × initial MAP), at which point the infusion was reduced to 0.125 mg/kg/minute for 240 (vasopressin + epinephrine or HDI) or 360 minutes (placebo) or until death. RESULTS: Survival was significantly lower in pigs receiving vasopressin + epinephrine (0%, 0/5) than in pigs receiving placebo (50%, 2/4) (p < 0.01). Survival was significantly higher with HDI compared with both groups (100%, 5/5) (p < 0.01). All vasopressin + epinephrine pigs died within 100 minutes after reaching toxicity. Over the course of the resuscitation, we observed a statistically significant steady decrease in CO and HR in the vasopressin + epinephrine group compared with placebo (p < 0.01). In contrast, we observed a statistically significant change in MAP and SVR that followed a parabolic arc, with MAP and SVR rising significantly initially in the vasopressin + epinephrine group then rapidly falling until death (p < 0.01). CONCLUSIONS: Mortality was higher with vasopressors compared with placebo in this porcine model of propranolol poisoning. Further studies are warranted to define the optimal timing and role of vasopressors in beta-blocker poisoning.