Amiodarone

Response to and recovery from treatment in human liver-mimetic clinostat spheroids: a model for assessing repeated-dose drug toxicity

Medicines are usually prescribed for repeated use over shorter or longer times. Unfortunately, repeated-dose animal toxicity studies do not correlate well with observations in man. As emphasized by the '3Rs' and the desire to phase-out animal research, in vitro models are needed. One potential approach uses clinostat-cultured 3D HepG2-C3A liver-mimetic spheroids. They take 18 days to recover in vivo physiological functionality and reach a metabolic equilibrium, which is thereafter stable for a year. Acute and chronic repeated-dose studies of six drugs (amiodarone, diclofenac, metformin, phenformin, paracetamol and valproic acid) suggest that spheroids are more predictive of human in vivo toxicity than either 2D-cultured HepG2 cells or primary human hepatocytes. Repeated non-lethal treatment results in a clear response and return to equilibrium. Mitochondrial toxic compounds can be identified using a galactose-based medium. Some drugs induced a protective (or stress) response that intensifies after the second treatment. This 3D spheroid model is inexpensive, highly reproducible and well-suited for the determination of repeated-dose toxicity of compounds (naturally or chemically synthesized).

Alveolar lipids in pulmonary disease. A review

Lung lipid metabolism participates both in infant and adult pulmonary disease. The lung is composed by multiple cell types with specialized functions and coordinately acting to meet specific physiologic requirements. The alveoli are the niche of the most active lipid metabolic cell in the lung, the type 2 cell (T2C). T2C synthesize surfactant lipids that are an absolute requirement for respiration, including dipalmitoylphosphatidylcholine. After its synthesis and secretion into the alveoli, surfactant is recycled by the T2C or degraded by the alveolar macrophages (AM). Surfactant biosynthesis and recycling is tightly regulated, and dysregulation of this pathway occurs in many pulmonary disease processes. Alveolar lipids can participate in the development of pulmonary disease from their extracellular location in the lumen of the alveoli, and from their intracellular location in T2C or AM. External insults like smoke and pollution can disturb surfactant homeostasis and result in either surfactant insufficiency or accumulation. But disruption of surfactant homeostasis is also observed in many chronic adult diseases, including chronic obstructive pulmonary disease (COPD), and others. Sustained damage to the T2C is one of the postulated causes of idiopathic pulmonary fibrosis (IPF), and surfactant homeostasis is disrupted during fibrotic conditions. Similarly, surfactant homeostasis is impacted during acute respiratory distress syndrome (ARDS) and infections. Bioactive lipids like eicosanoids and sphingolipids also participate in chronic lung disease and in respiratory infections. We review the most recent knowledge on alveolar lipids and their essential metabolic and signaling functions during homeostasis and during some of the most commonly observed pulmonary diseases.

A Case of Amiodarone Pulmonary Toxicity with Short-term Amiodarone Use

This is the case of a 92-year-old female who was hospitalized one month prior to admission for symptomatic paroxysmal atrial fibrillation, requiring intravenous amiodarone. Following her previous admission, she was placed on one month of amiodarone 200 mg twice daily, with a one week transition to 200 mg daily. The patient subsequently developed progressive shortness of breath and dry cough over a period of several weeks. Initial imaging showed diffuse bilateral coarse patchy interstitial infiltration on chest X-ray and bibasilar pleural effusions and scattered bilateral opacities on CTA chest. In an elderly patient presenting with dyspnea and dry cough, as well as interstitial opacities on imaging, amiodarone pulmonary toxicity should be considered despite short-term low-dose use.

Amiodarone-induced pulmonary toxicity with an excellent response to treatment: A case report

Amiodarone is an anti-arrhythmic drug widely used, but its administration can be associated with several adverse side-effects. Among these, amiodarone-induced pulmonary toxicity (APT) occurs in 4–17% of cases and, if not early diagnosed and treated, may evolve towards pulmonary fibrosis and respiratory failure.

A 76 years-old-man went to the hospital for accidental trauma. The patient did not report respiratory symptoms but was suffering from atrial fibrillation treated with amiodarone 200 mg/day from three years (cumulative dose >150 gr). HRCT showed ground-glass opacities and nodules in both lungs. The patient underwent fibreoptic bronchoscopy with BAL. Cytologic examination of BALF sediment put in evidence foamy macrophages. The electronic microscopy revealed into the alveolar macrophages “… the presence of multilamellar intracytoplasmic bodies and lysosomes, loads of lipid material”. LFTs showed a restrictive syndrome and an impairment of DLCO. Amiodarone discontinuation and steroid administration led to the regression of radiological lesions and the recovery of lung function.

Patients taking amiodarone can experience APT. They should perform a basal chest x-ray with LFTs before starting therapy. Monitoring could reveal early the pulmonary toxicity, and patients can respond favourably to the treatment.

Amiodarone in the aged

Amiodarone is a highly effective antiarrhythmic drug, but can have serious adverse effects, particularly in older patients. If possible it should not be used purely for controlling the heart rate

If a prescription for amiodarone is contemplated, particularly for an older patient, consult a cardiologist. Avoid amiodarone in patients with significant conduction system disease, significant liver or pulmonary disease, or hyperthyroidism

Regular monitoring of the patient, clinically and biochemically, is required to identify complications at an early, treatable stage. Maintain a high level of suspicion if a patient taking amiodarone is experiencing adverse reactions and presents with new symptoms

Consider potential drug interactions when other drugs are prescribed with amiodarone. The effects and toxicities of amiodarone may persist weeks after it is stopped

Efficacy and safety of 1C class antiarrhythmic agent (propafenone) for supraventricular arrhythmias in septic shock compared to amiodarone: protocol of a prospective randomised double-blind study

INTRODUCTION

Supraventricular arrhythmias contribute to haemodynamic compromise in septic shock. A retrospective study generated the hypothesis that propafenone could be more effective than amiodarone in achieving and maintaining sinus rhythm (SR). Certain echocardiographic parameters may predict a successful cardioversion and help in the decision on rhythm or rate control strategy.

METHODS AND ANALYSIS

The trial includes septic shock patients with new-onset arrhythmia, but without severe impairment of the left ventricular ejection fraction. After baseline echocardiography, the patient is randomised to receive a bolus and maintenance dose of either amiodarone or propafenone. The primary outcome is the proportion of patients that have achieved rhythm control at 24 hours after the start of the infusion. The secondary outcomes are the percentages of patients that needed rescue treatments (DC cardioversion or unblinding and crossover of the antiarrhythmics), the recurrence of arrhythmias, intensive care unit mortality, 28-day and 1-year mortality. In the posthoc analysis, we separately assess subgroups of patients with pulmonary hypertension and right ventricular dysfunction. In the exploratory part of the study, we assess whether the presence of a transmitral diastolic A wave and its higher velocity-time integral is predictive for the sustainability of mechanical SR and whether the indexed left atrial endsystolic volume is predictive of recurrent arrhythmia. Considering that the restoration of SR within 24 hours occurred in 74% of the amiodarone-treated patients and in 89% of the patients treated with propafenone, we plan to include 200 patients to have an 80% chance to demonstrate the superiority of propafenone at p=0.05.

ETHICS AND DISSEMINATION

The trial is recruiting patients according to its second protocol version approved by the University Hospital Ethical Board on the 6 October 2017 (No. 1691/16S-IV). The results will be disseminated through peer reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03029169.

Antiarrhythmic Drugs: Risks and Benefits

The narrow therapeutic window of antiarrhythmic drugs makes their use clinically challenging. A solid understanding of the mechanisms of arrhythmias and how antiarrhythmics affect these mechanisms is only a preliminary step in their appropriate selection. Clinical factors, side-effect profiles, and proarrhythmic risks are more important than the cellular mechanisms of actions in drug selection and monitoring. This article provides a simplified approach to understanding cellular mechanisms and provides a practical approach to the selection and use of this important class of medications.

Severe and Fatal Multilobar Nonclassic Radiation Pneumonitis following Stereotactic Body Radiation Therapy (SBRT) for Treatment of Inoperable Non-Small-Cell Lung Cancer: A Report of Two Cases and Possible Enhancement by Concurrent Amiodarone

Stereotactic body radiation therapy (SBRT) is considered the standard of care for treatment of inoperable early stage non-small cell carcinoma of the lung. SBRT delivers a very high dose of ionizing radiation to a relatively small region encompassing the tumor and spares a significant portion of the remaining lung from high doses. However, the conformal high dose comes at the expense of treating a larger volume of normal lung to lower doses. In general, this has been deemed to be acceptable with an overall lower risk of radiation pneumonitis. However, in the face of predisposing factors, the higher doses delivered by this technique may lead to an increase in radiation pneumonitis. We report on two patients being treated with SBRT in which severe radiation pneumonitis developed in spite of our radiation dosimetry being significantly below the acceptable limit for lung toxicity. Both patients developed a “fulminant” form of radiation pneumonitis with radiographic abnormalities well beyond the treated volume. In one patient, the disease proved fatal. Both patients were on amiodarone at the time SBRT was administered. Given the rarity of fulminant radiation pneumonitis, especially with the relatively small fields treated by SBRT, we suspect that amiodarone enhanced the pulmonary toxicity.

Amiodarone-induced Hemoptysis: A Rare Presentation of Amiodarone-induced Pulmonary Toxicity Occurs at a Low Dose

Amiodarone-induced pulmonary toxicity (APT) is one of the most feared and underappreciated adverse effects of this commonly prescribed antiarrhythmic. APT has a variable presentation, among the rarest of these is amiodarone-induced diffuse alveolar hemorrhage with hemoptysis. Though previous cases confirmed with biopsy averaged a dose of 570 mg PO daily, APT can occur at any dose. Previous literature has suggested the importance of cumulative exposure to amiodarone rather than the patient's actual dose. The presented case describes amiodarone-induced hemoptysis occurring at a dose of 200 mg PO daily for five years. Additionally described is the treatment regimen which managed a patient with metabolic syndrome and elevated A1c while addressing the recommended treatment of extended high-dose steroids for APT with complicated respiratory status. To the best of the authors' knowledge, only two biopsied cases have been described at a dose this low. Furthermore, this case describes a more typical timeline for APT than those two cases.

Comparison of Oral, Intranasal and Aerosol Administration of Amiodarone in Rats as a Model of Pulmonary Phospholipidosis

‘Foamy’ alveolar macrophages (FAM) observed in nonclinical toxicology studies during inhaled drug development may indicate drug-induced phospholipidosis, but can also derive from adaptive non-adverse mechanisms. Orally administered amiodarone is currently used as a model of pulmonary phospholipidosis and it was hypothesized that aerosol administration would produce phospholipidosis-induced FAM that could be characterized and used in comparative inhalation toxicology. Han-Wistar rats were given amiodarone via (1) intranasal administration (6.25 mg/kg) on two days, (2) aerosol administration (3 mg/kg) on two days, (3) aerosol administration (10 mg/kg) followed by three days of 30 mg/kg or (4) oral administration (100 mg/kg) for 7 days. Alveolar macrophages in bronchoalveolar lavage were evaluated by differential cell counting and high content fluorescence imaging. Histopathology and mass-spectrometry imaging (MSI) were performed on lung slices. The higher dose aerosolised amiodarone caused transient pulmonary inflammation (p < 0.05), but only oral amiodarone resulted in FAM (p < 0.001). MSI of the lungs of orally treated rats revealed a homogenous distribution of amiodarone and a putative phospholipidosis marker, di-22:6 bis-monoacylglycerol, throughout lung tissue whereas aerosol administration resulted in localization of both compounds around the airway lumen. Thus, unlike oral administration, aerosolised amiodarone failed to produce the expected FAM responses.

Eosinophilic pneumonia: A rare manifestation of amiodarone toxicity diagnosed using traditional bronchoscopy

Amiodarone is an antiarrhythmic agent used primarily to treat atrial and ventricular arrhythmias. However, the drug also has many adverse effects, including pulmonary toxicity, and a wide range of pulmonary diseases have been reported. Amiodarone-induced eosinophilic pneumonia is a relatively rare adverse effect with an incidence ranging between 5 and 13% [1]. The majority of cases have been diagnosed with lung biopsy, with only one prior reported case diagnosed by bronchoalveolar lavage (BAL) [2]. This report describes the second documented case of amiodarone-induced eosinophilic pneumonia diagnosed by eosinophilia on BAL cytology. In this case, complete cessation of symptoms occurred after discontinuation of amiodarone and treatment with corticosteroids. An updated review of the literature of amiodarone-induced eosinophilic pneumonia is also detailed.

Maternal monitoring and safety considerations during antiarrhythmic treatment for fetal supraventricular tachycardia

Fetal tachycardia is a rare complication during pregnancy. After exclusion of maternal and fetal conditions that can result in a secondary fetal tachycardia, supraventricular tachycardia is the most common cause of a primary sustained fetal tachyarrhythmia. In cases of sustained fetal supraventricular tachycardia, maternal administration of digoxin, flecainide, sotalol, and more rarely amiodarone, is considered. As these medications have the potential to cause significant adverse effects, we sought to examine maternal safety during transplacental treatment of fetal supraventricular tachycardia. In this narrative review we summarize the literature addressing pharmacologic properties, monitoring, and adverse reactions associated with medications most commonly prescribed for transplacental therapy of fetal supraventricular tachycardia. We also describe maternal monitoring practices and adverse events currently reported in the literature. In light of our findings, we provide clinicians with a suggested maternal monitoring protocol aimed at optimizing safety.

Amiodarone induces cell proliferation and myofibroblast differentiation via ERK1/2 and p38 MAPK signaling in fibroblasts

Amiodarone is a potent antidysrhythmic agent that can cause potentially life-threatening pulmonary fibrosis. Accumulating evidence has demonstrated that myofibroblast differentiation is related to the pathogenesis of pulmonary fibrosis. In the present study, we treated human embryonic lung fibroblasts (HELFs) with amiodarone, and investigated the relative molecular mechanism of amiodarone-induced pulmonary fibrosis and pathway determinants PD98059 (extracellular signal-regulated kinase (ERK) inhibitor) and SB203580 (p38 mitogen-activated protein kinase (MAPK) inhibitor). Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8). The secretion of collagen Ⅰ was detected by ELISA. The expressions of α-smooth muscle actin (α-SMA), vimentin, phosphorylated ERK1/2 (p-ERK1/2), ERK1/2, phosphorylated p38 MAPK (p-p38), and p38 MAPK were investigated using Western blot analysis. The levels of α-SMA and vimentin were also determined by immunofluorescence and qRT-PCR. We report that amiodarone promoted cell proliferation and collagen Ⅰ secretion, induced α-SMA and vimentin protein and mRNA expression accompanied by increased phosphorylation of ERK1/2 and p38 MAPK, and furthermore, PD98059 and SB203580 remarkably reduced the proliferative response of HELFs compared with amiodarone group and greatly attenuated α-SMA, vimentin and collagen Ⅰ protein production induced by amiodarone. Taken together, our study suggests that amiodarone regulates cell proliferation and myofibroblast differentiation in HELFs through modulating ERK1/2 and p38 MAPK pathways, and these signal pathways may therefore represent an attractive treatment modality in amiodarone-induced pulmonary fibrosis.

A rare case of lipoid pneumonia attributed to amiodarone

We report a case of endogenous lipoid pneumonia secondary to long-term use of amiodarone (> 30 years) for atrial fibrillation in a 76-year-old Caucasian woman, presenting with cough and dyspnea. Endogenous Lipoid pneumonia is a rare underdiagnosed condition more prevalent in adults. It is usually asymptomatic and a diagnosis is generally made in patients who have become clinically unstable or when an abnormal lung shadow is found on a chest X-ray. In the case here described it was diagnosed by fiberoptic bronchoscopy with bronchoalveolar lavage (BALF) where fat-laden macrophages (oil red O stain) were identified. Since a history of use of oil-based products had been ruled out, amiodarone was deemed to be the most likely cause of lipoid pneumonia. The patient was managed with the replacement of amiodarone with digoxin and treated with oral prednisolone. The patient has remained clinically stable with radiological improvement during a follow-up of two years.

Adsorption and Leachable Contamination of Flucloxacillin, Cyclosporin and Amiodarone Following Delivery Through an Intravenous Administration Set

PURPOSE

Interactions between a pharmaceutical drug and its delivery device can result in changes in drug concentration and leachable contamination. Flucloxacillin, amiodarone and cyclosporin were investigated for drug concentration changes and leachable contamination after delivery through an intravenous administration set.

METHODS

Flucloxacillin, amiodarone and cyclosporin were delivered through an intravenous administration set and the eluate analysed by HPLC-UV and HPLC-MS.

RESULTS

The average recovery of flucloxacillin was 99.7% and no leachable compounds were identified. The average recovery of cyclosporin was 96.1%, which contrasts previous findings that have reported up to 50% loss of cyclosporin. This is likely due to the use of DEHP-free administration sets in this study, as adsorption of cyclosporin is linearly related to DEHP content. The average recovery of amiodarone was 91.5%. 5-hydroxymethylfurfural was identified in the amiodarone solution following delivery through the administration set as well as the 5% glucose solution used for delivery.

CONCLUSIONS

Drug/administration set interactions may modify pharmaceuticals during delivery. In this study, only 90% of the amiodarone was delivered through a generic administration set. Given the growing use of generic administration sets in hospital settings, validation of the suitability of their use is required to ensure patient safety and expected levels of efficacy.

Drug-induced eosinophilic pneumonia: A review of 196 case reports

BACKGROUND AND OBJECTIVE

Eosinophilic pneumonia (EP) is an important subset of patients who present with pulmonary infiltrates and eosinophilia (PIE). EP is classified by chronicity and etiology and drug-induced EP is the main cause of secondary EP. The primary goal of this review was to examine all the case reports published since the syndrome was defined in 1990. It remains unclear whether acute or chronic EP (AEP or CEP) represent different diseases, and the secondary goal of this review is to determine if there are factors that may help distinguish these 2 entities.

METHODS

PubMed (MEDLINE and Medical Subject Headings) was searched for case reports of drug-induced EP or PIE syndrome published between 1990 and 2017. Case reports were only included if the diagnostic criteria for AEP or CEP were fulfilled. For each case, data were extracted pertaining to age, sex, type of medication associated with the disease, time from the onset of symptoms to diagnosis, eosinophil counts in the blood, eosinophil fractions in bronchoalveolar lavage (BAL) fluid, initial chest radiograph and computed tomography results, use of mechanical ventilation, and use of steroid treatment and recurrence.

RESULTS

We found 196 case reports describing drug-induced EP. The leading cause was daptomycin. From our review, we found that AEP is more common in younger patients with no gender preference. Eosinophilia in the blood at the time of diagnosis characterized only the CEP patients (80% in CEP vs. 20% in AEP). Abnormal findings on radiographic imagine was similar in both syndromes. A significant portion of AEP patients (20%) presented with acute respiratory failure requiring mechanical ventilation. Most patients with EP were treated with steroids with a higher rate of relapse observed in patients with CEP.

CONCLUSION

AEP is a much more fulminant and severe disease than the gradual onset and slowly progressive nature of CEP. The pathogenesis of AEP and CEP remains unclear. However, there is significant clinical overlap among AEP and CEP that are associated with drug toxicity, suggesting the possibility that AEP and CEP are distinct clinical presentations that share a common pathogenic pathway.

Modeling of Amiodarone Effect on Heart Rate Control in Critically Ill Patients with Atrial Tachyarrhythmias

AIMS

Amiodarone is the gold-standard medication to control heart rate in critically ill patients with atrial tachyarrhythmias (ATs); however, effective doses and covariates influencing its efficacy remain unknown. We therefore performed pharmacodynamic modeling of heart rate reduction induced by amiodarone in these patients.

METHODS AND RESULTS

This observational study included 80 consecutive severely ill patients receiving amiodarone to treat ATs. A total of 1348 time-heart rate observations with 361 amiodarone dose administrations were analyzed during a period of up to 6 days after hospital treatment initiation using a nonlinear mixed-effect model. Pretreatment with amiodarone before intensive care administration, paroxysmal versus persistent AT, catecholamine infusion, and fluid and magnesium loading were among the covariates assessed in the model. In case of paroxysmal AT in a patient not pretreated with amiodarone, a 300 mg intravenous loading dose combined with an 800 mg oral dose on the first day, followed by 800 mg/day orally for 4 days was effective in achieving a heart rate between 80 and 115 bpm within the first day, and to maintain it during the next 4 days. Corresponding doses were twice as high in patients with persistent AT. Use of intravenous magnesium (p < 0.02) and fluid loading (p < 0.02) was associated with an earlier and greater heart rate decrease, while use of dobutamine had an opposite influence (p < 0.05).

CONCLUSIONS

In critically ill patients with AT, the dose of amiodarone required to control heart rate is influenced by the type of AT and by other easily measurable conditions which may allow better individualization of amiodarone dosing.

Rapid onset of amiodarone induced pulmonary toxicity after lung lobe resection - A case report and review of recent literature

Amiodarone-induced pulmonary toxicity (APT) is a severe side effect that can lead to lung fibrosis or fatal respiratory failure. Usually APT occurs during long term therapy after administration of prolonged loading doses or high cumulative doses. We present the case of a 58 year old woman who underwent thoracic surgery with lobe resection. She developed atrial fibrillation with hemodynamic-instability on the first post-operative day. We initiated amiodarone therapy and four days later she developed respiratory failure. The pulmonary function further deteriorated showing signs of an acute respiratory distress syndrome (ARDS). We therefore started mechanical ventilation, but still the gas exchange did not improve. A computer tomography-(CT)-scan presented bilateral interstitial and alveolar infiltrations. The patient also presented with leukocytosis, elevated C-reactive protein (CRP) levels however without elevated procalcitonin (PCT) concentrations. In the tracheal secretion we only harvested foam cells, but got no evidence for pathogens causing pneumonia. We immediately started glucocorticoid therapy with prednisolone 50 mg/d for five days. Almost instantaneously the gas exchange ameliorated. We were able to wean the patient from the respirator within five days. Pulmonary infiltrations were nearly vanished in a CT-scan few days later and completely disappeared in follow up examinations. This case demonstrates a per-acute onset of APT caused by a low loading dose in association with thoracic surgery. The initiation of glucocorticoid therapy in parallel to amiodarone withdrawal led to full recovery of the patient. One should consider APT when signs of pulmonary failure occur during brief periods of amiodarone therapy especially after thoracic surgery.

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Amiodarone-induced pulmonary toxicity (APT) can develop after low dose and short term amiodarone therapy.

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The early generation of APT is supported by thoracic surgery.

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APT can cause severe adult respiratory distress syndrome, leading to respiratory failure.

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Glucocorticoid therapy ameliorates APT symptoms and can restore respiratory failure in early state.

Morphometric Characterization of Rat and Human Alveolar Macrophage Cell Models and their Response to Amiodarone using High Content Image Analysis

PURPOSE

Progress to the clinic may be delayed or prevented when vacuolated or "foamy" alveolar macrophages are observed during non-clinical inhalation toxicology assessment. The first step in developing methods to study this response in vitro is to characterize macrophage cell lines and their response to drug exposures.

METHODS

Human (U937) and rat (NR8383) cell lines and primary rat alveolar macrophages obtained by bronchoalveolar lavage were characterized using high content fluorescence imaging analysis quantification of cell viability, morphometry, and phospholipid and neutral lipid accumulation.

RESULTS

Cell health, morphology and lipid content were comparable (p < 0.05) for both cell lines and the primary macrophages in terms of vacuole number, size and lipid content. Responses to amiodarone, a known inducer of phospholipidosis, required analysis of shifts in cell population profiles (the proportion of cells with elevated vacuolation or lipid content) rather than average population data which was insensitive to the changes observed.

CONCLUSIONS

A high content image analysis assay was developed and used to provide detailed morphological characterization of rat and human alveolar-like macrophages and their response to a phospholipidosis-inducing agent. This provides a basis for development of assays to predict or understand macrophage vacuolation following inhaled drug exposure.

Pharmacological Threat to Lungs: A Case Series and Literature Review

Drug-induced organ damage stands as a prevalent yet much-neglected issue globally. Keeping in view it’s rising frequency, health care providers stand obliged to be well versed with the de-merits of the agents they prescribe. Drug therapies causing damage present with a non-specific clinical presentation, histological findings or radiology, which further elaborates on the necessity of a conscientious diagnosis. Pulmonary architecture ranging from the airways, lung parenchyma, mediastinum, pleura, pulmonary vasculature or the neuromuscular system, all can fall victim to the dreaded outcomes of this menace. In order to establish successful diagnosis, the definite temporal relation between initiation of drug therapy and the development of the respiratory symptoms needs to be drawn. The most common form of pharmacologically arising lung toxicity is drug-induced pneumonitis or interstitial lung disease. Unfortunately, there is no adequate data available to review the extensiveness of this medication-associated risk in Pakistan which further highlights the necessity of carefully monitoring this overlooked yet assessable malady. Furthermore, identification and surveillance of this drug attributed peril shall help diminish burden on healthcare resources of the country. We present three recent cases of different types of drug-induced lung damage under treatment at our University Hospital.

Class III antiarrhythmic drugs amiodarone and dronedarone impair KIR 2.1 backward trafficking

Drug‐induced ion channel trafficking disturbance can cause cardiac arrhythmias. The subcellular level at which drugs interfere in trafficking pathways is largely unknown. K_IR2.1 inward rectifier channels, largely responsible for the cardiac inward rectifier current (I_K1), are degraded in lysosomes. Amiodarone and dronedarone are class III antiarrhythmics. Chronic use of amiodarone, and to a lesser extent dronedarone, causes serious adverse effects to several organs and tissue types, including the heart. Both drugs have been described to interfere in the late‐endosome/lysosome system. Here we defined the potential interference in K_IR2.1 backward trafficking by amiodarone and dronedarone. Both drugs inhibited I_K1 in isolated rabbit ventricular cardiomyocytes at supraclinical doses only. In HK‐KWGF cells, both drugs dose‐ and time‐dependently increased K_IR2.1 expression (2.0 ± 0.2‐fold with amiodarone: 10 μM, 24 hrs; 2.3 ± 0.3‐fold with dronedarone: 5 μM, 24 hrs) and late‐endosomal/lysosomal K_IR2.1 accumulation. Increased K_IR2.1 expression level was also observed in the presence of Na_v1.5 co‐expression. Augmented K_IR2.1 protein levels and intracellular accumulation were also observed in COS‐7, END‐2, MES‐1 and EPI‐7 cells. Both drugs had no effect on K_v11.1 ion channel protein expression levels. Finally, amiodarone (73.3 ± 10.3% P < 0.05 at −120 mV, 5 μM) enhanced I_KIR2.1 upon 24‐hrs treatment, whereas dronedarone tended to increase I_KIR2.1 and it did not reach significance (43.8 ± 5.5%, P = 0.26 at −120 mV; 2 μM). We conclude that chronic amiodarone, and potentially also dronedarone, treatment can result in enhanced I_K1 by inhibiting K_IR2.1 degradation.

Amiodarone-induced loculated pleural effusion without pulmonary parenchymal involvement: A case report and literature review

Amiodarone is an extremely effective antiarrhythmic drug that is known to cause many adverse effects such as pulmonary, thyroid, and liver toxicities. Of these, pulmonary toxicity is most serious. Pulmonary toxicity can present as interstitial pneumonitis, organizing pneumonia, pulmonary nodules and masses, and very rarely pleural effusions. We present a case of a 73-year-old male who presented with progressive exertional dyspnea, nonproductive cough, generalized fatigue, and weakness. He was found to have multiorgan toxicity secondary to long-term treatment with high doses of amiodarone. This case illustrates that amiodarone may cause toxicity involving multiple organs simultaneously in patients receiving long-term therapy and represents the first reported case of amiodarone-induced loculated pleural effusion without associated lung parenchymal involvement.

The effect of long-term amiodarone administration on myocardial fibrosis and evolution of left ventricular remodeling in a porcine model of ischemic cardiomyopathy

Amiodarone is effective in suppressing arrhythmias in heart failure patients. We investigated the effect of long-term amiodarone administration on myocardial fibrosis and left ventricular (LV) remodeling in a porcine model of ischemic cardiomyopathy. Eighteen infarcted farm pigs were randomized to receive long-term amiodarone administration for 3 months (n = 9) or conventional follow-up (n = 9). Evolution of LV remodeling over 3 months post-myocardial infarction was examined at tissue level (myocyte size, myocardial fibrosis and vascular density assessed by whole-field digital histopathology), organ level (LV structure and function assessed by echocardiography), and systemic level (BNP and MMP-9 levels). Long-term administration of the standard anti-arrhythmic doses of amiodarone was not associated with adverse effects on myocardial fibrosis and other features of adverse cardiac remodeling. This favorable safety profile suggests that long-term anti-arrhythmic therapy with amiodarone warrants further clinical investigation in the subpopulation of heart failure patients with significantly increased burden of arrhythmias.

Early Amiodarone-Induced Pulmonary Toxicity after Endovascular Aneurysm Repair: A Case Report

Amiodarone is an antiarrhythmic drug that has been commonly used to treat supraventricular and ventricular arrhythmias. This drug is an iodine-containing compound that tends to accumulate in several organs, including the lungs. Especially, its main metabolically active metabolite desethylamiodarone can adversely affect many organs. A very well-known severe complication of amiodarone therapy is the amiodarone-induced pulmonary toxicity. This article presents the case study of an 82-year-old male patient with acute amiodarone-induced pulmonary toxicity. The patient underwent endovascular aneurysm repair for rapidly increasing abdominal aortic aneurysm. During the postoperative period the patient developed rapid atrial fibrillation and amiodarone therapy was initiated. Subsequently, the patient went into acute respiratory failure and was requiring high supplemental oxygen support and a chest X-ray revealed bilateral pulmonary infiltrates. During the hospital course the patient required mechanical ventilator support. With discontinuation of amiodarone, supportive therapy and steroid treatment patient symptoms significantly improved. Amiodarone-induced pulmonary toxicity must be considered in the differential diagnosis of all patients on the medication with progressive or acute respiratory symptoms. Early discontinuation of amiodarone and aggressive corticosteroid therapy should be considered as a viable treatment strategy.

Antiarrhythmic Drug Therapy for Rhythm Control in Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and affects over 33 million people worldwide. AF is associated with stroke and systemic thromboembolism, unpleasant symptoms and reduced quality of life, heart failure, and increased mortality, and treatment of AF and its complications are associated with significant cost. Antiarrhythmic drugs (AADs) can suppress AF, allowing long-term maintenance of sinus rhythm, and have the potential to relieve symptoms and reverse or prevent adverse effects associated with AF. However, large randomized controlled studies evaluating use of AADs have not demonstrated a clear benefit to maintaining sinus rhythm, and AADs often have significant limitations, including a modest rate of overall success at maintaining sinus rhythm, frequent side effects, and potentially life-threatening toxicities. Although some of the currently available AADs have been available for almost 100 years, better tolerated and more efficacious AADs have recently been developed both for long-term maintenance of sinus rhythm and for chemical cardioversion of AF to sinus rhythm. Advances in automated AF detection with cardiac implantable electronic devices have suggested that AADs might be useful for suppressing AF to allow safe discontinuation of anticoagulation in select patients who are in sinus rhythm for prolonged periods of time. AADs may also have synergistic effects with catheter ablation of AF. This review summarizes the pharmacology and clinical use of currently available AADs for treatment of AF and discusses novel AADs and future directions for rhythm control in AF.

Anti-arrhythmic medications increase non-cardiac mortality - A meta-analysis of randomized control trials

Introduction

Anti-arrhythmic medications (AAMs) are known to increase cardiac mortality significantly due to their pro-arrhythmic effects. However, the effect of AAMs on non-cardiac mortality has not been evaluated.

Methods

Trials published in English language journals from 1990 to 2015 were thoroughly retrieved by searching websites such as PubMed, Medline, Cochrane Library, and Google Scholar. Randomized controlled trials reporting non-cardiac deaths as primary or secondary outcomes were used to compare AAMs to non-arrhythmic therapy (AV nodal blocking agents, implantable cardiovascular defibrillation (ICD), or placebo). Information regarding the sample size, treatment type, baseline characteristics, and outcomes was obtained by using a standardized protocol. The fixed effect model was used to perform meta-analysis, and results were expressed in terms of odds ratio (OR) with confidence interval (CI) of 95%, inter study heterogeneity was assessed using I². Intention to treat principle was applied to extract data.

Results

Total of 18,728 patients were enrolled in 15 trials; 9359 patients received AAMs and 9369 received non-arrhythmic therapy. AAMs were associated with an increased risk of non-cardiac mortality (OR=1.30, [95% CI: 1.12, 1.50], p=0.0005, I² index=24%) and all-cause mortality (OR=1.09, [95% CI: 1.01, 1.18], p=0.04, I²=54%) as compared to non-arrhythmic therapy. There was no difference in the cardiac mortality (OR=1.01, [95% CI: 0.92, 1.11], p=0.82, I²=53%) or arrhythmic mortality (OR=1.00, [95% CI: 0.89, 1.13], p=0.94, I²=64%) between the two groups.

Conclusion

AAMs are associated with an increased risk of non-cardiac and all-cause mortality. The effect of AAMs, especially amiodarone, on non-cardiac mortality requires further evaluation.

Effects of chronic amiodarone treatment on rat testis

Amiodarone is a potent agent used to treat tachyarrhythmias, which are especially refractory to other medications, in both adults and children. Although widely used as an antiarrhythmic drug, amiodarone causes many serious adverse effects that limit its use. This study investigated the possible morphological and apoptotic effects of amiodarone on rat testes. Amiodarone was administered to male Sprague-Dawley rats at doses of 20 or 200mg/kg/day for 14 days. A histopathological examination of testicular tissue revealed the presence of inflammatory cells in the seminiferous tubule lumen together with swelling and vacuolization in the cytoplasm of some spermatogonia; these effects occured in a dose-dependent manner. Immunohistochemical staining showed evidence of apoptosis, including caspase-3, caspase-9, Bax and increased DNA fragmentation was detected via a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. In conclusion, the results show that chronic amiodarone treatment causes dose-dependent degenerative and apoptotic effects on rat testes.

Sotalol versus Amiodarone in Treatment of Atrial Fibrillation

The availability of intravenous (IV) Sotalol has equalized the treatment options since both amiodarone and sotalol are available in both IV and oral formulations. A review of the efficacy of sotalol as compared to amiodarone both for conversion of atrial fibrillation (AF) and maintenance of normal sinus rhythm (NSR) following cardiac surgery was undertaken. Standard methods of meta-analysis were employed. Full text publications of clinical trials written in English that compared the efficacy of sotalol to amiodarone were included in the analysis. For the conversion of AF to NSR, five studies were found eligible for the analysis. Two studies clinically compared sotalol to amiodarone for the maintenance of NSR after cardiac surgery. The common relative success of sotalol was 0.947 (95Cl: 0.837 to 1.071, P = 0.385), revealing essentially no differences in efficacy for conversion between amiodarone and sotalol. The average conversion rate was 47% with sotalol and 52% with amiodarone. The conversion rates were lower for persistent AF (sotalol 22% and amiodarone 27%), while greatest for recent onset AF (88% sotalol and 77% for amiodarone). The risk of developing post-operative atrial fibrillation was practically the same in both regimes, relative risk = 1.214 (95% CI: 0.815-1.808, p=0.339). In summary, sotalol and amiodarone are equally effective in AF conversion and maintenance of NSR post-cardiac surgery.

Pioglitazone-induced Pulmonary Injury in a Very Elderly Patient

An 85-year-old woman with diabetes mellitus was admitted to our hospital due to progressive dyspnea. Two months previously, pioglitazone had been newly prescribed for diabetes management. Bilateral ground-glass opacities and progressive respiratory deterioration suggested respiratory failure due to a drug-induced lung injury. With discontinuation of pioglitazone and the administration of a corticosteroid, an improvement in her respiratory condition was achieved, although sequelae remained in some areas of the lungs. Results of drug-induced lymphocyte stimulation tests were positive for pioglitazone. Resumption of other drugs did not reinduce the lung injury. Therefore, a diagnosis of pioglitazone-induced lung injury was made. Although pioglitazone-induced lung injury is very rare, clinicians should keep it in mind when pioglitazone is used.

Coadministration of Atorvastatin and Amiodarone Increases the Risk of Pulmonary Fibrosis in Rats

OBJECTIVE

The purpose of this study was to evaluate the effect of atorvastatin administration on amiodarone-induced pulmonary fibrosis in rats.

MATERIALS AND METHODS

Thirty-six male Wistar rats were randomly divided into 4 groups. The control group (CTL) received distilled water (0.3 ml intratracheally on days 0 and 2 and 0.5 ml orally from day 0 for 3 weeks). The atorvastatin group (AT), in addition to intratracheal distilled water, received 1 mg/kg of atorvastatin orally from day 0 for 3 weeks. The amiodarone group (AMI) received 2 intratracheal instillations of amiodarone (6.25 mg/kg in 0.3 ml of water) on days 0 and 2 and 0.5 ml of distilled water (like the CTL). The amiodarone plus atorvastatin group (AMI + AT) received both these drugs (same doses and methods as for the AMI and AT). After 28 days, the rate of lung fibrosis was estimated according to pathological criteria of lung sections and measurements of hydroxyproline in pieces of left lung tissue.

RESULTS

The lung hydroxyproline content was higher in the treated groups (CTL: 0.35 ± 0.017, AT: 0.38 ± 0.012, AMI: 0.375 ± 0.018 and AMI + AT: 0.38 ± 0.012 unit/mg protein), but did not reach significance when compared with the CTL (p = 0.56). Amiodarone administration significantly increased the score of pulmonary fibrosis (0.5) in comparison with the AT (0.125) and CTL (0) (p < 0.5). The combination of amiodarone and atorvastatin exacerbated the pulmonary fibrosis (1.5; p < 0.01) compared to the AMI (0.5; p < 0.001), AT (0.125) and CTL (0).

CONCLUSION

In this study, the concomitant administration of amiodarone and atorvastatin increased pulmonary fibrosis in rats.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

In Vitro Multiparameter Assay Development Strategy toward Differentiating Macrophage Responses to Inhaled Medicines

Although foamy macrophages (FMΦ) are commonly observed during nonclinical development of medicines for inhalation, there are no accepted criteria to differentiate adaptive from adverse FMΦ responses in drug safety studies. The purpose of this study was to develop a multiparameter in vitro assay strategy to differentiate and characterize different mechanisms of drug-induced FMΦ. Amiodarone, staurosporine, and poly(vinyl acetate) nanoparticles were used to induce distinct FMΦ phenotypes in J774A.1 cells, which were then compared with negative controls. Treated macrophages were evaluated for morphometry, lipid accumulation, gene expression, apoptosis, cell activation, and phagocytosis. Analysis of vacuolization (number/area vacuoles per cell) and phospholipid content revealed inducer-dependent distinctive patterns, which were confirmed by electron microscopy. In contrast to the other inducers, amiodarone increased vacuole size rather than number and resulted in phospholipid accumulation. No pronounced dysregulation of transcriptional activity or apoptosis was observed in response to sublethal concentrations of all inducers. Functionally, FMΦ induction did not affect macrophage activation by lipopolysaccharide, but it reduced phagocytic capacity, with different patterns of induction, severity, and resolution observed with the different inducers. An in vitro multiparameter assay strategy is reported that successfully differentiates and characterizes mechanisms leading to FMΦ induction by different types of agents.