Glucagon in β‐Blocker and Calcium Channel Blocker Overdoses: A Systematic Review

Hepatic glucagon action: beyond glucose mobilization

Glucagon's ability to promote hepatic glucose production has been known for over a century, with initial observations touting this hormone as a diabetogenic agent. However, glucagon receptor agonism [when balanced with an incretin, including glucagon-like peptide 1 (GLP-1) to dampen glucose excursions] is now being developed as a promising therapeutic target in the treatment of metabolic diseases, like metabolic dysfunction-associated steatotic disease/metabolic dysfunction-associated steatohepatitis (MASLD/MASH), and may also have benefit for obesity and chronic kidney disease. Conventionally regarded as the opposing tag-team partner of the anabolic mediator insulin, glucagon is gradually emerging as more than just a "catabolic hormone." Glucagon action on glucose homeostasis within the liver has been well characterized. However, growing evidence, in part thanks to new and sensitive "omics" technologies, has implicated glucagon as more than just a "glucose liberator." Elucidation of glucagon's capacity to increase fatty acid oxidation while attenuating endogenous lipid synthesis speaks to the dichotomous nature of the hormone. Furthermore, glucagon action is not limited to just glucose homeostasis and lipid metabolism, as traditionally reported. Glucagon plays key regulatory roles in hepatic amino acid and ketone body metabolism, as well as mitochondrial turnover and function, indicating broader glucagon signaling consequences for metabolic homeostasis mediated by the liver. Here we examine the broadening role of glucagon signaling within the hepatocyte and question the current dogma, to appreciate glucagon as more than just that "catabolic hormone."

The pancreas does not contribute to the non-adrenergic-non-cholinergic stimulation of heart rate in digesting pythons

Vertebrates elevate heart rate when metabolism increases during digestion. Part of this tachycardia is due to a non-adrenergic-non-cholinergic (NANC) stimulation of the cardiac pacemaker, and it has been suggested these NANC factors are circulating hormones that are released from either gastrointestinal or endocrine glands. The NANC stimulation is particularly pronounced in species with large metabolic responses to digestion, such as reptiles. To investigate the possibility that the pancreas may release hormones that exert positive chronotropic effects on the digesting Burmese python heart, a species with very large postprandial changes in heart rate and oxygen uptake, we evaluate how pancreatectomy affects postprandial heart rate before and after autonomic blockade of the muscarinic and the beta-adrenergic receptors. We also measured the rates of oxygen consumption and evaluated the short-term control of the heart using the spectral analysis of heart rate variability and the baroreflex sequence method. Digestion caused the ubiquitous tachycardia, but the intrinsic heart rate (revealed after the combination of atropine and propranolol) was not affected by pancreatectomy and therefore hormones, such as glucagon and insulin, do not appear to contribute to the regulation of heart rate during digestion in Burmese pythons.

Beta-blocker and calcium-channel blocker toxicity: current evidence on evaluation and management

Beta-blocker and calcium-channel blocker overdoses are associated with severe morbidity and mortality; therefore, it is important to recognize and appropriately treat individuals with toxicity. The most common clinical findings in toxicity are bradycardia and hypotension. In addition to supportive care and cardiac monitoring, specific treatment includes administration of calcium salts, vasopressors, and high-dose insulin euglycaemia treatment. Other advanced treatments (e.g. ECMO) may be indicated depending on the severity of toxicity and specific agents involved.

Synthesis of Dihydropyrimidines: Isosteres of Nifedipine and Evaluation of Their Calcium Channel Blocking Efficiency

Hypertension and cardiovascular diseases related to it remain the leading medical challenges globally. Several drugs have been synthesized and commercialized to manage hypertension. Some of these drugs have a dihydropyrimidine skeleton structure, act as efficient calcium channel blockers, and affect the calcium ions' intake in vascular smooth muscle, hence managing hypertension. The synthesis of such moieties is crucial, and documenting their structure-activity relationship, their evolved and advanced synthetic procedures, and future opportunities in this area is currently a priority. Tremendous efforts have been made after the discovery of the Biginelli condensation reaction in the synthesis of dihydropyrimidines. From the specific selection of Biginelli adducts to the variation in the formed intermediates to achieve target compounds containing heterocylic rings, aldehydes, a variety of ketones, halogens, and many other desired functionalities, extensive studies have been carried out. Several substitutions at the C3, C4, and C5 positions of dihydropyrimidines have been explored, aiming to produce feasible derivatives with acceptable yields as well as antihypertensive activity. The current review aims to cover this requirement in detail.

Cardiovascular and Adverse Effects of Glucagon for the Management of Suspected Beta Blocker Toxicity: a Case Series

BACKGROUND

Although glucagon use in beta blocker toxicity has been recommended for many years, evidence for its safety and efficacy in humans is limited. This study aims to determine the magnitude of effect of glucagon on heart rate (HR) and systolic blood pressure (SBP) in patients with suspected beta blocker toxicity and describe potential adverse effects of the medication.

METHODS

We conducted a retrospective, multi-center case series of patients greater than 12 years of age who received glucagon for suspected beta blocker toxicity. The primary outcome was the mean difference in HR from immediately pre- to 20-minutes post-glucagon administration. Secondary outcomes included the median difference in SBP, and occurrence of nausea, vomiting, and hyperglycemia.

RESULTS

A total of 107 patients met inclusion criteria accounting for 144 glucagon orders. The mean difference in HR from pre- to post-glucagon administration was 4 bpm ± 10.6 (95% CI [2.25-5.76], p < 0.001). The median difference (IQR) in SBP was 4.5 (- 6 to 16) mmHg (p = 0.004). Similar increases were observed when patients receiving concomitant vasopressors were excluded. A total of nine glucagon administrations (6.3%) were associated with nausea and 14 (9.7%) with vomiting; however, 52 doses (36.1%) were administered concomitantly with antiemetic medications. Fifteen administrations (10.4%) were associated with hyperglycemia.

CONCLUSION

Glucagon administration was associated with a statistically significant increase in HR, but a small absolute difference of uncertain clinical significance. A similar observation was noted for SBP. Few patients experienced adverse events.

Nicorandil and ranolazine overdose management

A man in his 60s was admitted to the emergency department with chest pain following an intentional overdose of nicorandil and ranolazine. He was known to have an extensive cardiac history and had taken his prescribed medication with suicidal ideation. On presentation, he was hypotensive with a blood pressure of 70/50 mm Hg despite fluid resuscitation. He was commenced on vasopressor support and transferred to the intensive care unit. Despite an adequate blood pressure on vasopressors, he suffered a ventricular fibrillation cardiac arrest. Return of spontaneous circulation with a Glasgow Coma Score of 15 was achieved following cardiopulmonary resuscitation and three direct current shocks. Following subsequent continuous overnight significant vasopressor dependence, a dose of glucagon was given, and within 2 hours, his vasopressor requirement ceased, maintaining an unsupported normal blood pressure. He remained stable and was subsequently discharged to the coronary care unit for monitoring.

"Feeling the Blues": A Case of Calcium Channel Blocker Overdose Managed With Methylene Blue

Amlodipine is a dihydropyridine calcium channel blocker (CCB) commonly used to treat hypertension. In the United States, approximately 9,500 cases of CCB intoxication due to deliberate or inadvertent overdose were reported to poison centers in 2002. We present a case of a patient who presented with CCB overdose complicated by acute respiratory distress syndrome (ARDS) and recalcitrant shock all of which resolved with methylene blue therapy. We present a case of a 56-year-old African American woman who presented to the emergency department (ED) after intentional ingestion of large amounts of multiple pills likely consisting of cyclobenzaprine, amlodipine, losartan, and ibuprofen following an argument with her boyfriend. Treatment included insulin drip, 10% dextrose, and norepinephrine drip which was titrated up. First insulin drip and 10% dextrose were titrated up; however, vasopressor-resistant hypotension persisted, and the decision was made to administer methylene blue. Over 9,500 cases of CCB toxicity were reported to poison centers in the US in 2002. Although no definitive treatment is outlined, first-line therapy consists of IV calcium, high-dose insulin, and vasopressor support with either norepinephrine or epinephrine. Traditionally, methylene blue is used for methemoglobinemia and in cardiothoracic ICUs for post coronary artery bypass vasoplegia. It acts by selectively inhibiting nitric oxide-activated cyclic guanylate cyclase leading to decreased vasodilation of arteriolar smooth muscles improving vascular tone and systemic vascular resistance. In severe amlodipine overdose, experimental models demonstrate methylene blue improves HR and mean arterial pressure (MAP), improving survival rate. With few adverse side effects (green-tinged discoloration of urine, saliva, tears, and bodily fluids), methylene blue should be explored and implemented in the treatment of CCB overdose with refractory hypotension and ARDS.

Causes, Predisposing Factors and Prevention Directions of Drug-induced Bradycardia (Based on the Results of the Hospital Register of Oardiac Medications Overdoses STORM)

Aim. Analysis of drug-induced bradiarrhythmia (DIB) causes and predisposing factors, followed by the development of recommendations for practitioners on its prevention.

Material and methods. The register included consistently all cases of hospitalization at the Regional Vascular Center (Ryazan) due to DIB in 2017 (n=114), 2018 (n=167), and retrospectively in 2014 (n=44). In total, 325 cases were reported: men - 26.1%, age 76.0 [68.0; 82.0] years; patients >65 years - 83.7%, and patients >75 years - 57.9%. The dose of medications with bradycardic action (BCA) taken the day before was known in 227 cases (69.8%), which allowed us to analyze the correctness of the intake regime in these cases.

Results. The excess of a single and / or daily medication dose (absolute overdose, AOD) occurred only in 10.6% of cases and was associated with the patient's attempt to cope with the deterioration of the disease or an acute clinical situation on their own. In other cases, there was no formal violation of the Instructions, but there was an inhibition of the heart's conducting system activity, characteristic of an overdose of medication (the so-called "relative” overdose, ROD). It was due to the summation/potentiation of BCA of several medications or changes in the medication pharmacokinetics. There were no differences in the clinical and demographic characteristics of patients and the provision of medical care in the groups with AOD and ROD (p>0.05). The exception was a high frequency of bradycardia <40 beats / min in AOD group (75.0% vs 49.8%, p=0.019) and, as a result, - management in the conditions of the Intensive Care Unit (66.7% vs 39.9%, p=0.012). Frequency of pre-admission receiving medications in AOD and ROD groups also did not differ (p>0.05): beta-blockers - an average of 64.3%, antiarrhythmic drugs with BCA- 41.0%, cardiac glycosides 25.1% (frequency each of these medicationsin DIB cases over the 5-year period has not changed), an agonist of the 11-imidazoline receptors - moxonidine (12.3%, its frequency has increased 8.9 times in 5 years, p=0.004), non-dihydropyridine calcium antagonists - 7.9% (decrease frequency over 5 years 4.0 times, p=0.002), other - 16.7%. In 56.8% of cases, medications with BCA were used in combination. At admission, a decrease in glomerular filtration rate (GFR) <45 ml/min/1.73 m2 was registered in 56.8% of cases, <30 ml/min/1.73 m2 - in 31.8%, <15 ml/min/1.73 m2 -in 10.9% (differences between groups with p>0.05). Hospital lethality in the AOD group is 4.2%, in the ROD group- 5.4% (p>0.05).

Conclusion. The main reasons of DIB are excess of the recommended dose, unrecorded summation/potentiation of BCA of several medications, and / or changes in the medication pharmacokinetics. Predisposing factors are self-medication of patients with worsening cardiovascular disease or acute clinical situations (e.g., hypertensive crisis), taking multiple medications with BCA, accession of heart disease, manifested by bradyarrhythmia, decrease in GFR, elderly and senile age.

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

Bradyarrhythmias and Physiologic Pacing in the ICU

Bradyarrhythmias represent a common pathology in the intensive care unit (ICU) with etiologies of varying severity. Treatment has often been focused on correcting underlying causes and may require pacing for urgent hemodynamic support. In recent years, there has been interest in physiologic pacing modalities which avoid the dyssynchrony from right ventricular (RV) only pacing. Cardiac resynchronization therapy (CRT) through biventricular pacing is a well-established device-based electrical therapy in patients with wide QRS and heart failure. Recently, it has been shown that biventricular pacing may also be pursued for hemodynamic rescue in the ICU setting. Efforts to re-engage the conduction system with His bundle pacing or further downstream have also emerged as alternative means to deliver resynchronization, with early applications in the ICU now being reported. The goal of the review is to examine bradyarrhythmia causes and management in the ICU as well as investigate new approaches in physiologic pacing and their potential roles in critically ill patients.

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

High-Dose Glucagon Has Hemodynamic Effects Regardless of Cardiac Beta-Adrenoceptor Blockade: A Randomized Clinical Trial

Background Intravenous high-dose glucagon is a recommended antidote against beta-blocker poisonings, but clinical effects are unclear. We therefore investigated hemodynamic effects and safety of high-dose glucagon with and without concomitant beta-blockade. Methods and Results In a randomized crossover study, 10 healthy men received combinations of esmolol (1.25 mg/kg bolus+0.75 mg/kg/min infusion), glucagon (50 µg/kg), and identical volumes of saline placebo on 5 separate days in random order (saline+saline; esmolol+saline; esmolol+glucagon bolus; saline+glucagon infusion; saline+glucagon bolus). On individual days, esmolol/saline was infused from -15 to 30 minutes. Glucagon/saline was administered from 0 minutes as a 2-minute intravenous bolus or as a 30-minute infusion (same total glucagon dose). End points were hemodynamic and adverse effects of glucagon compared with saline. Compared with saline, glucagon bolus increased mean heart rate by 13.0 beats per minute (95% CI, 8.0-18.0; P<0.001), systolic blood pressure by 15.6 mm Hg (95% CI, 8.0-23.2; P=0.002), diastolic blood pressure by 9.4 mm Hg (95% CI, 6.3-12.6; P<0.001), and cardiac output by 18.0 % (95% CI, 9.7-26.9; P=0.003) at the 5-minute time point on days without beta-blockade. Similar effects of glucagon bolus occurred on days with beta-blockade and between 15 and 30 minutes during infusion. Hemodynamic effects of glucagon thus reflected pharmacologic glucagon plasma concentrations. Glucagon-induced nausea occurred in 80% of participants despite ondansetron pretreatment. Conclusions High-dose glucagon boluses had significant hemodynamic effects regardless of beta-blockade. A glucagon infusion had comparable and apparently longer-lasting effects compared with bolus, indicating that infusion may be preferable to bolus injections. Registration Information URL: https://www.clinicaltrials.gov; Unique identifier: NCT03533179.

Propafenone and propranolol dual toxicity

Propranolol is a highly lipid-soluble beta-receptor antagonist and propafenone is a potent class 1c anti-arrhythmic agent with strong Na-channel blockade effect. We describe a novel case of dual overdose of propafenone and propranolol resulting in hypotension, generalized seizures, and reduced level of consciousness that was successfully treated. A 52-year-old female ingested 500 mg of propranolol and 1.5 g of propafenone. The patient was brought to the emergency department (ED) and exhibited signs of systemic toxicity and reduced level of consciousness. The patient was treated as a case of combined β-blocker and propafenone toxicity using high dose insulin, NaHCO3, glucagon, atropine, and dopamine. She started improving and becoming more alert, with subsequent ECGs revealing normal sinus rhythm. The patient was discharged 4 days later. We believe that early administration of NaHCO3 should be administered in patients exhibiting signs of Na-channel blockade.

Extracorporeal Membrane Oxygenation for Poisonings Reported to U.S. Poison Centers from 2000 to 2018: An Analysis of the National Poison Data System

OBJECTIVES

To assess trends in the use of extracorporeal membrane oxygenation for poisoning in the United States.

DESIGN

Retrospective cohort study.

SETTING

The National Poison Data System, the databased owned and managed by the American Association of Poison Control Centers, the organization that supports and accredits all 55 U.S. Poison Centers, 2000-2018.

PATIENTS

All patients reported to National Poison Data System treated with extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In total, 407 patients met final inclusion criteria (332 adults, 75 children). Median age was 27 years (interquartile range, 15-39 yr); 52.5% were male. Median number of ingested substances was three (interquartile range, 2-4); 51.5% were single-substance exposures. Extracorporeal membrane oxygenation use in poisoned patients in the United States has significantly increased over time (z = 3.18; p = 0.001) in both adults (age > 12 yr) and children (age ≤ 12 yr), increasing by 9-100% per year since 2008. Increase in use occurred more commonly in adults. We found substantial geographical variation in extracorporeal membrane oxygenation use by geospatially mapping the ZIP code associated with the initial call, with large, primarily rural areas of the United States reporting no cases. Overall survival was 70% and did not vary significantly over the study period for children or adults. Patients with metabolic and hematologic poisonings were less likely to survive following extracorporeal membrane oxygenation than those with other poisonings (49% vs 72%; p = 0.004).

CONCLUSIONS

The use of extracorporeal membrane oxygenation to support critically ill, poisoned patients in the United States is increasing, driven primarily by increased use in patients greater than 12 years old. We observed no trends in survival over time. Mortality was higher when extracorporeal membrane oxygenation was used for metabolic or hematologic poisonings. Large, predominantly rural regions of the United States reported no cases of extracorporeal membrane oxygenation for poisoning. Further research should focus on refining criteria for the use of extracorporeal membrane oxygenation in poisoning.

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.

Hyponatremia induced by hyperinsulinemia-euglycemia therapy

PURPOSE

A case of symptomatic hyponatremia induced by hyperinsulinemia-euglycemia (HIE) therapy is reported.

SUMMARY

A 59-year-old, 81.65-kg woman with hypertension, major depressive disorder, and anxiety arrived at a tertiary medical center 1.5 hours after an intentional overdose of oral amlodipine 200 mg, metoprolol tartrate 2,000 mg, and isosorbide mononitrate 1,200 mg. Upon arrival, her pulse was 63 beats/min and blood pressure was 106/56 mm Hg. The patient's blood pressure was refractory to fluids, calcium gluconate, and norepinephrine, resulting in initiation of HIE therapy. She had recurrent episodes of hypoglycemia, which required increases of the dextrose infusion and resulted in the patient receiving a total of 6.9 L of dextrose with free water. Seventeen hours into the hospitalization, the patient became obtunded due to hyponatremia (serum sodium concentration, 121 mmol/L). HIE therapy was discontinued, an infusion of 5% dextrose injection with sodium bicarbonate added was started, and a bolus of 3% sodium chloride was administered. Nine hours after the presentation of hyponatremia, the patient's serum sodium concentration normalized (137 mmol/L), and her symptoms resolved. The patient's blood pressure, pulse, and mental status continued to improve, and the patient was transferred out of the medical intensive care unit 41 hours after her arrival at the hospital.

CONCLUSION

A woman who overdosed on amlodipine, metoprolol tartrate, and isosorbide mononitrate was treated with HIE therapy and developed symptomatic hyponatremia. Hyponatremia resolved after administration of dextrose with sodium bicarbonate infusion and 3% sodium chloride infusion and cessation of HIE therapy.

Clinical toxicology of beta-blocker overdose in adults

Beta-blocker overdose is potentially harmful due to the strong blood pressure-lowering and heart rate-lowering effects. However, conflicting data exist as to their differential toxicity, single-substance exposures and the effect of co-exposure with additional antihypertensive medication. For this, a 10-year retrospective, explorative analysis of the Mainz Poison Center/Germany database with regard to circumstances of beta-blocker exposure, doses, symptoms and treatment was carried out. Analyses were restricted to adult patients with single-substance exposures and co-exposures with one additional antihypertensive substance. Written follow-up information was obtained in half the cases. A total of 2967 cases were analysed, of which 697 were single-substance exposures. Metoprolol was most frequently reported followed by bisoprolol, atenolol, propranolol and sotalol. Metoprolol showed a linear dose-symptom relationship, whereas propranolol and sotalol seemed to have a threshold dose beyond which symptoms aggravated. Symptoms did not differ substantially, except for more seizures being reported with propranolol, and more CNS depression/vomiting with sotalol. Activated charcoal was used in 38%, gastric lavage in 11%, temporary pacemaker in 3%, glucagon in 1%, intubation for respiratory insufficiency and cardiopulmonary resuscitation in 1% and 0.5%. All patients recovered. In 174 co-exposure cases, the distribution of poisoning severity and rate of worsening of symptoms was comparable with single-substance exposures except one patient deceased after bisoprolol and verapamil co-exposure. In adults with beta-blocker overdose, no significant differences in poisoning severity among beta-blockers were detected, and no fatalities were observed with single-substance exposures. Co-exposures with other antihypertensives, sedatives or alcohol should be carefully attended to as fatalities might occur.

Hemodynamic Effects of Glucagon: A Literature Review

CONTEXT

Glucagon's effects on hemodynamic parameters, most notably heart rate and cardiac contractility, are often overlooked. The glucagon receptor is a central target in novel and anticipated type 2 diabetes therapies, and hemodynamic consequences of glucagon signaling have therefore become increasingly important. In this review, we summarize and evaluate published studies on glucagon pharmacology with a focus on clinical hemodynamic effects in humans.

EVIDENCE ACQUISITION

PubMed, Embase, and the Cochrane Library were searched for clinical studies concerning hemodynamic effects of glucagon (no year restriction). Papers reporting effects of a defined glucagon dose on any hemodynamic parameter were included. Reference searches were conducted in retrieved articles.

EVIDENCE SYNTHESIS

Hemodynamic effects of glucagon have been investigated mainly in cohort studies of patients suffering from heart failure receiving large glucagon bolus injections. The identified studies had shortcomings related to restricted patient groups, lack of a control group, randomization, or blinding. We identified no properly conducted randomized clinical trials. The majority of human studies report stimulating effects of pharmacological glucagon doses on heart rate, cardiac contractility, and blood pressure. The effects were characterized by short duration, interindividual variation, and rapid desensitization. Some studies reported no measurable effects of glucagon.

CONCLUSIONS

The level of evidence regarding hemodynamic effects of glucagon is low, and observations in published studies are inconsistent. Actual effects, interindividual variation, dose-response relationships, and possible long-term effects of supraphysiological glucagon levels warrant further investigation.

The Use of Glucagon and other Antidotes in a Case of Beta-Blocker and Calcium Channel Blocker Overdose

We report a case of metoprolol and nifedipine overdose complicated by hypotension which responded to intravenous boluses of calcium chloride and glucagon. The blood pressure was subsequently stabilised by continuous glucagon infusion with the aid of an insulin-dextrose drip. The discussion is focused on the role of antidotes and catecholamine inotropes in the management of beta-blocker and calcium channel blocker poisoning.

Severe carvedilol toxicity without overdose - caution in cirrhosis

Background

Carvedilol is used in the management of hypertension, ischemic heart disease, heart failure and most recently, portal hypertension. It has been associated with improved outcomes regarding variceal bleeding, hepatic decompensation and death when compared to propranolol and endoscopic band ligation. The main cause of portal hypertension is cirrhosis and therefore carvedilol is increasingly used in these patients. Due to its extensive hepatic metabolism, carvedilol is contraindicated in severe hepatic impairment. However, there are no dosage adjustments in the manufacturer's labelling for mild to moderate hepatic impairment.

Case presentation

We present a case of cardiogenic shock that occurred after carvedilol 25 mg orally was administered to a patient with cirrhosis. As there was no overdose, the diagnosis was based on clinical recognition of the toxidrome. The patient was successfully treated with glucagon 5 mg bolus followed by infusion.

Conclusions

Patients with cirrhosis represent a special at-risk group for beta blocker toxicity. The typical threshold for carvedilol toxicity in overdose is 50 mg but in patients with cirrhosis this is not applicable. Nurses and physicians need to recognize the toxidrome early. Hospitals where carvedilol is used in patients with cirrhosis should have glucagon in formulary at doses to treat toxicity (bolus and infusion). Finally, dose adjustment and slow uptitration of carvedilol in cirrhosis is recommended.

Glucagon in artificial pancreas systems: Potential benefits and safety profile of future chronic use

The role of glucagon in the pathophysiology of diabetes has long been recognized, although its approved clinical use has so far been limited to the emergency treatment of severe hypoglycaemia. A novel use of glucagon as intermittent mini-boluses is proposed in the dual-hormone version (insulin and glucagon) of the external artificial pancreas. Short-term studies suggest that the incorporation of glucagon into artificial pancreas systems has the potential to further decrease hypoglycaemic risk and improve overall glucose control; however, the potential long-term safety and benefits also need to be investigated given the recognized systemic effects of glucagon. In the present report, we review the available animal and human data on the physiological functions of glucagon, as well as its pharmacological use, according to dosing and duration (acute and chronic). Along with its main role in hepatic glucose metabolism, glucagon affects the cardiovascular, renal, pulmonary and gastrointestinal systems. It has a potential role in weight reduction through its central satiety function and its role in increasing energy expenditure. Most of the pharmacological studies investigating the effects of glucagon have used doses exceeding 1 mg, in contrast to the mini-boluses used in the artificial pancreas. The available data are reassuring but comprehensive human studies using small but chronic glucagon doses that are close to the physiological ranges are lacking. We propose a list of variables that could be monitored during long-term trials of the artificial pancreas. Such trials should address the questions about the risk-benefit ratio of chronic glucagon use.

Glucagon-induced hypertensive emergency: a case report

Glucagon is well acknowledged as a sphincter of Oddi relaxant for both diagnostic and therapeutic uses in choledocholithiasis, and an empiric treatment for β-blocker overdose. Although it has been implicated in inducing cardiovascular crises in patients with asymptomatic pheochromocytoma, adverse effects in other patient populations have not been characterized. This case report describes a patient with hypertension controlled on β blockers who, after glucagon administration during an intraoperative cholangiography, experienced hypertensive emergency despite adequate pain control. Nitroglycerin acted as a key agent to decrease the patient's blood pressure as well as a secondary relaxant of the sphincter of Oddi. The patient had no radiographic evidence of pheochromocytoma. As out-of-operating room and intraoperative uses of glucagon continue to increase, perioperative physicians should be aware of its potential hemodynamic effects even in healthy populations.

Antidote Use in the Critically Ill Poisoned Patient

The proper use of antidotes in the intensive care setting when combined with appropriate general supportive care may reduce the morbidity and mortality associated with severe poisonings. The more commonly used antidotes that may be encountered in the intensive care unit ( N-acetylcysteine, ethanol, fomepizole, physostigmine, naloxone, flumazenil, sodium bicarbonate, octreotide, pyridoxine, cyanide antidote kit, pralidoxime, atropine, digoxin immune Fab, glucagon, calcium gluconate and chloride, deferoxamine, phytonadione, botulism antitoxin, methylene blue, and Crotaline snake antivenom) are reviewed. Proper indications for their use and knowledge of the possible adverse effects accompanying antidotal therapy will allow the physician to appropriately manage the severely poisoned patient.

Calcium channel antagonist and beta-blocker overdose: antidotes and adjunct therapies

Management of cardiovascular instability resulting from calcium channel antagonist (CCB) or beta-adrenergic receptor antagonist (BB) poisoning follows similar principles. Significant myocardial depression, bradycardia and hypotension result in both cases. CCBs can also produce vasodilatory shock. Additionally, CCBs, such as verapamil and diltiazem, are commonly ingested in sustained-release formulations. This can also be the case for some BBs. Peak toxicity can be delayed by several hours. Provision of early gastrointestinal decontamination with activated charcoal and whole-bowel irrigation might mitigate this. Treatment of shock requires a multimodal approach to inotropic therapy that can be guided by echocardiographic or invasive haemodynamic assessment of myocardial function. High-dose insulin euglycaemia is commonly recommended as a first-line treatment in these poisonings, to improve myocardial contractility, and should be instituted early when myocardial dysfunction is suspected. Catecholamine infusions are complementary to this therapy for both inotropic and chronotropic support. Catecholamine vasopressors and vasopressin are used in the treatment of vasodilatory shock. Optimizing serum calcium concentration can confer some benefit to improving myocardial function and vascular tone after CCB poisoning. High-dose glucagon infusions have provided moderate chronotropic and inotropic benefits in BB poisoning. Phosphodiesterase inhibitors and levosimendan have positive inotropic effects but also produce peripheral vasodilation, which can limit blood pressure improvement. In cases of severe cardiogenic shock and/or cardiac arrest post-poisoning, extracorporeal cardiac assist devices have resulted in successful recovery. Other treatments used in refractory hypotension include intravenous lipid emulsion for lipophilic CCB and BB poisoning and methylene blue for refractory vasodilatory shock.

[Cardiogenic shock after drug therapy for atrial fibrillation with tachycardia : Case report of an 89-year-old woman]

β-Blockers and calcium channel blockers are commonly used drugs in the treatment of atrial fibrillation with tachycardia. However, in patients with high myocardial susceptibility and vulnerability, combination therapy with β-blockers and non-dihydropyridine calcium channel blockers (verapamil or diltiazem) but also individual administration can cause drug-induced cardiogenic shock. Thus, the simultaneous administration of β-blockers and non-dihydropyridine calcium channel blockers is absolutely contraindicated. In case of acute heart failure, isolated application is also contraindicated. In the treatment of a cardiogenic shock induced by β-blockers and/or non-dihydropyridine calcium channel blockers, administration of intravenous calcium, glucagon or high-dose insulin is recommended.

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

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

Efficacy of methylene blue in an experimental model of calcium channel blocker-induced shock

STUDY OBJECTIVE

Calcium channel blocker poisonings account for a substantial number of reported deaths from cardiovascular drugs. Although supportive care is the mainstay of treatment, experimental therapies such as high-dose insulin-euglycemia and lipid emulsion have been studied in animal models and used in humans. In the most severe cases, even aggressive care is inadequate and deaths occur. In both experimental models and clinical cases of vasodilatory shock, methylene blue improves hemodynamic measures. It acts as a nitric oxide scavenger and inhibits guanylate cyclase that is responsible for the production of cyclic guanosine monophosphate (cGMP). Excessive cGMP production is associated with refractory vasodilatory shock in sepsis and anaphylaxis. The aim of this study is to determine the efficacy of methylene blue in an animal model of amlodipine-induced shock.

METHODS

Sprague-Dawley rats were anesthetized, ventilated, and instrumented for continuous blood pressure and pulse rate monitoring. The dose of amlodipine that produced death within 60 minutes was 17 mg/kg per hour (LD50). Rats were divided into 2 groups: amlodipine followed by methylene blue or amlodipine followed by normal saline solution, with 15 rats in each group. Rats received methylene blue at 2 mg/kg during 5 minutes or an equivalent amount of normal saline solution in 3 intervals from the start of the protocol: minutes 5, 30, and 60. The animals were observed for a total of 2 hours after the start of the protocol. Mortality risk and survival time were analyzed with Fisher's exact test and Kaplan-Meier survival analysis with the log rank test.

RESULTS

Overall, 1 of 15 rats (7%) in the saline solution-treated group survived to 120 minutes compared with 5 of 15 (33%) in the methylene blue-treated group (difference -26%; 95% confidence interval [CI] -54% to 0.3%). The median survival time for the normal saline solution group was 42 minutes (95% CI 28.1 to 55.9 minutes); for the methylene blue group, 109 minutes (95% CI 93.9 to 124.1 minutes). Pulse rate and mean arterial pressure (MAP) differences between groups were analyzed until 60 minutes. Pulse rate was significantly higher in the methylene blue-treated group beginning 25 minutes after the start of the amlodipine infusion (95% CI 30 to 113 minutes) that was analyzed until 60 minutes. MAP was significantly higher in the methylene blue-treated group starting 25 minutes after the amlodipine infusion (95% CI 2 to 30 minutes) that was analyzed until 60 minutes.

CONCLUSION

Methylene blue did not result in a significant difference in mortality risk. There was an increased pulse rate, MAP, and median survival time in the methylene blue group.

Management of calcium channel blocker overdoses

Calcium channel blockers (CCBs) are some of the most commonly used medications in clinical practice to treat hypertension, angina, cardiac arrhythmias, and some cases of heart failure. Recent data show that CCBs are the most common of the cardiovascular medications noted in intentional or unintentional overdoses.(1) Novel treatment approaches in the form of glucagon, high-dose insulin therapy, and intravenous lipid emulsion therapies have been tried and have been successful. However, the evidence for these are limited to case reports and case series. We take this opportunity to review the various treatment options in the management of CCB overdoses with a special focus on high-dose insulin therapy as the emerging choice for initial therapy in severe overdoses.

Atenolol and amlodipine combination overdose managed with continuous venovenous hemodiafiltration: A case report

We present a patient of who ingested large dose of of atenolol and amlodipine and was treated successfully with continuous venovenous hemodiafiltration. Early recognition of indications for renal support and early initiation of the same is the key to successful management.

Extracorporeal life support and plasmapheresis in a case of severe polyintoxication

BACKGROUND

Resuscitation without return to spontaneous circulation in patients with suicidal ingestion of cardiotoxic drugs necessitates alternative bridging therapies for drug removal.

OBJECTIVES

To show the effectiveness of emergency extracorporeal membrane oxygenation (ECMO) and plasmaspheresis in severe polyintoxication.

CASE REPORT

A 21-year-old woman developed asystole after suicidal polyintoxication with 1.75 g carvedilol, 300 mg amlodipine, 6 g amitriptyline, 500 mg torsemide, 1.5 g ketoprofen, 28 g nicotinic acid, and 16 g gabapentin. After 3 h of cardiopulmonary resuscitation without return to spontaneous circulation, ECMO was used as a bridging therapy and a temporary pacemaker was inserted. Plasma peak levels were measured for amlodipine (29.3 μg/L), amitriptyline (1456 μg/L), carvedilol (585 μg/L), and gabapentin (126.8 mg/L). To facilitate drug removal, therapeutic plasma exchange was performed. The patient could be weaned from ECMO at day 4 and extubated on day 8 after admission without neurologic sequelae.

CONCLUSION

ECMO and plasma exchange should be considered as a therapeutic option in selected patients under resuscitation without return to spontaneous circulation after severe intoxication.

Management of a mixed overdose of calcium channel blockers, β-blockers and statins

We describe a case of extreme mixed overdose of calcium channel blockers, β-blockers and statins. The patient was successfully treated with aggressive resuscitation including cardiac pacing and multiorgan support, glucagon and high-dose insulin for toxicity related to calcium channel blockade and β-blockade, and ubiquinone for treating severe presumed statin-induced rhabdomyolysis and muscle weakness.

Hemodynamically unstable: accidental atenolol toxicity?

BACKGROUND

Antihypertensive medications, including β-blockers, are widely used in patients with chronic kidney disease. Unlike most β-blockers, atenolol is excreted primarily by the kidney, and its clearance by peritoneal dialysis is poor. These pharmacokinetic factors may predispose patients to gradual accumulation of the drug over time.

OBJECTIVES

To review the management of a diagnostic dilemma, the role of glucagon therapy, and the clinical implications of atenolol clearance.

CASE REPORT

A young woman with end-stage renal disease requiring peritoneal dialysis presented with sudden onset of abdominal pain and hemodynamic instability with hypotension and relative bradycardia. The patient reported that she took her regular four antihypertensive agents, including atenolol, with no excess ingestion or recent dose changes. After resuscitation and consideration of a broad differential diagnosis, the most likely cause of the patient's illness was determined to be unintentional atenolol toxicity, with secondary mesenteric ischemia due to a low-flow state that caused her abdominal pain. Glucagon therapy led to rapid correction of the patient's hemodynamic instability and pain.

CONCLUSION

The unique pharmacokinetics of long-term medications must be considered in patients with impaired clearance, such as this patient with end-stage renal disease treated by peritoneal dialysis. Medications may gradually accumulate to supratherapeutic levels, which over time may lead to symptoms of significant toxicity.

Levosimendan Does Not Improve Cardiac Output or Blood Pressure in a Rodent Model of Propranolol Toxicity When Administered Using Various Dosing Regimens

Background: Levosimendan (CAS: 141505-33-1) is a myocardial calcium sensitizer that improves myocardial contractility in various forms of heart failure. It produces a moderate improvement in cardiac output (CO) without an improvement in blood pressure (BP) in verapamil and metoprolol poisoned rodents. Aim: To assess the effect of various levosimendan dosing regimens on hemodynamics in a rodent model of propranolol poisoning. Method: Male Wistar rats (350-450 g) were anesthetized, ventilated, and instrumented to record BP, heart rate (HR), and CO. Propranolol was infused continually. When BP dropped to 50% of baseline rats received 1 of 7 treatments: (1) 0.9% saline (control), (2) levosimendan 36 μg/kg loading dose then 0.6 μg/kg per min, (3) levosimendan 0.6 μg/kg per min, (4) epinephrine 0.5 μg/kg per min, (5) levosimendan 70 μg/kg loading dose then 1.2 μg/kg per min, (6) levosimendan 1.2 μg/kg per min, and (7) levosimendan 70 μg/kg loading dose alone. Hemodynamics were recorded every 10 minutes for 70 minutes. Cardiac output, mean arterial pressure, and HR for each group were compared with control. Results: All groups had comparable baseline and maximal toxicity hemodynamics prior to initiation of treatment. Levosimendan did not improve CO or BP with any dosing regimen. Blood pressure tended to be lower than control for all doses of levosimendan. Epinephrine significantly improved BP but not CO compared to all other treatment groups. Survival did not differ between groups. Conclusions: Unlike in verapamil and metoprolol poisoning models, levosimendan did not improve CO or survival in propranolol poisoning. Epinephrine improved BP, but not CO, suggesting that its actions were due to peripheral vasoconstriction.

Levosimendan infusion improves cardiac output but not blood pressure in a rodent model of severe metoprolol toxicity

Levosimendan (Levo) is an inodilator improving cardiac output (CO) and reducing afterload in heart failure. Previously, we reported that Levo improved CO but not blood pressure (BP) in a rodent model of verapamil poisoning. We theorised that Levo-induced vasodilation should not influence BP to a similar degree in metoprolol poisoning. Aim: To assess the effect of Levo on haemodynamics in a rodent model of metoprolol poisoning. Method: Anaesthetized male Wistar rats were infused metoprolol continuously. When the BP dropped to 50% of baseline (time 0) rats received 1 of the 4 treatments: (a) control (0.9% saline bolus + infusion); (b) Levo-l (Levo 36 μm/kg loading dose followed by 0.6 μm/kg/min); (c) Levo-I (Levo infusion only at 0.6 μm/kg/min); and (d) Epi (epinephrine 0.5 μm/kg/min). All groups received comparable fluid volumes. Haemodynamics were recorded every 10 min for 70 min. CO, mean arterial pressure (MAP) and heart rate (HR) of each group were compared to the control. Results: All groups had comparable baseline and time 0 HR, MAP and CO. Levo-L and Levo-I rats showed significantly greater CO at t = 10 min ( p > 0.02 and p > 0.04, respectively). CO was higher at all other time points for both Levo groups. This was not statistically significant. Levo did not improve MAP compared to control. Adrenaline increased MAP but not CO compared to control and Levo groups. Conclusion: Levo did not improve MAP but moderately improved CO compared to control in this model of metoprolol poisoning. The response was similar to that reported previously in verapamil-poisoned rats. The improvement in MAP seen with epinephrine was most likely vasoconstriction mediated.