Amiodarone

The use of antiarrhythmic drugs for atrial fibrillation in Finland 2007-2018

BACKGROUND

Patients with atrial fibrillation (AF) are often treated with antiarrhythmic drugs (AADs) to maintain sinus rhythm and with heart rate-lowering drugs to achieve the optimal rate control. In this study, we investigated trends in the use of AADs and rate control drugs in Finnish patients with AF.

METHODS AND RESULTS

The Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) study is a nationwide study including all patients with AF in Finland from 2007 to 2018. The number of AAD purchases and the proportions of all prevalent AF patients in a certain year of interest were calculated. In total, 391030 AF patients were identified between 2007 and 2018, and 39,816 (10.2%) of them had purchased either class I or III AADs. The proportion of patients using classes I and III AADs decreased from 8.6% to 6.3%. Flecainide and amiodarone were the most often used AADs. The use of flecainide and amiodarone decreased from 4.9% to 3.9% and 1.9% to 1.5%, respectively. The proportion of patients on beta-blockers remained stable at 75%. Dronedarone became available in 2011 when it also was the most used (0.8% of patients), but the use decreased thereafter. The use of sotalol and digoxin decreased from 1.5% to 0.6% and 24.6% to 11.0% over the study period.

CONCLUSION

The number of AAD purchases increased alongside with the increasing prevalence of AF, whereas the proportion of AF patients on classes I and III AADs and digoxin decreased between 2007 and 2018. Flecainide remained the most used AAD followed by amiodarone.

High content imaging of relative ATP levels for mitochondrial toxicity prediction in human induced pluripotent stem cell derived cardiomyocytes

Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are increasingly being evaluated in assays aimed at better understanding potential cardiotoxic liability of newly developed therapeutic compounds. Disruption of mitochondria has been implicated in the mechanism of drug-induced cardiotoxicity of some compounds. Therefore, we have developed a high content imaging assay for the investigation of mitochondrial toxicity in hiPSC-CMs using ATP-Red, a fluorescent dye capable of detecting subcellular localization of relative ATP levels in living cells. We demonstrated time-dependent decreases in ATP-Red signal over 6 h treatment with known mitochondrial toxicants antimycin (0.03, 0.1 µM) or oligomycin (3, 10 µM). Concentration-dependent decreases in ATP-Red signal with antimycin (0.001-0.3 µM) and oligomycin (0.003-1 µM) were rescued by restoring glycolysis through glucose supplementation. Decreased ATP levels were also identified in a selection of clinically available drugs with reported association with mitochondrial toxicity but absent in compounds with no known association with mitochondrial dysfunction. ATP measurements using the ATP-Red imaging assay were consistent with orthogonal measurements of whole cell ATP levels in lysed hiPSC-CMs following compound treatment. Similar findings were also obtained with measurement of mitochondrial membrane potential, except amiodarone which had no change despite decreased ATP levels. The developed high throughput imaging assay, assessing subcellular ATP dynamics, could provide mechanistic insights for tested compounds.

Drug-induced Acute Lung Injury: A Comprehensive Radiologic Review

Drug-induced acute lung injury is a significant yet often underrecognized clinical challenge, associated with a wide range of therapeutic agents, including chemotherapy drugs, antibiotics, anti-inflammatory drugs, and immunotherapies. This comprehensive review examines the pathophysiology, clinical manifestations, and radiologic findings of drug-induced acute lung injury across different drug categories. Common imaging findings are highlighted to aid radiologists and clinicians in early recognition and diagnosis. The review emphasizes the importance of immediate cessation of the offending drug and supportive care, which may include corticosteroids. Understanding these patterns is crucial for prompt diagnosis and management, potentially improving patient outcomes.

Population pharmacokinetic analysis of the interaction of digoxin with N-desethylamiodarone in patients with atrial fibrillation and heart failure

AIMS

To evaluate the effects of amiodarone and/or N-desethylamiodarone concentrations on digoxin pharmacokinetics and determine the optimal dose of digoxin combined with amiodarone in Japanese patients with atrial fibrillation and heart failure.

METHODS

A population pharmacokinetic analysis of 3288 points from 368 patients receiving oral digoxin, including 48 (13%) who were coadministered amiodarone, was performed. A 1-compartment model with first-order absorption with amiodarone or N-desethylamiodarone as time-varying covariates for apparent digoxin clearance was constructed using stepwise forward inclusion and backward elimination approaches. The percentage of patients with digoxin values in the toxic range (≥0.9 ng/mL) was evaluated with Monte Carlo simulation.

RESULTS

The median serum digoxin concentration was 0.75 ng/mL; the median plasma concentrations of amiodarone and N-desethylamiodarone were 610 and 644 ng/mL, respectively. The final model for oral clearance of digoxin was explained by creatinine clearance (CLcr) and the N-desethylamiodarone concentration. Digoxin clearance increased by 21% when CLcr was doubled and decreased by 3% when the N-desethylamiodarone concentration increased by 100 ng/mL. In the simulation, the proportion of patients with values in the toxic range was high at 0.125 mg daily among patients taking amiodarone. A daily dose of 0.0625 mg is recommended for patients with a CLcr >30 mL/min. For patients with a CLcr ≤30 mL/min and an N-desethylamiodarone concentration >600 ng/mL, a daily dose of 0.03125 mg is recommended because of reduced digoxin clearance.

CONCLUSIONS

This study revealed that renal impairment and high plasma N-desethylamiodarone concentrations reduce digoxin clearance in patients with atrial fibrillation and heart failure.

A disproportionality analysis of interstitial lung disease associated with drug therapy in spontaneous adverse event reports

BACKGROUND

Interstitial lung disease (ILD) is a group of disorders characterized by inflammation and fibrosis of lung tissue that make it hard to carry oxygen. Our study aimed to comprehensively evaluate the risk of drug-induced ILD using data from the FDA Adverse Event Reporting System (FAERS) database.

RESEARCH DESIGN AND METHODS

We queried the ILD reports from 2004 to 2023. The reporting odds ratio (ROR) and Bayesian Confidence Propagation Neural Network (BCPNN) were calculated to detect disproportionality signals for drugs associated with ILD.

RESULTS

A total of 39,332 ILD-related reports were identified. The most frequently reported drugs were Methotrexate (N = 1245), followed by Pembrolizumab (N = 1026), Amiodarone (N = 975), Rituximab (N = 915), and Doxorubicin (N = 911). Disproportionality analysis revealed significant signals for the top 50 drugs, including Trastuzumab deruxtecan (ROR 56.25, 95% CI 51.27-61.72; IC025 5.49), Ramucirumab (ROR 27.80, 95% CI 241.6-31.99; IC025 4.50), Amiodarone (ROR 24.35, 95% CI 22.82-25.99; IC025 4.40), Gefitinib (ROR 23.02, 95% CI 20.66-25.66; IC025 4.29), and Doxorubicin (ROR 13.99, 95% CI 13.09-14.95; IC025 3.64).

CONCLUSIONS

Drug-induced ILD represents a significant challenge in clinical practice. Our findings underscore the importance of maintaining a high index of suspicion for drug-induced ILD, particularly when prescribing medications identified as having significant associations with ILD.

Efficacy and safety of adenosine for supraventricular tachycardia: A meta-analysis utilizing BioMedGPT-LM-7B

BACKGROUND

Patients with supraventricular tachycardia (SVT) often experience multiple clinical symptoms that require emergency treatment. This study utilized BioMedGPT-LM-7B, an artificial intelligence (AI) model, to comprehensively evaluate the efficacy and adverse effects of adenosine/adenosine triphosphate (ATP) versus calcium channel blockers (CCBs) in SVT treatment.

METHODS

This study conducted a comprehensive search of multiple medical databases, as well as major trial registries up to December 2024. We performed dual screening and assessment using BioMedGPT-LM-7B and the traditional Cochrane bias risk tool. The primary outcomes were the rate of sinus rhythm restoration and major adverse events, while secondary outcomes included time to restoration, relapse to SVT post-reversion, and any minor adverse events. Outcome measurements were based on odds ratios (OR) and Mean Difference (MD), with the quality of primary outcomes assessed using the GRADE method.

RESULTS

This study included 10 RCTs with a total of 960 SVT patients admitted to the emergency department. Comparing BioMedGPT-LM-7B with the traditional Cochrane bias risk tool, we found no significant differences in random sequence generation and selective reporting. Moderate evidence showed no difference between adenosine/ATP and CCBs in restoring sinus rhythm (OR = 1.44, 95% CI [0.89,2.34]), but adenosine/ATP had a shorter time to reversion (MD = 423,24, 95% CI [293.54, 552.93]). However, the research findings show a lower level of evidence regarding differences in side effects among the drugs mentioned above. Three cases of hypotension were reported in the CCB group, whereas none were reported in the adenosine group.

CONCLUSION

Adenosine/ATP and CCBs have similar efficacy in treating SVT, but adenosine/ATP has a shorter conversion time and no reported cases of hypotension. Clinical studies indicate that adenosine has a higher success rate and faster conversion time in restoring sinus rhythm compared to ATP, with milder side effects. However, further prospective studies are needed to evaluate patient experience and potential adverse events, ensuring a more comprehensive understanding of treatment safety and efficacy. Additionally, this study showcases BioMedGPT-LM-7B's potential for medical data analysis and future meta-analyses.

Amiodarone Therapy: Updated Practical Insights

Amiodarone, a bi-iodinated benzofuran derivative, is among the most commonly used antiarrhythmic drugs due to its high level of effectiveness. Though initially categorized as a class III agent, amiodarone exhibits antiarrhythmic properties across all four classes of antiarrhythmic drugs. Amiodarone is highly effective in maintaining sinus rhythm in patients with paroxysmal atrial fibrillation while also playing a crucial role in preventing a range of ventricular arrhythmias. Amiodarone has a complex pharmacokinetic profile, characterized by a large volume of distribution and a long half-life, which can range from several weeks to months, resulting in prolonged effects even after discontinuation. Side effects may include thyroid dysfunction, pulmonary fibrosis, and hepatic injury, necessitating regular follow-ups. Additionally, amiodarone interacts with several drugs, including anticoagulants, which must be managed to prevent adverse effects. Therefore, a deep understanding of both oral and intravenous formulations, as well as proper dosage adjustments, is essential. The aim of this paper is to provide a comprehensive and updated review on amiodarone's indications, contraindications, recommended dosages, drug interactions, side effects, and monitoring protocols.

A Research Agenda to Improve Outcomes in Patients with Chronic Obstructive Pulmonary Disease and Cardiovascular Disease: An Official American Thoracic Society Research Statement

Background: Individuals with chronic obstructive pulmonary disease (COPD) are often at risk for or have comorbid cardiovascular disease and are likely to die of cardiovascular-related causes. Objectives: To prioritize a list of research topics related to the diagnosis and management of patients with COPD and comorbid cardiovascular diseases (heart failure, atherosclerotic vascular disease, and atrial fibrillation) by summarizing existing evidence and using consensus-based methods. Methods: A literature search was performed. References were reviewed by committee co-chairs. An international, multidisciplinary committee, including a patient advocate, met virtually to review evidence and identify research topics. A modified Delphi approach was used to prioritize topics in real time on the basis of their potential for advancing the field. Results: Gaps spanned the translational science spectrum from basic science to implementation: 1) disease mechanisms; 2) epidemiology; 3) subphenotyping; 4) diagnosis and management; 5) clinical trials; 6) care delivery; 7) medication access, adherence, and side effects; 8) risk factor mitigation; 9) cardiac and pulmonary rehabilitation; and 10) health equity. Seventeen experts participated, and quorum was achieved for all votes (>80%). Of 17 topics, ≥70% agreement was achieved for 12 topics after two rounds of voting. The range of summative Likert scores was -15 to 25. The highest priority was "Conduct pragmatic clinical trials with patient-centered outcomes that collect both pulmonary and cardiac data elements." Health equity was identified as an important topic that should be embedded within all research. Conclusions: We propose a prioritized research agenda with the purpose of stimulating high-impact research that will hopefully improve outcomes among people with COPD and cardiovascular disease.

Evaluation of Amiodarone Administration in Patients with New-Onset Atrial Fibrillation in Septic Shock

Background and Objective: New-onset atrial fibrillation (NOAF) is a common cardiac condition often observed in intensive care units. When amiodarone is used to treat this condition, either to maintain sinus rhythm after electrical cardioversion or to control heart rate, complications can arise when a systemic pathology is present. Systemic pathology can result in a decrease in cardiac output and blood pressure, making the management of NOAF and septic shock challenging. Limited international research exists on the coexistence of NOAF and septic shock, making it difficult to determine the optimal course of treatment. While amiodarone is not the primary choice of antiarrhythmic drug for patients in septic shock, it may be considered for those with underlying cardiac issues. This paper aims to investigate the safety of administering amiodarone to patients with septic shock and explore whether another antiarrhythmic drug may be more effective, especially considering the cardiac conditions that patients may have. Materials and Methods: To write this article, we searched electronic databases for studies where authors used amiodarone and other medications for heart rate control or sinus rhythm restoration. Results: The studies reviewed in this work have shown that for the patients with septic shock and NOAF along with a pre-existing cardiac condition like a dilated left atrium, the use of amiodarone may provide greater benefits compared to other antiarrhythmic drugs. For patients with NOAF and septic shock without underlying heart disease, the initial use of propafenone has been found to be advantageous. However, a challenge arises when deciding between rhythm or heart rate control using various drug classes. Unfortunately, there is limited literature available on this specific scenario. Conclusions: NOAF is a frequent and potentially life-threatening complication occurring in one out of seven patients with sepsis, and its incidence is rising among patients with septic shock.

Host-directed therapy with amiodarone in preclinical models restricts mycobacterial infection and enhances autophagy

Mycobacterium tuberculosis (Mtb) as well as nontuberculous mycobacteria are intracellular pathogens whose treatment is extensive and increasingly impaired due to the rise of mycobacterial drug resistance. The loss of antibiotic efficacy has raised interest in the identification of host-directed therapeutics (HDT) to develop novel treatment strategies for mycobacterial infections. In this study, we identified amiodarone as a potential HDT candidate that inhibited both intracellular Mtb and Mycobacterium avium in primary human macrophages without directly impairing bacterial growth, thereby confirming that amiodarone acts in a host-mediated manner. Moreover, amiodarone induced the formation of (auto)phagosomes and enhanced autophagic targeting of mycobacteria in macrophages. The induction of autophagy by amiodarone is likely due to enhanced transcriptional regulation, as the nuclear intensity of the transcription factor EB, the master regulator of autophagy and lysosomal biogenesis, was strongly increased. Furthermore, blocking lysosomal degradation with bafilomycin impaired the host-beneficial effect of amiodarone. Finally, amiodarone induced autophagy and reduced bacterial burden in a zebrafish embryo model of tuberculosis, thereby confirming the HDT activity of amiodarone in vivo. In conclusion, we have identified amiodarone as an autophagy-inducing antimycobacterial HDT that improves host control of mycobacterial infections.

IMPORTANCE

Due to the global rise in antibiotic resistance, there is a strong need for alternative treatment strategies against intracellular bacterial infections, including Mycobacterium tuberculosis (Mtb) and non-tuberculous mycobacteria. Stimulating host defense mechanisms by host-directed therapy (HDT) is a promising approach for treating mycobacterial infections. This study identified amiodarone, an antiarrhythmic agent, as a potential HDT candidate that inhibits the survival of Mtb and Mycobacterium avium in primary human macrophages. The antimycobacterial effect of amiodarone was confirmed in an in vivo tuberculosis model based on Mycobacterium marinum infection of zebrafish embryos. Furthermore, amiodarone induced autophagy and inhibition of the autophagic flux effectively impaired the host-protective effect of amiodarone, supporting that activation of the host (auto)phagolysosomal pathway is essential for the mechanism of action of amiodarone. In conclusion, we have identified amiodarone as an autophagy-inducing HDT that improves host control of a wide range of mycobacteria.

L-Carnitine Ameliorates Amiodarone-Mediated Alveolar Damage: Oxidative Stress Parameters, Inflammatory Markers, Histological and Ultrastructural Insights

The aim of this study was to assess L-carnitine's effects on adult male rats' lung damage brought on by amiodarone, which is a potent antiarrhythmic with limited clinical efficacy due to potentially life-threatening amiodarone-induced lung damage. Because of the resemblance among the structural abnormalities in rats' lungs that follows amiodarone medication and pulmonary toxicity in human beings, this animal model may be an appropriate example for this disease entity. Amiodarone produced pulmonary toxicity in twenty-four healthy male albino rats (150-180 g) over a period of 6 weeks. Four groups of six rats each were established: control, sham, amiodarone, and L-carnitine plus amiodarone. Histological, ultrastructural, oxidative stress, and inflammatory markers were determined during a 6-week exposure experiment. Amiodarone-induced lung damage in rats may be brought on due to oxidative stress producing significant pulmonary cytotoxicity, as evidenced by the disruption of the mitochondrial structure, severe fibrosis, and inflammatory response of the lung tissue. Lungs already exposed to such harmful effects may be partially protected by the antioxidant L-carnitine. Biochemical markers of lung damage brought on by amiodarone include lung tissue levels of the enzyme's catalase, superoxide dismutase, and reduced glutathione. The levels of lipid peroxides in lung tissue measured as malondialdehyde increased significantly upon exposure to amiodarone. In addition, the levels of tumor necrosis factor alpha were significantly elevated in response to amiodarone. The effect of L-carnitine on amiodarone-induced pulmonary toxicity was studied in rats. It is interesting to note that the intake of L-carnitine in rats treated with amiodarone partially restored the biochemical and histopathological alterations brought on by amiodarone to their original levels. Tumor necrosis factor alpha levels were significantly reduced upon L-carnitine exposure. These results suggest that L-carnitine can be used to treat amiodarone-induced pulmonary dysfunction.

Imaging of the Spectrum of Acute Lung Injury

Organizing pneumonia, acute fibrinous and organizing pneumonia, and diffuse alveolar damage, represent multi-compartment patterns of lung injury. The initial region of injury in all remains the same and is centered on the fused basement membrane (BM) between the capillary endothelium and type I pneumocyte. Injury leads to cellular death, BM denudation, increased cellular permeability, and BM structural damage, which leads to exudation, organization, and attempts at repair. When acute lung injury does lead to fibrosis, in some instances it can lead to histologic and/or radiologic usual interstitial pneumonia or nonspecific interstital pneumonia patterns suggesting that lung injury is the primary mechanism for the development of fibrosis.

Drugs Associated with Adverse Effects in Vulnerable Groups of Patients

In recent years, a series of recommendations have been issued regarding the administration of drugs because of awareness of the serious side effects associated with certain classes of drugs, especially in vulnerable patients. Taking into account the obligation of the continuous improvement of professionals in the medical fields and the fact that we are in the midst of a "malpractice accusations pandemic", through this work, we propose to carry out a "radiography" of the scientific literature regarding adverse effects that may occur as a result of the interaction of drugs with the physiopathological particularities of patients. The literature reports various cases regarding different classes of drugs administration associated with adverse effects in the elderly people, such as fluoroquinolones, which can cause torsade de pointes or tendinopathy, or diuretics, which can cause hypokalemia followed by torsade de pointes and cardiorespiratory arrest. Also, children are more prone to the development of adverse reactions due to their physiological particularities, while for pregnant women, some drugs can interfere with the normal development of the fetus, and for psychiatric patients, the use of neuroleptics can cause agranulocytosis. Considering the physiopathological particularities of each patient, the drug doses must be adjusted or even completely removed from the treatment scheme, thus requiring the mandatory active participation both of clinician pharmacists and specialists in the activity of medical-pharmaceutical analysis laboratories within the structure of hospitals.

Multidisciplinary Management of Patients With Chronic Obstructive Pulmonary Disease and Cardiovascular Disease

Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) frequently coexist, increasing the prevalence of both entities and impacting on symptoms and prognosis. CVD should be suspected in patients with COPD who have high/very high risk scores on validated scales, frequent exacerbations, precordial pain, disproportionate dyspnea, or palpitations. They should be referred to cardiology if they have palpitations of unknown cause or angina pain. COPD should be suspected in patients with CVD if they have recurrent bronchitis, cough and expectoration, or disproportionate dyspnea. They should be referred to a pulmonologist if they have rhonchi or wheezing, air trapping, emphysema, or signs of chronic bronchitis. Treatment of COPD in cardiovascular patients should include long-acting muscarinic receptor antagonists (LAMA) or long-acting beta-agonists (LABA) in low-risk or high-risk non-exacerbators, and LAMA/LABA/inhaled corticosteroids in exacerbators who are not controlled with bronchodilators. Cardioselective beta-blockers should be favored in patients with CVD, the long-term need for amiodarone should be assessed, and antiplatelet drugs should be maintained if indicated.

Life cell imaging of amiodarone sequestration into lamellar bodies of alveolar type II cells

Amiodarone is widely used to treat cardiac arrhythmias and is very effective in preventing these disorders. However, its use is limited by a wide range of adverse effects, mainly affecting the lungs, and ranging from mild shortness of breath to pulmonary fibrosis. Amiodarone has been shown to accumulate strongly in lung tissue, exceeding its plasma concentration by a hundredfold. However, the site of accumulation and the mechanisms of transport are not fully understood. In this study, we used live cell imaging of primary rat alveolar type II cells to show that amiodarone specifically accumulates in large amounts in lamellar bodies, the surfactant storage organelles. Fluorescence imaging and correlation, and colocalization studies combined with confocal Raman microscopy identified these organelles as a major target for sequestration. Accumulation was rapid, on the order of a few hours, while storage was much more persistent. Partial uptake was observed in chemically fixed, dead cells, or cells treated with bafilomycin A1. Not only was uptake pH dependent, but intraluminal pH, measured with lysosomotropic pH sensitive dyes, was also affected. From these observations and from the physicochemical properties of amiodarone, we propose that passive diffusion, ion-trapping and lipophilic interactions are the main mechanisms for intracellular bioaccumulation. Furthermore, we demonstrate that measurement of amiodarone autofluorescence is highly useful for tracking cellular uptake and sequestration.

Drug-induced interstitial lung disease: a narrative review of a clinical conundrum

INTRODUCTION

Drug-induced interstitial lung disease (DI-ILD) is increasing in incidence, due to the use of many new drugs across a broad range of cancers and chronic inflammatory diseases. The presentation and onset of DI-ILD are variable even for the same drug across different individuals. Clinical suspicion is essential for identifying these conditions, with timely drug cessation an important determinant of outcomes.

AREAS COVERED

This review provides a comprehensive and up-to-date summary of epidemiology, risk factors, pathogenesis, diagnosis, treatment, and prognosis of DI-ILD. Relevant research articles from PubMed and Medline searches up to September 2023 were screened and summarized. Specific drugs including immune checkpoint inhibitors, CAR-T cell therapy, methotrexate, and amiodarone are discussed in detail. The potential role of pharmacogenomic profiling for lung toxicity risk is considered.

EXPERT OPINION

DI-ILD is likely to be an increasingly important contributor to respiratory disability in the community. These conditions can negatively impact quality of life and patient longevity, due to associated respiratory compromise as well as cessation of evidence-based therapy for the underlying disease. This clinical conundrum is relevant to all areas of medicine, necessitating increased understanding and greater vigilance for drug-related lung toxicity.

Too Little, Too Late: A Case of a Swift Fatal Culmination of Amiodarone Induced Pulmonary Toxicity in an Adult Male

Amiodarone is a commonly prescribed antiarrhythmic drug. It can cause a myriad of complications associated with its long-term use, with amiodarone induced pulmonary toxicity being the worst. Amiodarone does this through its destructive properties and its' ability to accumulate if taken for extended periods of time or in high cumulative doses. Albeit uncommon, the management of amiodarone induced pulmonary toxicity can be straightforward if recognized early. Otherwise, it can lead to severe respiratory failure causing death. In this case report, we aim to highlight the importance of vigilance with clinicians prescribing amiodarone and to spark interests into research for alternative management options of amiodarone induced pulmonary toxicity. This will be done through the description of a case of a 64-year-old male presenting with cough and dyspnoea, who has been on a large dose of amiodarone daily for the past 11 months. He was diagnosed too little, too late, which unfortunately culminated in his rapid fatality. This case is unique for two reasons. The diagnosis of amiodarone induced pulmonary toxicity was through the clinical picture - without the use of invasive investigations. In addition, the futile cessation of amiodarone and use of high dose systemic corticosteroids as a management - which to our knowledge is uncommon in literature.

Capturing time-dependent activation of genes and stress-response pathways using transcriptomics in iPSC-derived renal proximal tubule cells

Transcriptomic analysis is a powerful method in the utilization of New Approach Methods (NAMs) for identifying mechanisms of toxicity and application to hazard characterization. With this regard, mapping toxicological events to time of exposure would be helpful to characterize early events. Here, we investigated time-dependent changes in gene expression levels in iPSC-derived renal proximal tubular-like cells (PTL) treated with five diverse compounds using TempO-Seq transcriptomics with the aims to evaluate the application of PTL for toxicity prediction and to report on temporal effects for the activation of cellular stress response pathways. PTL were treated with either 50 μM amiodarone, 10 μM sodium arsenate, 5 nM rotenone, or 300 nM tunicamycin over a temporal time course between 1 and 24 h. The TGFβ-type I receptor kinase inhibitor GW788388 (1 μM) was used as a negative control. Pathway analysis revealed the induction of key stress-response pathways, including Nrf2 oxidative stress response, unfolding protein response, and metal stress response. Early response genes per pathway were identified much earlier than 24 h and included HMOX1, ATF3, DDIT3, and several MT1 isotypes. GW788388 did not induce any genes within the stress response pathways above, but showed deregulation of genes involved in TGFβ inhibition, including downregulation of CYP24A1 and SERPINE1 and upregulation of WT1. This study highlights the application of iPSC-derived renal cells for prediction of cellular toxicity and sheds new light on the temporal and early effects of key genes that are involved in cellular stress response pathways.

Variable radiographic and histologic presentations of amiodarone-related interstitial lung disease and the importance of avoiding re-exposure

Amiodarone is a commonly used antiarrhythmic agent but exhibits potential pulmonary toxicity. In this case series, we describe the clinical, radiographic, and histologic manifestations of three patients who developed interstitial lung disease (ILD) following amiodarone treatment for variable lengths of time with different dosages. The presentations on computed tomographic images and in pulmonary pathology differed among the three patients. All three had immediate discontinuation of amiodarone and received treatment with systemic corticosteroids. One patient eventually died from ventilator-associated pneumonia after an initial improvement. The other two patients recovered well but later experienced ILD recurrence following brief re-exposure to amiodarone. Through this case series, we aim to demonstrate the variable features of amiodarone-related ILD, and highlight the importance of timely amiodarone cessation and avoiding re-exposure to prevent the progression and recurrence of ILD.

Amiodarone-Induced Lung Toxicity: A Case Initially Not Correctly Framed

Amiodarone-induced pulmonary toxicity (AIPT) is one of the most serious adverse effects of amiodarone and is one of the leading causes of death associated with its use. The onset of AIPT depends on dosage, patient's age, and pre-existing pulmonary pathologies; typically, the adverse effects stop progressing when a cumulative dose higher than 150 mg is reached. The risk of developing amiodarone-induced pulmonary fibrosis is directly related to the dosage and duration of administration. In this case report, the effect of a prolonged overdose of amiodarone taken at doses of 200 mg/day for two years is reported, with symptoms and instrumental evidence of respiratory pathology induced by amiodarone drug toxicity. Comorbidities, oxygen therapy, invasive procedures, and surgical interventions can trigger pulmonary symptoms. Despite significant advances in understanding AIPT, its etiology and pathogenesis remain poorly understood. The role of steroids in the treatment of AIPT is still under debate as most reports of improvement after amiodarone withdrawal differ little from those in which concomitant steroid therapy was used. In clinical practice, therapeutic doses of corticosteroids may be indicated for patients with AIPT; usually, a starting dose of prednisone from 40 to 60 mg daily, which is then gradually reduced, is prescribed. The pharmacodynamics of amiodarone determines a treatment period of four to 12 months. The patient with AIPT in this case report, who markedly improved after treatment with prednisone at a starting dose of 50 mg/day, which was then gradually tapered. At the end of the therapy, the computed tomography (CT) scan revealed the disappearance of most of the scattered ground-glass opacities and of the thickening indicating bi-apical pulmonary fibrosis. The case report is unique because: 1) Bronchoalveolar lavage (BAL)/transbronchial biopsy was not used for diagnosis. 2) The case was framed based on the patient's laboratory and clinical data. 3) The pathology is normally prevalent in men rather than women.

Diffuse alveolar hemorrhage and acute eosinophilic pneumonia: A rare form of amiodarone pulmonary toxicity diagnosed by bronchoalveolar lavage

A 56-year-old man presented with fever, cough, and bloody sputum. He had undergone mitral valve replacement with mechanical prosthesis 14 months prior for mitral valve disease. Subsequently, the patient was taking warfarin and amiodarone. Chest imaging revealed dense, infiltrative shadows, and blood tests showed prolonged prothrombin time and eosinophilia. Warfarin was withdrawn, and antibiotics were started, but bloody sputum and respiratory failure persisted. Considering that eosinophilia was observed after the administration of amiodarone, the drug was discontinued, and bronchoalveolar lavage was performed. Cytology showed foam cells, eosinophils, and hemosiderin-laden macrophages; amiodarone-induced diffuse alveolar hemorrhage (DAH) and acute eosinophilic pneumonia (AEP) were diagnosed, and the patient was treated with corticosteroids. This report describes the first documented case of amiodarone-induced DAH and AEP. When a patient taking amiodarone presents with antibiotic-refractory pneumonia with bloody sputum and eosinophilia, amiodarone-induced DAH and AEP should be considered.

Learning objective

We report the first case of amiodarone-induced diffuse alveolar hemorrhage (DAH) and acute eosinophilic pneumonia (AEP) diagnosed by foam cells, eosinophils, and hemosiderin-laden macrophages on bronchoalveolar lavage cytology. When a patient taking amiodarone presents with antibiotic-refractory pneumonia with bloody sputum and eosinophilia, amiodarone-induced DAH and AEP should be considered.

Amiodarone for the Treatment of Arrhythmias in COVID-19 Patients Does Not Increase the Risk of Pulmonary Fibrosis: A Retrospective Cohort Study

Amiodarone is a class III antiarrhythmic medication used to treat atrial and ventricular tachyarrhythmias. Pulmonary fibrosis from amiodarone use is a well-documented side effect. Pre-COVID-19 pandemic studies have shown that amiodarone-induced pulmonary fibrosis occurs in 1%-5% of patients and usually occurs between 12 to 60 months after initiation. The risk factors associated with amiodarone-induced pulmonary fibrosis include a high total cumulative dose (treatment longer than two months) and high maintenance dose (>400 mg/day). COVID-19 infection is also a known risk factor for developing pulmonary fibrosis and occurs in approximately 2%-6% of patients after a moderate illness. This study aims to assess the incidence of amiodarone in COVID-19 pulmonary fibrosis (ACPF). This is a retrospective cohort study with 420 patients with COVID-19 diagnoses between March 2020 and March 2022, comparing two populations, COVID-19 patients with exposure to amiodarone (N=210) and COVID-19 patients without amiodarone exposure (N=210). In our study, pulmonary fibrosis occurred in 12.9% of patients in the amiodarone exposure group compared to 10.5% of patients in the COVID-19 control group (p=0.543). In multivariate logistic analysis, which controlled for clinical covariates, amiodarone use in COVID-19 patients did not increase the odds of developing pulmonary fibrosis (odds ratio (OR): 1.02, 95% confidence interval (CI): 0.52-2.00). The clinical factors associated with the development of pulmonary fibrosis in both groups included a history of preexisting interstitial lung disease (ILD) (p=0.001), exposure to prior radiation therapy (p=0.021), and higher severity of COVID-19 illness (p<0.001). In conclusion, our study found no evidence that amiodarone use in COVID-19 patients increased the odds of developing pulmonary fibrosis at six-month follow-up. However, long-term amiodarone usage in the COVID-19 population should be based on the physician's discretion.

Nicorandil mitigates amiodarone-induced pulmonary toxicity and fibrosis in association with the inhibition of lung TGF-β1/PI3K/Akt1-p/mTOR axis in rats

The long-term side effect of the antiarrhythmic drug, amiodarone (AMIO), such as lung toxicity, remains a critical clinical issue. The previous knowledge denotes diverse antioxidant, anti-inflammatory, and antifibrotic properties of the anti-anginal drug, nicorandil (NI). Therefore, we aimed to investigate the possible protective effect of NI on pulmonary tissue remodelling following AMIO-induced lung toxicity. The included rats were assigned into four equal groups (n = 8): (1) control, (2) control group that received NI 10 mg kg^-1  day^-1 , (3) model group that received AMIO in a dose of 60 mg kg^-1  day^-1 , and (4) treated group (AMIO-NI) that were treated with AMIO plus NI as shown above. Drug administration continued for 10 weeks. AMIO resulted in deteriorated (p < 0.001) pulmonary functions accompanied by respiratory acidosis. AMIO showed an obvious histological injury score with intense collagen deposition, disturbed nitric oxide synthase enzymes (NOS/iNOS), and increased alpha smooth muscle actin expression. Furthermore, AMIO upregulated the transforming growth factor (TGF-β1)/phosphoinositide-3 kinase (PI3K)-Akt1-p/mammalian target of rapamycin (mTOR) axis, which determined the possible mechanism of AMIO on pulmonary remodelling. NI treatment significantly (p < 0.001) prevented the AMIO-induced lung toxicity, as well as inhibited the TGF-β1/PI3K/Akt1-p/mTOR axis in the lung tissue of rats. The results were confirmed by an in-vitro study. CONCLUSION: The current results revealed that NI was effective in preserving the lung structure and functions. Amelioration of the oxidative stress and modulation of TGF-β1/PI3K/Akt1-p/mTOR have been achieved. This study suggests NI administration as a preventive therapy from the serious pulmonary fibrosis side effect of AMIO.

Pulmonary Fibrosis Related to Amiodarone-Is It a Standard Pathophysiological Pattern? A Case-Based Literature Review

Amiodarone hydrochloride is an antiarrhythmic drug, with proven efficacy in prevention and treatment of numerous arrhythmias, atrial fibrillation especially, or ventricular arrhythmias, with a long half-life (55-60 days). The increased risk of developing amiodarone-induced pulmonary fibrosis is directly related to the dose and the duration of the intake. Amiodarone-induced pulmonary toxicity is conditioned by dose, patient's age, and pre-existent pulmonary pathologies. The pattern for drug-induced lung injury may vary in many forms, but the amiodarone can cause polymorphous injuries such as diffuse alveolar damage, chronical interstitial pneumonia, organizing pneumonia, pulmonary hemorrhage, lung nodules or pleural disease. The pathological mechanism of pulmonary injury induced by amiodarone consists of the accumulation of phospholipid complexes in histocytes and type II pneumocytes. Differential diagnosis of pulmonary fibrosis induced by amiodarone is made mainly with idiopathic pulmonary fibrosis, left ventricular failure or infectious disease. Before starting treatment with amiodarone, patients should be informed of potential adverse effects and any new respiratory symptoms should promptly be reported to their family physician or attending physician. The assessment carried out at the initiation of amiodarone treatment should include at least chest X-ray and respiratory function tests and extrapulmonary evaluation.

Use of Visual Electrophysiology to Monitor Retinal and Optic Nerve Toxicity of Medications

It is important for clinicians to consider exposure to toxic substances and nutritional deficiencies when diagnosing and managing cases of vision loss. In these cases, physiologic damage can alter the function of key components of the visual pathway before morphologic changes can be detected by traditional imaging methods. Electrophysiologic tests can aid in the early detection of such functional changes to visual pathway components, including the retina or optic nerve. This review provides an overview of various electrophysiologic techniques, including multifocal electroretinogram (mfERG), full-field ERG (ffERG), electrooculogram (EOG), pattern electroretinogram (PERG), and visual evoked potential (VEP) in monitoring the retinal and optic nerve toxicities of alcohol, amiodarone, cefuroxime, cisplatin, deferoxamine, digoxin, ethambutol, hydroxychloroquine, isotretinoin, ocular siderosis, pentosane, PDE5 inhibitors, phenothiazines (chlorpromazine and thioridazine), quinine, tamoxifen, topiramate, vigabatrin, and vitamin A deficiency.

Organizing pneumonia secondary to amiodarone treatment

Amiodarone is a widely prescribed antiarrhythmic drug with a relatively high incidence of adverse effects associated with its long-term oral use. Pulmonary toxicity may manifest as organizing pneumonia, which responds well to amiodarone discontinuation and corticosteroid treatment. We present a case of an organizing pneumonia secondary to amiodarone treatment, discuss the diagnostic approach and provide tips for an accurate diagnosis based on imaging findings. A brief literature review is performed.

Population Pharmacokinetic Model of Amiodarone and N-Desethylamiodarone Focusing on Glucocorticoid and Inflammation

Some population pharmacokinetic models for amiodarone (AMD) did not incorporate N-desethylamiodarone (DEA) concentration. Glucocorticoids activate CYP3A4 activity, metabolizing AMD. In contrast, CYP3A4 activity may decrease under inflammation conditions. However, direct evidence for the role of glucocorticoid or inflammation on the pharmacokinetics of AMD and DEA is lacking. The pilot study aimed to address this gap using a population pharmacokinetic analysis of AMD and DEA. A retrospective cohort observational study in adult patients who underwent AMD treatment with trough concentration measurement was conducted at Tokyo Women's Medical University, Medical Center East from June 2015 to March 2019. Both structural models of AMD and DEA applied 1-compartment models, which included significant covariates using a stepwise forward selection and backward elimination method. The eligible 81 patients (C-reactive protein level: 0.26 [interquartile range; 0.09-1.92] mg/dL) had a total of 408 trough concentrations for both AMD and DEA. The median trough concentrations were 0.49 [0.31-0.81] µg/mL for AMD and 0.43 [0.28-0.71] µg/mL for DEA during a median follow-up period of 446 [147-1059] d. Three patients received low-dose oral glucocorticoid. The final model identified that AMD clearance was 7.9 L/h, and the apparent DEA clearance was 10.3 L/h. Co-administered glucocorticoids lowered apparent DEA clearance by 35%. These results indicate that co-administered glucocorticoids may increase DEA concentrations in patients without severe inflammation.

Phenols in Pharmaceuticals: Analysis of a Recurring Motif

Phenols and phenolic ethers are significant scaffolds recurring both in nature and among approved small-molecule pharmaceuticals. This compendium presents the first comprehensive compilation and analysis of the structures of U.S. FDA-approved molecules containing phenol or phenolic ether fragments. This dataset comprises 371 structures, which are strongly represented by natural products. A total of 55 of the compounds described here are on the World Health Organization's list of essential medicines. Structural analysis reveals significant differences in the physicochemical properties imparted by phenols versus phenol ethers, each having benefits and drawbacks for drug developability. Despite trends over the past decade to increase the fraction of sp³ centers in drug leads, thereby "escaping flatland", phenols and phenolic ethers are represented in 62% of small-molecule drugs approved in 2020, suggesting that this aromatic moiety holds a special place in drugs and natural products.

PRMT5 in T Cells Drives Th17 Responses, Mixed Granulocytic Inflammation, and Severe Allergic Airway Inflammation

Severe asthma is characterized by steroid insensitivity and poor symptom control and is responsible for most asthma-related hospital costs. Therapeutic options remain limited, in part due to limited understanding of mechanisms driving severe asthma. Increased arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), is increased in human asthmatic lungs. In this study, we show that PRMT5 drives allergic airway inflammation in a mouse model reproducing multiple aspects of human severe asthma. We find that PRMT5 is required in CD4⁺ T cells for chronic steroid-insensitive severe lung inflammation, with selective T cell deletion of PRMT5 robustly suppressing eosinophilic and neutrophilic lung inflammation, pathology, airway remodeling, and hyperresponsiveness. Mechanistically, we observed high pulmonary sterol metabolic activity, retinoic acid-related orphan receptor γt (RORγt), and Th17 responses, with PRMT5-dependent increases in RORγt's agonist desmosterol. Our work demonstrates that T cell PRMT5 drives severe allergic lung inflammation and has potential implications for the pathogenesis and therapeutic targeting of severe asthma.

Acute amiodarone pulmonary toxicity in the form of organizing pneumonia triggered by orthotopic heart transplantation

We report a case of a 60-year-old man who underwent orthotopic heart transplantation after short-term receipt of low-dose oral amiodarone for the management of ventricular tachycardia. Prior to transplant surgery, he had a normal chest radiograph and was free of supplemental oxygen. His initial postoperative chest radiograph showed subtle infiltrates, and thereafter his chest imaging continued to worsen. Although he was eventually able to wean off mechanical ventilation via a tracheostomy, he remained dyspneic and oxygen-dependent with persistently abnormal chest imaging as his post-transplant corticosteroid regimen was being tapered. In light of progressively worsening diffuse lung disease, he underwent bronchoscopy with transbronchial biopsies. Histology revealed foamy macrophages in association with foci of organizing pneumonia, a picture consistent with amiodarone pulmonary toxicity. Given these findings, corticosteroid dosing was increased for the clinical diagnosis of acute amiodarone pulmonary toxicity with subsequent normalization of oxygen saturation and chest radiography. Our case is the first to identify orthotopic heart transplantation as a potential trigger for acute amiodarone pulmonary toxicity. It is also only the second documented example of organizing pneumonia as the histological substrate of amiodarone pulmonary toxicity, which is an association that has therapeutic implications.

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Amiodarone pulmonary toxicity can present acutely, often precipitated by cardiothoracic interventions.

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Organizing pneumonia has only rarely been shown to underlie acute amiodarone pulmonary toxicity.

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Orthotopic heart transplantation surgery was the putative trigger in the present case, making this the first such description.

New nanotechnological formulation based on amiodarone-loaded lipid core nanocapsules displays anticryptococcal effect

Cryptococcus neoformans is the etiological agent of cryptococcal meningoencephalitis. The recommended available treatment has low efficiency, with high toxicity and resistance as recurrent problems. In the search of new treatment protocols, the proposal of new pharmacological approaches is considered an innovative strategy, mainly nanotechnological systems considering fungal diseases. The antiarrhythmic drug amiodarone has demonstrated antifungal activity against a range of fungi, including C. neoformans. Here, considering the importance of calcium storage mediated by transporters on cryptococcal virulence, we evaluated the use of the calcium channel blocker amiodarone as an alternative therapy for cryptococcosis. C. neoformans displayed high sensitivity to amiodarone, which was also synergistic with fluconazole. Amiodarone treatment influenced some virulence factors, interrupting the calcium-calcineurin signaling pathway. Experiments with murine cryptococcosis models revealed that amiodarone treatment increased the fungal burden in the lungs, while its combination with fluconazole did not improve treatment compared to fluconazole alone. In addition, we have developed different innovative nanotechnological formulations, one of which combining two drugs with different mechanisms of action. Lipid-core nanocapsules (LNC) loaded with amiodarone (LNC_AMD), fluconazole (LNC_FLU) and both (LNC_AMD+FLU) were produced to achieve a better efficacy in vivo. In an intranasal model of treatment, all the LNC formulations had an antifungal effect. In an intraperitoneal treatment, LNC_AMD showed an enhanced anticryptococcal effect compared to the free drug, whereas LNC_FLU or LNC_AMD+FLU displayed no differences from the free drugs. In this way, nanotechnology using amiodarone formulations could be an effective therapy for cryptococcal infections.

Amiodarone-induced organizing pneumonia mimicking COVID-19: a case report

BACKGROUND

Differential diagnosis of interstitial lung diseases (ILDs) during the COVID-19 pandemic is difficult, due to similarities in clinical and radiological presentation between COVID-19 and other ILDs on the one hand, and frequent false-negative swab results on the other. We describe a rare form of interstitial and organizing pneumonia resembling COVID-19, emphasizing some key aspects to focus on to get the right diagnosis and treat the patient properly.

CASE PRESENTATION

A 76-year-old man presented with short breath and dry cough in the midst of the COVID-19 outbreak. He showed bilateral crackles and interstitial-alveolar opacities on X-ray, corresponding on computed tomography (CT) to extensive consolidations with air bronchograms, surrounded by ground glass opacities (GGO). Although his throat-and-nasopharyngeal swab tested negative, the picture was overall compatible with COVID-19. On the other hand, he showed subacute, rather than hyperacute, clinical onset; few and stable parenchymal consolidations, rather than patchy and rapidly evolving GGO; pleural and pericardial thickening, pleural effusion, and lymph node enlargement, usually absent in COVID-19; and peripheral eosinophilia, rather than lymphopenia, suggestive of hypersensitivity. In the past year, he had been taking amiodarone for a history of ventricular ectopic beats. CT scans, in fact, highlighted hyperattenuation areas suggestive of amiodarone pulmonary accumulation and toxicity. Bronchoalveolar lavage fluid (BALF) investigation confirmed the absence of coronavirus genome in the lower respiratory tract; conversely, high numbers of foamy macrophages, eosinophils, and cytotoxic T lymphocytes with low CD4/CD8 T-cell ratio were detected, confirming the hypothesis of amiodarone-induced cryptogenic organizing pneumonia. Timely discontinuation of amiodarone and initiation of steroid therapy led to resolution of respiratory symptoms, systemic inflammation, and radiographic opacities.

CONCLUSIONS

A comprehensive analysis of medical and pharmacological history, clinical onset, radiologic details, and peripheral and BALF cellularity, is required for a correct differential diagnosis and management of ILDs in the COVID-19 era.

Cicatricial organizing pneumonia associated with fibrosing interstitial pneumonia - A clinicopathological study

BACKGROUND

The recent recognition of the cicatricial organizing pneumonia (ciOP) indicates that the ciOP may resemble or simulate fibrotic interstitial pneumonia; however, there has been great uncertainty regarding the affected populations, pathogenesis, clinical relevance, and characteristics. In this study, we compared the characteristics of fibrotic interstitial pneumonia with and without ciOP.

METHOD

We enrolled 121 patients from the consultation archive whose pathological findings were fibrotic interstitial pneumonia and for whom follow-up clinical data were available. We reviewed these cases histopathologically and classified them according to whether or not they showed ciOP. We compared the clinicopathological features between the two groups.

RESULT

CiOP histopathologically characterized by deposition of dense collagenous fibers within the alveolar space without destruction of the lung structure was found in 48 patients (39.7%). None of the cases with ciOP experienced acute exacerbation during 12 months follow-up. The group with ciOP had more severe diffusion impairment but this, along with restrictive ventilatory impairment, improved significantly compared to the group without ciOP.

CONCLUSION

CiOP is a histopathological finding commonly found in fibrotic interstitial pneumonia. It does not relate to acute exacerbation or decrease in pulmonary function.

Amiodarone lung: under recognised but not forgotten

Amiodarone is a common medication used widely in clinical practice. It is a triiodinated antiarrhythmic associated with a variety of adverse effects both pulmonary and extrapulmonary, the most serious being amiodarone-induced pulmonary toxicity (AIPT) or amiodarone lung. This can present with a variety of clinical syndromes ranging from subacute symptoms to an indolent and a progressive course thus mimicking an alternative diagnosis. We report a case of amiodarone lung in a female who presented with an acute fulminant progressive pneumonitis despite being on very low dose (100 mg once daily) that proved fatal. Diagnosis was made on postmortem examination due to a diagnostic conundrum. Despite the steady decrease of AIPT with reduced dose, it is vital for the treating clinicians to monitor regularly for adverse effects and review the need for long-term use to prevent complications.

From the Heart to the Lung: A Case of Drug Toxicity

Patient: Female, 71-year-old

Final Diagnosis: Drug toxicity

Symptoms: Dry cough • dyspnea

Medication: —

Clinical Procedure: Drug withdrawal

Specialty: Pulmonology

Current Drug Treatment Strategies for Atrial Fibrillation and TASK-1 Inhibition as an Emerging Novel Therapy Option

Atrial fibrillation (AF) is the most common sustained arrhythmia with a prevalence of up to 4% and an upwards trend due to demographic changes. It is associated with an increase in mortality and stroke incidences. While stroke risk can be significantly reduced through anticoagulant therapy, adequate treatment of other AF related symptoms remains an unmet medical need in many cases. Two main treatment strategies are available: rate control that modulates ventricular heart rate and prevents tachymyopathy as well as rhythm control that aims to restore and sustain sinus rhythm. Rate control can be achieved through drugs or ablation of the atrioventricular node, rendering the patient pacemaker-dependent. For rhythm control electrical cardioversion and pharmacological cardioversion can be used. While electrical cardioversion requires fasting and sedation of the patient, antiarrhythmic drugs have other limitations. Most antiarrhythmic drugs carry a risk for pro-arrhythmic effects and are contraindicated in patients with structural heart diseases. Furthermore, catheter ablation of pulmonary veins can be performed with its risk of intraprocedural complications and varying success. In recent years TASK-1 has been introduced as a new target for AF therapy. Upregulation of TASK-1 in AF patients contributes to prolongation of the action potential duration. In a porcine model of AF, TASK-1 inhibition by gene therapy or pharmacological compounds induced cardioversion to sinus rhythm. The DOxapram Conversion TO Sinus rhythm (DOCTOS)-Trial will reveal whether doxapram, a potent TASK-1 inhibitor, can be used for acute cardioversion of persistent and paroxysmal AF in patients, potentially leading to a new treatment option for AF.

Amiodarone is associated with increased short-term mortality in elderly atrial fibrillation patients with preserved ejection fraction

PURPOSE

Amiodarone is commonly used in atrial fibrillation (AF). Long-term use of amiodarone is associated with significant toxicities especially in elderly patients. However, in the short term after hospitalization of AF, it remains uncertain whether the use of amiodarone will increase mortality. We aim to investigate whether Amiodarone affects short-term mortality in elderly patients after hospitalization for atrial fibrillation.

METHODS

We conducted a single-center retrospective cohort study including patients (Age > = 60 years old) who were hospitalized between 07/01/2004 and 06/30/2019 with primary diagnosis of AF and left ventricular ejection fraction (LVEF) > = 50%. Patients who were prescribed amiodarone during hospitalization but not before hospitalization are classified into Amiodarone group (341 patients). Patients who were not prescribed amiodarone are classified into non-amiodarone group (2171 patients). Propensity score matching was performed with 1:1 nearest-neighbor matching of Amiodarone group and Non-amiodarone group based on baseline variables. Univariate and Multivariate logistic regression were used to calculate the odds ratio of amiodarone use on in-hospital mortality, and multivariate cox regression was adopted to calculate the hazard ratio of amiodarone use on 100-day mortality.

RESULTS

Patients' baseline demographic and clinical characteristics were well matched in both groups. Both univariate and multivariate logistic regression showed amiodarone group had higher in-hospital mortality (OR 10.27, p = 0.0268; 16.50, p = 0.0171) than non-amiodarone group and multivariate Cox regression suggested increased 100-day all-cause mortality (HR 2.34, p = 0.022).

CONCLUSION

Amiodarone use in elderly patients with preserved ejection fraction is associated with increased in-hospital and 100-day all-cause mortality after hospitalization for AF.

Anti-arrhythmic investigations in large animal models of atrial fibrillation

Atrial fibrillation (AF) constitutes an increasing health problem in the aging population. Animal models reflecting human phenotypes are needed to understand the mechanisms of AF, as well as to test new pharmacological interventions. In recent years, a number of large animal models, primarily pigs, goats, dog and horses have been used in AF research. These animals can to a certain extent recapitulate the human pathophysiological characteristics and serve as valuable tools in investigating new pharmacological interventions for treating AF. This review focuses on anti-arrhythmic investigations in large animals. Initially, spontaneous AF in small and large mammals is discussed. This is followed by a short presentation of frequently used methods for inducing short- and long-term AF. The major focus of the review is on anti-arrhythmic compounds either frequently used in the human clinic (ranolazine, flecainide, vernakalant and amiodarone) or being promising new AF medicine candidates (I_K,Ach , I_SK,Ca and I_K2P blockers).

Sinus Rhythm Maintenance After Electrical Cardioversion for Atrial Fibrillation in High-Risk Patients — Comparative Efficacy of Antiarrhythmic Medications

Atrial fibrillation (AF) conversion to sinus rhythm by electrical cardioversion (ECV) is followed by the challenge of preventing arrhythmia recurrence, especially in high-risk patients. The properties of class IC, class III and also class II antiarrhythmic medications have been established, but not all effects have been studied. The aim of the study was to compare efficacy of class IC and class III antiarrhythmic medications, and additionally medication with a class II mechanism of action, or taken concomitantly with a beta-blocker, for post-cardioversion sinus rhythm maintenance in patients with high-risk AF. A total of 112 patients who underwent successful ECV in Latvian Centre of Cardiology were included. Data was acquired by a face-to-face interview and 1-, 3-, 6-month follow-up interviews. Comparing class IC (used by 34.8%) and class III (used by 65.2%) drugs, there was no statistically significant difference between six-month sinus rhythm maintenance rates (53.8% vs. 63.0%, p = 0.346) and arrhythmia-free survival (p = 0.313). Comparing amiodarone (used by 57.1%) and ethacizine, concurrently with a beta-blocker (used by 25.9%), no statistically significant difference was found between six-month sinus rhythm maintenance (64.1% vs. 58.6%, p = 0.616) and arrhythmia-free survival (p = 0.706). The results showed that specific antiarrhythmic drug choice was not associated with superior effectiveness, highlighting that, if not contraindicated, ethacizine, concomitantly with a beta-blocker, could be used as a similarly effective alternative for amiodarone, which has adverse health effects.

[Drug-induced interstitial lung diseases]

Pulmonary drug reactions are a relatively common factor causing interstitial pulmonary disease. Histological findings of pulmonary drug reactions can mimic other conditions such as various forms of idiopathic interstitial pneumonia such as nonspecific interstitial pneumonia, organizing pneumonia, diffuse alveolar damage, or usual interstitial pneumonia. The correct diagnosis is important since a causal therapy is possible by stopping the administration. A stringent correlation between dose/time of administration and the type of reaction exists for only a few drugs. An increased risk of drug side effects can arise from known reactions to that specific drug, the patient's history, the type of underlying disease, genetic polymorphisms, occupational factors, and interactions with other drugs. The identification of a pulmonary drug reaction is a difficult task that can often only be solved in an interdisciplinary manner, for which in rare cases a lung biopsy is necessary. Pathology then has to identify histomorphological reaction patterns to exclude other causes and correlate findings with clinical data. In most cases, however, the diagnosis of a drug reaction will be by exclusion.

A nontrivial differential diagnosis in COVID-19 pandemic: a case report and literary review of amiodarone-induced interstitial pneumonia

Amiodarone is a drug commonly used to treat and prevent cardiac arrhythmias, but it is often associated with several adverse effects, the most serious of which is pulmonary toxicity. A 79-year-old man presented with respiratory failure due to interstitial pneumonia during the COVID-19 pandemic. The viral etiology was nevertheless excluded by repeated nasopharyngeal swabs and serological tests and the final diagnosis was amiodarone-induced organizing pneumonia. The clinical and computed tomography findings improved after amiodarone interruption and steroid therapy. Even during a pandemic, differential diagnosis should always be considered and pulmonary toxicity has to be taken into account in any patient taking amiodarone and who has new respiratory symptoms.

Amiodarone: A Comprehensive Guide for Clinicians

Amiodarone is an effective antiarrhythmic medication frequently used in practice for both ventricular and atrial arrhythmias. Though classified as a class III antiarrhythmic, it affects all phases of the cardiac action potential. However, the drug has several side effects, including thyroid abnormalities, pulmonary fibrosis, and transaminitis, for which routine monitoring is recommended. It also interacts with several medications, such as warfarin, simvastatin, and atorvastatin, and many HIV antiretroviral medications. Given the common use of this medication in medical practice, it is vital that clinicians understand the indications, contraindications, dosing, side effects, and interactions of this medication. A thorough understanding of these topics is essential for clinicians to ensure safe and effective use of amiodarone.

Acute Amiodarone Pulmonary Toxicity

Amiodarone is an effective antiarrhythmic that frequently is used during the perioperative period. Amiodarone possesses a significant adverse reaction profile. Amiodarone-induced pulmonary toxicity (AIPT) is among the most serious adverse effects and is a leading cause of death associated with its use. Despite significant advances in the understanding of AIPT, its etiology and pathogenesis remain incompletely understood. The diagnosis of AIPT is one of exclusion. The clinical manifestations of AIPT are categorized broadly as acute, subacute, and chronic. Acute AIPT is a rarer and more aggressive form of the disease, most often encountered in cardiothoracic surgery. Acute respiratory distress syndrome (ARDS) is the predominating pattern of amiodarone's acute pulmonary toxicity. The incidence, risk factors, pathogenesis, and diagnosis of acute AIPT are speculative. Early cardiothoracic literature investigating AIPT often attributed amiodarone to the development of postoperative ARDS. Subsequent studies have found no association between amiodarone and acute AIPT and ARDS development. As a drug that is frequently prescribed to a patient population deemed most at risk for this fatal disease, the conflicting evidence on acute AIPT needs further investigation and clarification.

Role of bone marrow-derived mesenchymal stem cells in alleviating pulmonary epithelium damage and extracellular matrix remodeling in a rat model of lung fibrosis induced by amiodarone

The therapeutic role of mesenchymal stem cells (MSCs) in cases of amiodarone (AD) induced pulmonary fibrosis (PF) has not been well studied. Also, the period required by MSCs to attain full therapeutic effectiveness has not yet been assessed. We investigated the potential curative effect of bone marrow-derived MSCs (BM-MSCs) and conditioned media (CM) from BM-MSCs on AD induced PF by focusing on pulmonary epithelium injury and repair, and extracellular matrix (ECM) remodeling. We used 64 Wistar rats divided into eight groups: negative control group; PF group; three PF groups treated with BM-MSCs for 1, 2 or 4 months; and three PF groups treated with CM for 1, 2 and 4 months. Serum levels of Clara cell secretory protein (CC16) and keratinocyte growth factor (KGF) were measured. Gene expression of type I collagen (COL1A1) and connective tissue growth factor (CTGF) was evaluated in pulmonary tissue. Treatment of PF challenged rats with BM-MSCs or CM caused reduced CC16 levels, increased KGF levels, reduced expression of COL1A1 and CTGF, histological improvement following lung injury, and decreased collagen accumulation. Treatment with BM-MSCs exhibited greater amelioration of PF than CM. BM-MSCs or CM treatment for 2 and 4 months exhibited better resolution of fibrosis than treatment for 1 month. BM-MSCs are promising for treating PF due to their attenuation of ECM deposition in addition to alleviating pulmonary epithelium damage and initiating its repair.