Amiodarone-Induced Life-Threatening Refractory Hypotension

Amiodarone-Induced Anaphylaxis

Background: Amiodarone-induced anaphylaxis is seldom reported. The mechanism of this anaphylaxis is unknown. Methods: A literature search was carried out with keywords "Amiodarone" and "Anaphylaxis" and "polysorbate 80" or "hypotension." A search using "amiodarone" in the FDA Adverse Event Reporting System (FAERS) from 1969 to 2024 was also conducted. Results: There are a total of 10 cases of amiodarone-induced anaphylaxis in the literature. Six patients were male. Ages ranged from 15 to 86 years old. Nine cases were triggered by intravenous injection (IV) and one by oral administration. Eight patients did not have previous exposure to amiodarone. The trigger times for IV amiodarone were immediate to 90 minutes. All nine cases of IV amiodarone resulted in hypotension (90%), with an immeasurable blood pressure (70%). Presentations included bronchospasm or a skin rash (60%), angioedema (40%), and unconsciousness (20%). Only one patient had a history of allergy to penicillin and sulfonamide. An amiodarone skin test was positive on one patient. Increased blood tryptase (4 cases), positive basophil activation test to amiodarone (2 cases), increased eosinophil count (1 case), and increased serum IgE (1 case) were reported. Amiodarone was terminated in 80% of the patients. Epinephrine, norepinephrine, antihistamine-1, or steroids were used to rescue patients. Four patients were intubated. All patients fully recovered. In the FAERS database, 89 cases of amiodarone-associated anaphylaxis were reported, resulting in 14 deaths. Conclusions: Solvent polysorbate 80, amiodarone, and iodide may contribute to amiodarone-induced anaphylaxis. Prompt treatment is the key to saving patients.

Ventricular fibrillation likely resulting from electrocautery and amiodarone: a rare clinical case report

Monopolar electrocautery is usually a safe and effective technique used in laparoscopic cholecystectomy and bile duct surgery, but it may lead to adverse consequences, even ventricular fibrillation (VF). Amiodarone is an effective antiarrhythmic drug commonly used in practice to treat ventricular and atrial arrhythmias, but it may induce tachyarrhythmia or even VF. We report a case of VF occurring twice during cholecystectomy. The first VF was caused by low-frequency leakage current of the monopolar electrocautery. The second VF was due to amiodarone causing further prolongation of the corrected QT interval. By performing cardiopulmonary resuscitation and defibrillation, the patient recovered and was eventually discharged in good condition. In cholecystectomy surgery, especially when separating adhesive tissue from liver, caution should be exercised when using a monopolar electrotome, which is recommended to stop bleeding in the bipolar mode. After cardiopulmonary resuscitation, caution should be exercised when using amiodarone to prevent arrhythmia, even if prolongation of the corrected QT interval does not reach the diagnostic indicators of 470 ms for men and 480 ms for women. In addition, defibrillators should be in standby mode during the perioperative period.

Managing drug-drug interactions with mavacamten: A focus on combined use of antiarrhythmic drugs and anticoagulants

Mavacamten is a selective, allosteric, and reversible cardiac myosin inhibitor, representing the first disease-specific treatment for obstructive hypertrophic cardiomyopathy (HCM) that targets the core pathophysiological mechanism of this condition. Clinical evidence supports its efficacy in improving symptoms, cardiac function, and remodeling, thereby supplementing established treatment regimens. However, mavacamten is extensively metabolized by hepatic cytochromes, and its half-life is contingent upon CYP2C19 phenotype. Consequently, coadministered medications that inhibit or induce these enzymes may significantly alter mavacamten pharmacokinetics, potentially leading to reversible systolic dysfunction or diminished therapeutic efficacy. This paper provides a comprehensive analysis of mavacamten pharmacokinetics and its potential interactions with antithrombotic and antiarrhythmic agents, which are the cornerstones of atrial fibrillation management in HCM population. Our aim is to offer clinicians practical guidance on safely administering mavacamten in conjunction with these medications, discuss the role of pharmacogenomics, and outline rigorous patient safety monitoring strategies to ensure effective and individualized treatment.

Microencapsulation for Pharmaceutical Applications: A Review

In order to improve bioavailability, stability, control release, and target delivery of active pharmaceutical ingredients (APIs), as well as to mask their bitter taste, to increase their efficacy, and to minimize their side effects, a variety of microencapsulation (including nanoencapsulation, particle size <100 nm) technologies have been widely used in the pharmaceutical industry. Commonly used microencapsulation technologies are emulsion, coacervation, extrusion, spray drying, freeze-drying, molecular inclusion, microbubbles and microsponge, fluidized bed coating, supercritical fluid encapsulation, electro spinning/spray, and polymerization. In this review, APIs are categorized by their molecular complexity: small APIs (compounds with low molecular weight, like Aspirin, Ibuprofen, and Cannabidiol), medium APIs (compounds with medium molecular weight like insulin, peptides, and nucleic acids), and living microorganisms (such as probiotics, bacteria, and bacteriophages). This article provides an overview of these microencapsulation technologies including their processes, matrix, and their recent applications in microencapsulation of APIs. Furthermore, the advantages and disadvantages of these common microencapsulation technologies in terms of improving the efficacy of APIs for pharmaceutical treatments are comprehensively analyzed. The objective is to summarize the most recent progresses on microencapsulation of APIs for enhancing their bioavailability, control release, target delivery, masking their bitter taste and stability, and thus increasing their efficacy and minimizing their side effects. At the end, future perspectives on microencapsulation for pharmaceutical applications are highlighted.

A Rare Case of Intravenous Amiodarone Toxicity

Amiodarone is a highly effective treatment for life-threatening supraventricular and ventricular arrhythmias, namely in the setting of acutely decompensated heart failure. However, it could be associated with several serious adverse effects both in long-term oral therapy and in short-term use of intravenous (IV) preparation, including shock and liver injury. We report an unusual case of life-threatening refractory hypotension associated with acute hepatitis and renal failure a few hours after initiation of IV amiodarone. A 70-year-old man was admitted to the emergency department (ED) with dyspnea, chest discomfort, and a non-productive cough. Physical examination and complementary diagnostic tests helped diagnose acutely decompensated heart failure due to atrial fibrillation (AF) with a rapid ventricular response, and IV amiodarone was started. A few hours after initiating this drug, the patient developed hypotension with the need for inotropic therapy, acute elevation of amino transaminases, and renal failure. Renal function and liver transaminases returned to baseline after discontinuing amiodarone. A Roussel Uclaf Causality Assessment Method (RUCAM) score of 5 identifies our patient`s acute hepatitis as a possible adverse drug reaction. Refractory hypotension and liver injury with acute hepatitis after a short-term IV amiodarone therapy are extremely rare with few previously reported cases. Therefore, it is very important to perform continuous hemodynamic monitoring of the patient and liver function monitorization during short-term IV administration of this drug because these complications can be potentially fatal. A high index of suspicion is the key to functional organic recovery.

Ibutilide Reduces Ventricular Defibrillation Threshold and Organizes Ventricular Fibrillation Activation in Canine Heart Failure Model

PURPOSE

To compare the effects of class III antiarrhythmic agents (amiodarone vs. ibutilide) on ventricular fibrillation (VF) and hemodynamic status in a canine heart failure (HF) model.

METHODS

A total of 12 beagles were used to establish the HF model by rapid pacing for 4 consecutive weeks. These canines were randomly divided into two groups based on the administration of ibutilide and amiodarone. A 12 × 12 unipolar electrode plaque was used for ventricular epicardial mapping, and a 6-electrode plunge needle was inserted for ventricular transmural mapping. The restitution curve was estimated from activation recovery intervals (ARIs) by pacing from the plaque electrodes before and after drug administration. The defibrillation threshold (DFT) and VF activation patterns, including the activation rate, cycle length (VF-CL) and the transmural dispersion of the activation rate, were evaluated and the hemodynamic parameters were mearsured and compared before and after drug administration.

RESULTS

Compared to HF baseline, ibutilide administration has markedly decreased the DFT by 28% (18 ± 2 J vs. 13 ± 2.7 J, P < 0.01) without affecting the canine's hemodynamics (mean arterial pressure 91 ± 15 mmHg vs. 92 ± 17 mmHg, P > 0.05). Furthermore, VF activation pattern became more organized, and spontaneous termination was observed only after ibutilide administration. Conversely, amiodarone has significantly compromised the hemodynamic status (mean arterial pressure 92 ± 6.1 mmHg vs. 52 ± 11.6 mmHg, P < 0.05), but did not alter the DFT (17 ± 2.3 J vs. 16 ± 2.0 J, P > 0.05). Compared to pre-medication, both ibutilide and amiodarone have significantly prolonged the VERP (178 ± 9.6 ms vs. 208 ± 8.9 ms, P < 0.05; 185 ± 10.5 ms vs. 202 ± 7.5 ms, P < 0.05, respectively) and reduced the dispersion of refractoriness, the maximal slope of restitution curve, and the epicardial dispersion during pacing. Additionally, both drugs have significantly increased the VF-CL and reduced the transmural dispersion of the VF activation rate.

CONCLUSIONS

Ibutilide had potential antifibrillatory properties, which was shown by decreasing the DFT and organizing the VF activation in HF, and with no apparent impact on the hemodynamic status. In contrast, intravenous amiodarone administration demonstrated prominent negative effects on the hemodynamic status possibly by affecting the myocardial contractility before and after defibrillation but did not alter the DFT.

Cardiovascular Collapse with Intravenous Amiodarone in Children: A Multi-Center Retrospective Cohort Study

OBJECTIVE

To determine the incidence of cardiovascular collapse in children receiving intravenous (IV) amiodarone and to identify the population at risk.

DESIGN

A multicenter study of patients ≤ 18 years of age who received intravenous amiodarone between January 2005 and December 2015. A retrospective analysis was performed to identify patients who developed cardiovascular collapse (bradycardia and/or hypotension).

RESULTS

Of 456 patients who received amiodarone, cardiovascular collapse occurred in 47 patients (10%). Patient risk factors for collapse in a univariate analysis were as follows: age < 3 months (p = 0.04), depressed cardiac function (p < 0.001), blood pressure below 3rd percentile (p < 0.001), high lactate at baseline (p < 0.001). Administration risk factors included bolus administration (p = 0.04), and bolus administration over ≤ 20 min (p = 0.04). In multivariate analysis, age, baseline blood pressure less than 3rd percentile, and rapid bolus delivery were independent risk factors for cardiovascular collapse in the study group. The mortality rate was significantly higher in the collapse group (28% versus 8%).

CONCLUSION

We found an association between IV amiodarone administration and the risk of developing cardiovascular collapse in a significant subset of children. Extreme caution and careful hemodynamic monitoring is recommended when using IV amiodarone in this population, especially in young infants, hemodynamically compromised patients, and in patients receiving rapid amiodarone bolus administration.

Amiodarone Compared with Lidocaine for Out-Of-Hospital Cardiac Arrest with Refractory Ventricular Fibrillation on Hospital Arrival: a Nationwide Database Study

PURPOSE

The latest resuscitation guidelines recommend the use of amiodarone in adult patients with out-of-hospital cardiac arrest (OHCA) and refractory ventricular fibrillation (VF) to improve the rates of return of spontaneous circulation. However, there is limited evidence to suggest that amiodarone is superior to lidocaine with respect to survival at discharge. The purpose of the present study was to evaluate the hypothesis that amiodarone is superior to lidocaine with regard to the rate of survival to hospital discharge for OHCA patients with VF/pulseless VT (pVT) on hospital arrival.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we identified 3951 patients from 795 hospitals who experienced cardiogenic OHCA and had refractory ventricular fibrillation on hospital arrival between July 2007 and March 2013. The patients were categorized into amiodarone (n = 1743) and lidocaine (n = 2208) groups, from which 801 propensity score-matched pairs were generated.

RESULTS

There was no significant difference in the rate of survival to hospital discharge between the amiodarone and lidocaine groups (15.2 % vs. 17.1 %; difference, -1.9 %; 95 % CI, -5.5 to 1.7) in propensity score-matched analyses. Cox regression analyses did not indicate significant in-hospital mortality differences between the amiodarone and lidocaine groups for the propensity score-matched groups (hazard ratio, 1.05; 95 % CI, 0.94 to 1.17).

CONCLUSIONS

The present nationwide study suggested that there was no significant difference in the rate of survival to hospital discharge between cardiogenic OHCA patients with persistent ventricular fibrillation on hospital arrival treated with amiodarone or lidocaine.

Underexpression of CACNA1C Caused by Overexpression of microRNA-29a Underlies the Pathogenesis of Atrial Fibrillation

Background

The objective of this study was to investigate the molecular mechanism of atrial fibrillation (AF), as well as the negative regulatory relationship between miR-29a-3p and CACNA1C.

Material/Methods

We searched the online miRNA database (www.mirdb.org) and identified the miR-29a-3p binding sequence within the 3′-UTR of the target gene, and then conducted luciferase assay to verify it. The cells were transfected with miR-29a-3p and I_Ca,L was determined in those cells.

Results

We validated CACNA1C to be the direct target gene of miR-29a-3p. We also established the negative regulatory relationship between miR-29a-3p and CACNA1C via studying the relative luciferase activity. We also conducted real-time PCR and Western blot analysis to study the mRNA and protein expression level of CACNA1C among different groups of cells treated with scramble control, 30nM miR-29a-3p mimics, and 60nM miR-29a-3p mimics, indicating a negative regulatory relationship between miR-29a-3p and CACNA1C. We next analyzed whether miR-29a-3p transfection in cardiomyocytes produced the effects on the I_Ca,L induced by electrical remodeling, and found a tonic inhibition of I_Ba by endogenous miR-29a-3p in atrial myocytes.

Conclusions

We validated the negative regulation between miR-29a-3p and CACNA1C, and found that miR-29a-3p might a potential therapeutic target in the treatment of AF.