A Case of Severe, Refractory Hypotension After Amlodipine Overdose

Treatment Modalities in Calcium Channel Blocker Overdose: A Systematic Review

Calcium channel blocker poisoning is one of the most common poisonings encountered which presents with life-threatening complications. However, there is no unified approach for treating these patients in the existing literature. This study aimed to assess the effects of different treatment modalities used in calcium channel blocker poisoning, as reported by previous studies. The primary outcomes studied were mortality and hemodynamic parameters after treatment. The secondary outcomes were the length of hospital stay, length of intensive care unit stay, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations. A thorough literature search was performed through Ovid, PubMed, Cochrane Library, and Google Scholar from January 2014 to December 31, 2022, to identify all studies analyzing the effects of the treatment of calcium channel blocker poisoning on the desired outcomes. Two reviewers reviewed 607 published articles from January 2014 to December 2022 to identify studies analyzing the effects of the treatment of calcium channel blocker poisoning on desired outcomes. In this review, 18 case reports, one case series, and one cohort study were included. Most patients were treated with an injection of calcium gluconate or calcium chloride. The use of calcium along with dopamine and norepinephrine was found to have lower mortality rates. A few patients were also treated with injection atropine for bradycardia. High-dose insulin therapy was used in 14 patients, of whom two did not survive. In the cohort study, 66 calcium channel blocker toxicity patients were included. These patients were treated with high-dose insulin therapy. A total of 11 patients with calcium channel blocker toxicity succumbed. Although it was found to be associated with improved hemodynamic parameters and lower mortality, side effects such as hypokalemia and hypoglycemia were noted. Intravenous lipid emulsion therapy (administered to eight patients), extracorporeal life support (used in three patients with refractory shock or cardiac arrest), injection glucagon, methylene blue, albumin infusion, and terlipressin were associated with a lower mortality rate as well as improvement in hemodynamic parameters. None of the case reports provided any information on end-organ damage on long-term follow-up.

Amlodipine Overdose in a Transgender Woman: A Case Study

Calcium channel blockers are a major cause of cardiovascular toxicity. The clinical spectrum of these patients is very variable and there is no consensus on the dose required for toxicity. We present a case of a 43-year-old transgender woman who presented with hypotension and tachycardia owing to drug overdose that was later confirmed to be amlodipine. Given the catastrophic cascade of events involved with such toxicities, it is important to highlight amlodipine as one of the causes of drug overdose that can be overlooked.

Amlodipine Overdose: Is High Dose Insulin Ready for Prime Time

Overdose of amlodipine, a dihydropyridine calcium channel blocker (CCB), is distinguished from other CCBs due to longer plasma half-life of 30 to 58 h. As current management strategies of CCB overdose are diverse and institution dependent, this retrospective observational study aimed to compare treatment and outcomes data extracted from published case reports of amlodipine overdose with a cohort of patients diagnosed with amlodipine overdose at an urban tertiary medical center. Particular attention was paid to the use of high dose insulin euglycemic therapy (HIET) in treatment of amlodipine overdose. Data was extracted from actual adult patients hospitalized for amlodipine overdose at an urban tertiary medical center up to 2018, and from case reports of amlodipine overdose published between 1997 and 2020. We found a tendency towards earlier and more frequent initiation of HIET over time in management of amlodipine overdose, facilitating hospital discharge. Given the lack of randomized controlled trials comparing vasopressors, HIET, or other therapies, optimal treatment for amlodipine overdose has yet to be definitively established. Based on currently available evidence, a reasonable approach to management of the hemodynamically unstable patient presenting with amlodipine overdose includes vasopressors and inotropes with earlier initiation of HIET.

Extracorporeal treatment for calcium channel blocker poisoning: systematic review and recommendations from the EXTRIP workgroup

BACKGROUND

Calcium channel blockers (CCBs) are commonly used to treat conditions such as arterial hypertension and supraventricular dysrhythmias. Poisoning from these drugs can lead to severe morbidity and mortality. We aimed to determine the utility of extracorporeal treatments (ECTRs) in the management of CCB poisoning.

METHODS

We conducted systematic reviews of the literature, screened studies, extracted data, summarized findings, and formulated recommendations following published EXTRIP methods.

RESULTS

A total of 83 publications (6 in vitro and 1 animal experiments, 55 case reports or case series, 19 pharmacokinetic studies, 1 cohort study and 1 systematic review) met inclusion criteria regarding the effect of ECTR. Toxicokinetic or pharmacokinetic data were available on 210 patients (including 32 for amlodipine, 20 for diltiazem, and 52 for verapamil). Regardless of the ECTR used, amlodipine, bepridil, diltiazem, felodipine, isradipine, mibefradil, nifedipine, nisoldipine, and verapamil were considered not dialyzable, with variable levels of evidence, while no dialyzability grading was possible for nicardipine and nitrendipine. Data were available for clinical analysis on 78 CCB poisoned patients (including 32 patients for amlodipine, 16 for diltiazem, and 23 for verapamil). Standard care (including high dose insulin euglycemic therapy) was not systematically administered. Clinical data did not suggest an improvement in outcomes with ECTR. Consequently, the EXTRIP workgroup recommends against using ECTR in addition to standard care for patients severely poisoned with either amlodipine, diltiazem or verapamil (strong recommendations, very low quality of the evidence (1D)). There were insufficient clinical data to draft recommendation for other CCBs, although the workgroup acknowledged the low dialyzability from, and lack of biological plausibility for, ECTR.

CONCLUSIONS

Both dialyzability and clinical data do not support a clinical benefit from ECTRs for CCB poisoning. The EXTRIP workgroup recommends against using extracorporeal methods to enhance the elimination of amlodipine, diltiazem, and verapamil in patients with severe poisoning.

Lipid emulsion attenuates extrinsic apoptosis induced by amlodipine toxicity in rat cardiomyoblasts

Amlodipine-induced toxicity has detrimental effects on cardiac cells. The aim of this study was to examine the effect of lipid emulsion on decreased H9c2 rat cardiomyoblast viability induced by amlodipine toxicity. The effects of amlodipine, lipid emulsion, LY 294002, and glibenclamide, either alone or in combination, on cell viability and count, apoptosis, and expression of cleaved caspase-3 and -8, and Bax were examined. LY 294002 and glibenclamide partially reversed lipid emulsion-mediated attenuation of decreased cell viability and count induced by amlodipine. Amlodipine increased caspase-3 and -8 expression, but it did not alter Bax expression. LY 294002 and glibenclamide reversed lipid emulsion-mediated inhibition of cleaved caspase-3 and -8 expression induced by amlodipine. Lipid emulsion inhibited early and late apoptosis induced by amlodipine. LY 294002 and glibenclamide inhibited lipid emulsion-mediated inhibition of late apoptosis induced by amlodipine, but they did not significantly alter lipid emulsion-mediated inhibition of early apoptosis induced by amlodipine. Lipid emulsion decreased amlodipine-induced TUNEL-positive cells. These results suggest that lipid emulsion inhibits late apoptosis induced by amlodipine at toxic dose via the activation of phosphoinositide-3 kinase and ATP-sensitive potassium channels in the extrinsic apoptotic pathway.

Drug Dosing in Patients Undergoing Therapeutic Plasma Exchange

Therapeutic plasma exchange (TPE) is an extracorporeal process in which a large volume of whole blood is taken from the patient's vein. Plasma is then separated from the other cellular components of the blood and discarded while the remaining blood components may then be returned to the patient. Replacement fluids such as albumin or fresh-frozen plasma may or may not be used. TPE has been used clinically for the removal of pathologic targets in the plasma in a variety of conditions, such as pathogenic antibodies in autoimmune disorders. TPE is becoming more common in the neurointensive care space as autoimmunity has been shown to play an etiological role in many acute neurological disorders. It is important to note that not only does TPE removes pathologic elements from the plasma, but may also remove drugs, which may be an intended or unintended consequence. The objective of the current review is to provide an up-to-date summary of the available evidence pertaining to drug removal via TPE and provide relevant clinical suggestions where applicable. This review also aims to provide an easy-to-follow clinical tool in order to determine the possibility of a drug removal via TPE given the procedure-specific and pharmacokinetic drug properties.

Elimination of Intracellular Calcium Overload by BAPTA-AM-Loaded Liposomes: A Promising Therapeutic Agent for Acute Liver Failure

In the past few decades, intracellular calcium overload has been shown to induce cell death through multiple signaling pathways. In this study, we used BAPTA-AM, a well-known membrane-permeable Ca²⁺ chelator, to prevent cell injury by allaying the intracellular calcium overload. We explored the clinical potentials of BAPTA-AM-loaded liposome (BAL) in the treatment of the acute liver failure (ALF) mouse model, which is characterized by severe hepatic necrosis and apoptosis. We discovered that BAL can significantly inhibit D-GalN-induced LO2 cell damage as it increased cell viability by 60% and downregulated the LPS-stimulated inflammatory response in RAW 264.7 macrophages by reversing the morphological change and modulating TNF-α and NF-κB expressions. Through systemic administration, BAL can rapidly accumulate in damaged liver tissue and exhibit excellent treatment effects on the D-GalN/LPS-induced ALF mouse model, including elevation of the survival rate (from 10 to 80%), recovery of normal liver indexes and liver health indicators, improvement of liver blood microcirculation (increased the blood flow volume by 80% and flow rate by 60%), and blood coagulation. The underlying hepatoprotective effect of BAL is presumably based on the antinecrosis and antiapoptosis abilities attributed to its inhibition on oxidative stress, restriction on TNF-α receptor, and mitochondria-mediated apoptotic pathway by effectively clearing the overloaded intercellular calcium. BAL holds great potential as a new therapeutic strategy for ALF treatment, and its prominent cell rescue ability provides ample opportunities for the treatment of many other diseases that are characterized by rapid and massive cell damage.

Development and Feasibility of a Porcine Model of Amlodipine Toxicity

INTRODUCTION

Toxicity related to calcium-channel blockers remains a significant cause of morbidity and mortality. Amlodipine-induced shock is unique in that its mechanism of action is thought to occur in part via the release of nitric oxide (NO) in the peripheral vasculature. Specific therapeutic interventions, including methylene blue (an NO scavenger), have been suggested, but efficacy studies are severely limited. To facilitate a larger porcine study into the effect of various interventions on amlodipine toxicity, we undertook this model development and feasibility study.

METHODS

Intravenous amlodipine was prepared by dissolving commercially obtained amlodipine tablets in dimethylsulfoxide. The concentration of the drug was verified using ultraviolet spectroscopy. We administered this solution to three animals in order to determine a toxic dose, capable of facilitating a two-arm study of amlodipine toxicity.

RESULTS

The first pig died rapidly after the bolus infusion. The second pig developed mild toxicity, but the dissolution of the plastic tubing by the solvent and subsequent leakage limited the interpretability of the result. The third animal developed expected toxicity with an infusion rate between 2.0  and 5.5 mg/kg/h.

CONCLUSION

This study demonstrates a potentially repeatable model of amlodipine-induced toxic shock using intravenous administration of amlodipine and several methodological considerations for researchers undertaking similar work.

Literature review of the evidence regarding intravenous lipid administration in drug-induced cardiotoxicity

Introduction: Intravenous lipid emulsion (ILE) administration is capable of reversing the acute cardiac and neurological toxicity caused by local anesthetic agents. In recent years, ILE has also been explored as a potential antidote for cardiotoxicity caused by non-anesthetic agents too. Areas covered: The potential mechanisms, safety, and efficacy of this approach are considered. Data were sought from published reports listed in PubMed and EMBASE, and abstracts of meetings of the North American Congress of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. There were reports involving 298 patients where ILE has been administered for severe drug toxicity. Clinical improvement was observed in 57 of 59 patients with local anesthetic toxicity (96.6%); there were 239 patients where toxicity was due to non-anesthetic agents, and ILE apparently improved clinical outcome in 215 (72.1%). Expert opinion: Response rates were similar between ILE treated toxicity caused by lipid soluble and non-lipid soluble drugs. Potential adverse effects of ILE include interference with laboratory assays, acute pancreatitis, and adult respiratory distress syndrome, although the rate of occurrence is difficult to ascertain.

Comparative effectiveness of methylene blue versus intravenous lipid emulsion in a rodent model of amlodipine toxicity

Context: Calcium channel blocker (CCB) poisonings are the leading cause of death from cardiovascular medication-related overdoses. Current treatments (calcium salts, vasopressors, inotropes) are often insufficient. Intravenous lipid emulsion (ILE) and methylene blue (MB) show promise in treating CCB overdoses unresponsive to conventional therapy. Objective: To compare the effectiveness of MB versus ILE in a rodent model of amlodipine (AML) poisoning with survival as the primary outcome and hemodynamic parameters as secondary outcomes. Materials and methods: Sixty-four adult male albino rats were anesthetized and cannulated for non-invasive hemodynamic measurement. Rats received amlodipine intraperitoneally (42 mg/kg). We then divided the rats into four groups: AML only without antidote, AML followed by ILE (24.8 mL/kg over 10 min), AML followed by normal saline (an equivalent volume of ILE), and AML followed by IV MB (2 mg/kg over 5 min). They received study treatments at 5, 30, and 60 minutes from the start of the protocol and with observation for 2 hours. Results: Survival time in ILE group was greater than in the control and NS groups. Differences between ILE and MB and between MB and NS were not significant. Hemodynamic parameters significantly increased in ILE group compared to the MB group at the 30, 60 and 120 min assessments but not after induction of AML poisoning and at 5 min assessment. Conclusions: Survival was greatest in rats treated with ILE. Both MB and NS had little effect on survival when compared to control animals. Both ILE and MB improved hemodynamics.

Use of veno-venous extracorporeal membrane oxygenation to treat severe combined calcium channel blocker and angiotensin converting enzyme inhibitor overdose

INTRODUCTION

Calcium channel blockers (CCBs) are a commonly prescribed medication that, at toxic levels, are capable of causing severe refractory hypotension, hypoxic respiratory failure and cardiotoxicity. There is little evidence currently guiding the approach to managing CCB overdose, particularly when combined with other antihypertensive agents.

CASE REPORT

We describe the use of veno-venous extracorporeal membrane oxygenation (VV ECMO) in a previously healthy man following combined overdose with amlodipine and lisinopril in a suicide attempt. ECMO was used to provide oxygenation support, allowing for the amlodipine and lisinopril to be metabolized and cleared while also reducing ventilator-induced lung injury (VILI) and avoiding the complications associated with venous-arterial (VA) ECMO, such as differential hypoxemia.

CONCLUSION

Limited case reports suggesting the use of ECMO in CCB overdose have employed VA ECMO due to CCB-induced cardiotoxicity. We believe that, if cardiac function has been preserved, VV ECMO should be considered a viable treatment strategy for CCB and ACE-I overdose resulting in refractory hypoxemic respiratory failure.

A Fatal Case of Amlodipine Toxicity Following Iatrogenic Hypercalcemia

Using calcium salts in management of amlodipine overdose is challenging. A 25-year-old male with known history of adult polycystic kidney disease presented with hypotension, tachycardia, and intact neurological status after ingestion of 450 mg of amlodipine. Immediately, normal saline infusion and norepinephrine were initiated. Two grams of calcium gluconate was injected, followed by intravenous infusion of 1.16 mg/kg/h. The patient was put on insulin-glucose protocol to maintain euglycemia and hyperinsulinemia. Electrocardiography demonstrated junctional rhythm. Serum creatinine was 2.5 mg/dL with metabolic acidosis. By the end of 24 h post-admission, his consciousness, blood pressure, and urine output were normal. Almost 32 h post-admission, he became disoriented and his oxygen saturation decreased and therefore was mechanically ventilated. Second chest X-ray showed pulmonary edema. Serum calcium level increased to 26.1 mg/dL. Calcium was discontinued, and furosemide infusion and calcitonin were intravenously administrated. Urine output increased and hemodialysis improved pulmonary edema and serum calcium level with no change in consciousness. Three days after admission, the patient became anuric and developed multi-organ failure and died 5 days post-admission. To avoid the consequences of excessive infusion of calcium in renal failure patients, the minimum calcium dose with close monitoring is recommended.