Calcium channel blocker toxicity

Intravenous Lipid Emulsion Treatment for Calcium-Channel Blocker Intoxication: Pediatric Case Series and Review of the Literature

BACKGROUND

Calcium-channel blocker (CCBs) intoxication remains the most lethal among all other drug overdoses (Arroyo and Kao. Pediatr Emerg Care 2009;25:533-538). This study aimed to describe the use and efficacy of intravenous lipid emulsion treatment in our CCB overdose patients in tandem with a comprehensive literature investigation.

CASE REPORTS

Hereby we report 4 adolescent patients who arrived to the pediatric emergency department after intentional CCB ingestions. All patients were hospitalized in pediatric intensive care unit because of hypotension, and they were initially treated with fluid boluses, glucagon, calcium infusion, vasopressors, inotropes and insulin. Intravenous lipid emulsion (dose: 20% lipid emulsion given as a 1.5-mL/kg bolus followed by 0.25-0.5 mL/kg/min for 30-60 minutes) treatment was given to all patients unresponsive to initial treatments. Hemodynamic instability improved immediately after intravenous lipid emulsion treatment. All patients were discharged with complete recovery at the sixth day of pediatric intensive care unit admission.

CONCLUSIONS

Intravenous lipid emulsion therapy stands as a salvage treatment for CCB intoxications with cardiovascular failure unresponsive to standard supportive treatments.

Evaluation of high-dose insulin/euglycemia therapy for suspected β-blocker or calcium channel blocker overdose following guideline implementation

PURPOSE

High-dose insulin/euglycemia (HDIE) is targeted therapy for β-blocker and calcium channel blocker overdose. A guideline using concentrated insulin infusions (20 units/mL), aggressive monitoring, and supportive recommendations was implemented. We sought to evaluate safety before and after HDIE guideline implementation and describe the patient population, insulin doses, supplemental dextrose, vasopressor use, hospital and intensive care unit (ICU) lengths of stay, and mortality.

METHODS

Retrospective review was performed of patients receiving HDIE before and after guideline implementation at an academic medical center and community hospital from March 2011 through December 2019. Information on patient and overdose demographics, ingestion data, vital signs, interventions, adverse events, and disposition was collected. Data are presented descriptively with comparisons using Mann-Whitney U analysis and Fisher's exact tests.

RESULTS

During the study period, 27 patients were treated with HDIE, 10 before guideline implementation (37%; mean [SD] initial insulin dose, 0.49 [0.35] units/kg/h; mean [SD] maximum insulin dose, 2.25 [3.29] units/kg/h; median [interquartile range] duration, 10 [5.5-18.75] hours) and 17 after guideline implementation (63%; mean [SD] initial insulin dose, 1.01 [0.34] units/kg/h; mean [SD] maximum insulin dose, 2.99 [5.05] unit/kg/h; median [interquartile range] duration, 16 [11.5-37] hours). Hypoglycemia, hypokalemia, and volume overload occurred in 80% vs 29% (P = 0.018), 40% vs 53% (P = 0.69), and 50% vs 65% (P = 0.69) of patients in the preguideline vs postguideline group, respectively. Most patients received an initial insulin bolus (85%; mean [SD], 70.3 [21.8] units, 0.9 [0.26] units/kg) and vasopressor infusion (85%). More postguideline patients received a dextrose infusion with a concentration of 20% or higher (93% vs 50%, P = 0.015). There were no differences in cardiac arrest, in-hospital mortality, or hospital or ICU length of stay between the groups.

CONCLUSION

Hypoglycemia was reduced using an HDIE guideline and concentrated insulin.

Calcium Channel Blocker Intoxication: A Critical Care Transport Perspective

Calcium channel blockers (CCBs) have seen an increase in rate of non-therapeutic exposure that is both accidental and intentional in nature. Patients experiencing the toxic effects of a CCB overdose are resource intensive and can quickly outstrip the capabilities of local health systems, necessitating transfer to larger tertiary or quaternary care centers. We present a case of intentional non-dihydropyridine CCB overdose and toxicity in a 20-year-old patient requiring initial stabilization at a referring critical access emergency department with continuation of treatment and support during a 60-minute rotor wing transport from the referring hospital to an academic quaternary care center. Emphasis is placed on the unique challenges in resuscitation and ongoing critical care administration during the transport phase of care. Proper stabilization of patients, planning, and consideration of potential problems associated with transport can help minimize stresses and risk of the transport, improving the outcome of extremely ill patients even under challenging circumstances.

Nifedipine toxicity is exacerbated by acetyl l-carnitine but alleviated by low-dose ketamine in zebrafish in vivo

Calcium channel blocker (CCB) poisoning is a common and sometimes life-threatening emergency. Our previous studies have shown that acetyl l-carnitine (ALCAR) prevents cardiotoxicity and developmental toxicity induced by verapamil, a CCB used to treat patients with hypertension. Here, we tested whether toxicities of nifedipine, a dihydropyridine CCB used to treat hypertension, can also be mitigated by co-treatment with ALCAR. In the zebrafish embryos at three different developmental stages, nifedipine induced developmental toxicity with pericardial sac edema in a dose-dependent manner, which were surprisingly exacerbated with ALCAR co-treatment. Even with low-dose nifedipine (5 μm), when the pericardial sac looked normal, ALCAR co-treatment showed pericardial sac edema. We hypothesized that toxicity by nifedipine, a vasodilator, may be prevented by ketamine, a known vasoconstrictor. Nifedipine toxicity in the embryos was effectively prevented by co-treatment with low (subanesthetic) doses (25-100 μm added to the water) of ketamine, although a high dose of ketamine (2 mm added to the water) partially prevented the toxicity.As expected of a CCB, nifedipine either in the presence or absence of ketamine-reduced metabolic reactive oxygen species (ROS), a downstream product of calcium signaling, in the rapidly developing digestive system. However, nifedipine induced ROS in the trunk region that showed significantly stunted growth indicating that the tissues under stress potentially produced pathologic ROS. To the best of our knowledge, these studies for the first time show that nifedipine and the dietary supplement ALCAR together induce adverse effects while providing evidence on the therapeutic efficacy of subanesthetic doses of ketamine against nifedipine toxicity in vivo.

Management of Calcium Channel Blocker Toxicity in the Pediatric Patient

Calcium channel blockers (CCBs) are commonly prescribed cardiovascular medications used in several disease states including hypertension, coronary artery disease, and atrial fibrillation. Inadvertent exposure or intentional overdose of CCBs may result in hypotension, bradycardia, dysrhythmias, conduction disturbances, and hyperglycemia. In the most severe cases, CCB toxicity can lead to rapid cardiovascular collapse. Given the risk of significant morbidity and mortality associated with CCB toxicity, it is important that health care professionals are able to recognize and treat patients who present with a potentially toxic ingestion. Due to the paucity of literature in managing pediatric patients with severe CCB toxicity, treatment strategies for pediatric patients are mostly limited to case reports and extrapolation from expert consensus recommendations for adults. All pediatric patients with a potentially toxic CCB ingestion should be evaluated in the emergency department. Activated charcoal may be considered for asymptomatic patients presenting within an hour of ingestion. Symptomatic patients should be placed under cardiac monitoring and treatments to stabilize the patient's hemodynamics should not be delayed. Traditional first-line IV therapies include small boluses of fluids, calcium, and vasopressors. High-dose insulin has been proposed to independently increase inotropy and improve CCB-induced hypoinsulinemia and insulin resistance that results from CCB inhibition of insulin release from pancreatic β-islet cells. High-dose insulin is recommended as first-line therapy for adults and shows promising efficacy and safety in several pediatric case reports. Intravenous lipid emulsion may be considered in patients who are refractory to first-line therapies, although the data for pediatric patients are extremely limited.

Searching for calcium antagonists for hypertension disease therapy from Moutan Cortex, using bioactivity integrated UHPLC-QTOF-MS

INTRODUCTION

Calcium channel blockers (CCBs) are currently the most commonly used drugs for the treatment of hypertension. Moutan Cortex (MC), a traditional Chinese herb, has been found to have an anti-hypertensive effect. However, its potential mechanisms in the regulation of intracellular calcium concentration ([Ca²⁺ ]_i ) remain poorly understood.

OBJECTIVE

The main objective of this work was to identify the potential calcium antagonists from MC and study their molecular mechanisms.

METHODS

Ultra-high performance liquid chromatography-quadrupole-time-of-fight-mass spectrometry (UHPLC-QTOF-MS) analysis combined with a dual-luciferase reporter assay was utilised to systematically screen the calcium antagonistic active ingredients in the methanol extract of MC. Additionally, the molecular mechanism of these compounds was further studied using live-cell imaging analysis with the calcium ion (Ca²⁺ ) probe dye fluo-4/AM to monitor changes in [Ca²⁺ ]_i .

RESULTS

Three monoterpenoids (paeoniflorin, benzoylpaeoniflorin and mudanpioside C), one phenolic acid (paeonol) and one gallotannin (1,2,3,4,6-O-pentagalloylglucose) were screened out as potential calcium antagonists in MC. Among them, the calcium antagonistic activity of benzoylpaeoniflorin, mudanpioside C and 1,2,3,4,6-O-pentagalloylglucose is first reported. Additionally, paeoniflorin, benzoylpaeoniflorin, mudanpioside C and paeonol can effectively block voltage-operated Ca²⁺ channels (VOCCs) to exert calcium antagonism, while 1,2,3,4,6-O-pentagalloylglucose plays a role in blocking inositol 1,4,5-trisphosphate receptors (IP3Rs).

CONCLUSION

This work indicated that the anti-hypertensive efficacy of MC acted through multiple components selectively antagonising multiple cell signalling pathways to regulate [Ca²⁺ ]_i . Furthermore, they could be considered as a reference standard for controlling the quality of Chinese medicinal materials.

An Update on Calcium Channel Blocker Toxicity in Dogs and Cats

The widespread use and availability of calcium channel blockers in human and veterinary medicine pose a risk for inadvertent pet exposure to these medications. Clinical signs of toxicosis can be delayed by many hours after exposure, with lethargy, hypotension, and cardiac rhythm changes as the predominant signs. Prompt decontamination and aggressive treatment using a variety of modalities may be necessary to treat patients exposed to calcium channel blockers. The prognosis of an exposed patient depends on the dose of the ingested calcium channel blockers, promptness of decontamination and other treatment measures, severity of clinical signs, and response to treatment.

Comprehensive review of cardiovascular toxicity of drugs and related agents

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

Searching for synergistic calcium antagonists and novel therapeutic regimens for coronary heart disease therapy from a Traditional Chinese Medicine, Suxiao Jiuxin Pill

Coronary heart disease is a vital cause of morbidity and mortality worldwide, and calcium channel blockers (CCBs) are important drugs that can be used to treat cardiovascular diseases. Suxiao Jiuxin Pill (SX), a traditional Chinese medicine, is widely used as an emergency drug for coronary heart disease therapy. However, understanding its potential mechanism in intracellular calcium concentration ([Ca²⁺]_i) modulation remains a challenge. To identify the active pharmacological ingredients (APIs) and reveal a novel combination therapy for ameliorating cardiovascular diseases, the ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) combined with a dual-luciferase reporter [Ca²⁺]_i assay system was applied. Ligustrazine, ferulic acid, senkyunolide I, senkyunolide A and ligustilide were identified as potential calcium antagonists in SX, and the combination of ligustrazine and senkyunolide A showed synergetic calcium antagonistic activity. Additionally, the synergetic mechanism was further investigated by live-imaging analysis with the Ca²⁺ indicator fluo-4/AM by monitoring fluorescence changes. Our results indicated that ligustrazine can block voltage-operated Ca²⁺ channels (VDCCs) effectively and senkyunolide A can exert an inhibition effect mostly on ryanodine receptors (RYRs) and partly on VDCCs. Finally, an arterial ring assay showed that the combination of ligustrazine and senkyunolide A exerted a better vasodilatation function than using any components alone. In this study, we first revealed that a pair of natural APIs in combination acting on VDCCs and RYRs was more effective on vasodilatation by regulating [Ca²⁺]_i.

Scientific research related to calcium channel blockers poisoning: Bibliometric analysis in Scopus, 1968-2012

PURPOSE

Calcium channel blockers (CCBs) were the most common agents associated with a significant morbidity and mortality rate. The main objective of this study was to examine the publication pattern related to CCBs poisoning at the global level using bibliometric analysis of articles published in SciVerse Scopus online database.

METHODS

Data were searched for documents that contained specific words regarding CCB poisoning as keywords in the title. No time period limitations were specified in the search regarding the starting year. The ending date of the search was 31 December 2012.

RESULTS

The criteria were met by 713 publications from 53 countries. The largest number of articles associated with CCBs was from the United States (30%), followed by the United Kingdom (7.4%), Japan (6%), and Germany (5.6%). No data related to CCBs were published from 159 (75%) of 212 countries registered in World Bank online database. There was no correlation between the number of published articles in the country and its population size (r = 0.03, p > 0.926). United Kingdom and Australia were the leading countries in terms of number of CCBs publications per million inhabitants (0.83 and 0.82 articles per million inhabitants, respectively), followed by the United States (0.68). Countries with a large population, such as India, tended to rank relatively low (0.01 articles per million inhabitants). The total number of citations at the time of data analysis (23 October 2014) was 6462, with an average of 9.1 citations per document. The highest median (interquartile range) number of citations was 8 (8-18) for the United States, followed by 6 (1-21) for Australia, 5 (1-15) for the United Kingdom, and 5 (1-24) for Canada. The h-index of the retrieved documents was 37.

CONCLUSIONS

Scientific production on CCBs poisoning is increasing; nonetheless, the international collaboration is still rare. The amount of CCBs-based research activity was low or not available in most countries. More regional epidemiological studies are required to bridge the gap in CCBs-based research and to promote better evaluation of CCBs poisoning worldwide.

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.

Pharmacotherapy of pediatric advanced life support and toxicological emergencies

Guidelines for pediatric advanced life support have been available for nearly a quarter of a century. Recommendations for the pharmacological management of pediatric cardiac arrest have changed over these years. Several important differences have been observed between adult advanced cardiac life support and pediatric advanced life support that must be recognized when children require resuscitation, such as the cause of the arrest, age-specific monitoring parameters, weight-based medication dosing, and obstacles in obtaining venous access. To make matters more complicated, differences also exist across neonatal and pediatric age spectrums. In addition, some toxicological emergencies commonly occurring in children require pharmacological management with agents that have a unique mechanism of action for cardiac support.

Combination of nifedipine and subtherapeutic dose of cyclosporin additively suppresses mononuclear cells activation of patients with rheumatoid arthritis and normal individuals via Ca(2+) -calcineurin-nuclear factor of activated T cells pathway

Abnormal Ca(2+) -mediated signalling contributes to the pathogenesis of rheumatoid arthritis (RA). However, the potential implication of calcium channel blocker in RA remained unknown. We hypothesized that nifedipine, an L-type calcium channel blocker, combined with a calcineurin inhibitor, could suppress T cell activation via targeting different level of the Ca(2+) signalling pathway. The percentage of activated T cells and the apoptotic rate of mononuclear cells (MNCs) was measured by flow cytometry. The MNC viability, cytokine production, cytosolic Ca(2+) level and activity of the nuclear factor of activated T cells (NFAT) were measured by enzyme-linked immunosorbent assay (ELISA). The NFAT-regulated gene expression, including interleukin (IL)-2, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF), was measured by real-time polymerase chain reaction (PCR). We found that the percentage of activated T cells in anti-CD3 + anti-CD28-activated MNC was higher in RA patients. High doses of nifedipine (50 µM) increased MNCs apoptosis, inhibited T cell activation and decreased T helper type 2 (Th1) (IFN-γ)/Th2 (IL-10) cytokine production in both groups. The Ca(2+) influx was lower in anti-CD3 + anti-CD28-activated MNC from RA patients than healthy volunteers and suppressed by nifedipine. When combined with a subtherapeutic dose (50 ng/ml) of cyclosporin, 1 µM nifedipine suppressed the percentage of activated T cells in both groups. Moreover, this combination suppressed more IFN-γ secretion and NFAT-regulated gene (GM-CSF and IFN-γ) expression in RA-MNCs than normal MNCs via decreasing the activity of NFATc1. In conclusion, we found that L-type Ca(2+) channel blockers and subtherapeutic doses of cyclosporin act additively to suppress the Ca(2+) -calcineurin-NFAT signalling pathway, leading to inhibition of T cell activity. We propose that this combination may become a potential treatment of RA.

Intralipid fat emulsion decreases respiratory failure in a rat model of parathion exposure

BACKGROUND

Therapies exist for acute organophosphate (OP) exposure but mortality rates remain high (10% to 20%). Currently, treatment focuses on reversing the resultant cholinergic excess effects through the use of atropine. Intralipid fat emulsion (IFE) has been used to treat lipophilic drug ingestions and theoretically would be beneficial for some OP agents.

OBJECTIVES

The hypothesis was that IFE would decrease the acute respiratory depressant effects following lethal OP exposure using a lipophilic OP agent (parathion).

METHODS

The authors used a previously validated animal model of OP poisoning with detailed physiologic respiratory recordings. The model consisted of Wistar rats anesthetized but spontaneously breathing 100% oxygen. Airflow, respiratory rate, tidal volume, mean arterial pressure, and pulse rate were digitally recorded for 120 minutes following OP exposure or until respiratory failure. Three study groups included parathion alone (n = 6), parathion and IFE 5 minutes after poisoning (n = 6), and parathion and IFE 20 minutes after poisoning (n = 6). In all groups, parathion was given as a single oral dose of 54 mg/kg (four times the rat oral 50% population lethal dose [LD(50) ]). Three boluses of IFE (15 mg/kg/min) were given over 3 minutes, 20 minutes apart, starting either 5 or 20 minutes after poisoning. Timing of IFE was based on parathion kinetics. In one study group IFE was initiated 5 minutes after poisoning to coincide with initial absorption of parathion. In another study group IFE was given at 20 minutes to coincide with peak intravenous (IV) parathion concentration. Primary outcome was percentage of animals with apnea. Secondary outcome was time to apnea.

RESULTS

Animals exposed to parathion alone demonstrated a steady decline in respiratory rate and tidal volume postexposure, with apnea occurring a mean of 51.6 minutes after poisoning (95% confidence interval [CI] = 35.8 to 53.2 minutes). Animals treated with IFE 5 minutes postexposure demonstrated no difference in mean time to apnea (44.5 minutes vs. 51.6 minutes, p = 0.29) or number of animals with respiratory arrest (100% vs. 100%, p = 1.00). Animals treated with IFE 20 minutes postexposure demonstrated a significantly prolonged mean time to apnea (95.3 minutes vs. 51.6 minutes, p = 0.002), but there was no difference in number of animals with respiratory arrest (100% vs. 66.7%, p = 0.45).

CONCLUSIONS

All animals exposed to 4 × LD(50) of oral parathion demonstrate apnea and respiratory arrest. IFE given immediately after oral parathion does not prolong time to apnea. IFE given 20 minutes after oral exposure to parathion decreases the acute effects of the OP and prolongs the time to apnea.