Clinical features of and effects of angiotensin system antagonists on amiodarone-induced pulmonary toxicity

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.

Acute respiratory failure on a low dose of amiodarone - is it an underdiagnosed and undertreated condition?

Amiodarone-induced pulmonary toxicity (AIPT) has a variety of presentations. Amiodarone use has been rarely associated with the development of acute respiratory failure. We present a patient with a history of paroxysmal atrial fibrillation who developed acute respiratory distress syndrome despite taking a low dose of amiodarone and having no risk or precipitating factors. The diagnosis of AIPT was made after drug discontinuation and exclusion of other potential causes. The development of acute respiratory failure due to AIPT is often underdiagnosed and undertreated. Better identification of risk factors and developing appropriate diagnostic tools for risk stratification of patients receiving amiodarone is mandatory.

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Amiodarone use is rarely associated with the development of acute respiratory failure.

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The most clinical presentation of AIPT is a subacute illness presented by the nonproductive cough, progressive dyspnoea, and low-grade fever

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The diagnosis of AIPT is often made after drug discontinuation and exclusion of other potential causes.

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Identification of risk factors and developing appropriate diagnostic tools for risk stratification of patients receiving amiodarone is mandatory

Association between renin-angiotensin system and chronic lung allograft dysfunction

Chronic lung allograft dysfunction (CLAD) is the major cause of death after lung transplantation. Angiotensin II (AngII), the main effector of the renin-angiotensin (RA) system, elicits fibrosis in both kidney and lung. We identified 6 AngII-regulated proteins (RHOB, BST1, LYPA1, GLNA, TSP1, LAMB1) increased in urine of patients with kidney allograft fibrosis. We hypothesized that RA system is active in CLAD and that AngII-regulated proteins are increased in bronchoalveolar lavage fluid (BAL) of CLAD patients.We performed immunostaining of AngII receptors (AGTR1 and AGTR2) and TSP1/GLNA in 10 CLAD lungs and 5 controls. Using mass spectrometry, we quantified peptides corresponding to AngII-regulated proteins in BAL of 40 lung transplant recipients (CLAD, stable and acute lung allograft dysfunction (ALAD)). Machine learning algorithms were developed to predict CLAD based on BAL peptide concentrations.Immunostaining demonstrated significantly more AGTR1+ cells in CLAD versus control lungs (p=0.02). TSP1 and GLNA immunostaining positively correlated with the degree of lung fibrosis (R²=0.42 and 0.57, respectively). In BAL, we noted a trend toward higher concentrations of AngII-regulated peptides in patients with CLAD at the time of bronchoscopy, and significantly higher concentrations of BST1, GLNA and RHOB peptides in patients that developed CLAD at follow-up (p<0.05). Support vector machine classifier discriminated CLAD from stable and ALAD patients at the time of bronchoscopy with AUC 0.86, and accurately predicted subsequent CLAD development (AUC 0.97).Proteins involved in the RA system are increased in CLAD lung and BAL. AngII-regulated peptides measured in BAL may accurately identify patients with CLAD and predict subsequent CLAD development.

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.

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.

Initial characteristics and outcome of hospitalized patients with amiodarone pulmonary toxicity

Amiodarone-induced pulmonary toxicity (APT) is a serious adverse event that can lead to death. The aims of our study are to determine factors associated with mortality and to describe outcome and sequelae of patients with APT.

METHODS

Forty-six patients with APT were divided into two groups according to survival at day 90 for a clinical, functional, biological and radiological comparaison. We then evaluated the evolution of 15 survivors at a median of three months [1-6 months] and/or 12 months [8-36 months].

RESULTS

Mortality of APT at day 90 was 37% (17 patients) and was linked to the speed of onset of symptoms and a high HRCT alveolar score. Angiotensin system antagonist treatment was prescribed significantly more in the survival group (p = 0.042, HR 0.34 (95% CI 0.12-0.96)). In surviving patients, dyspnea, vital capacity and HRCT alveolar score improved significantly while HRCT fibrosis score deteriorated gradually during the first six months. At the end of the study, all the surviving patients presented functional and/or radiological sequelae.

CONCLUSIONS

Severity of APT is linked to the extent and speed of onset of pulmonary damage. After the initial episode, the patients who survived improved slowly but with persistent sequelae.

Incidence and outcomes of bepridil-induced interstitial pneumonia

BACKGROUND

The incidence of bepridil-induced pulmonary toxicity, such as interstitial pneumonia, is still unknown. The aim of the present study was to evaluate the incidence of bepridil-induced pulmonary toxicity.

METHODS AND RESULTS

A total of 253 patients treated with bepridil between January 2009 and January 2011 were retrospectively evaluated. Eight out of the 222 evaluable patients (male/female: 5/3, age range: 64-97 years, average age: 80.5 years, median age: 81.0 years) showed bepridil-induced pulmonary toxicity.

CONCLUSIONS

The incidence of bepridil-induced pulmonary toxicity was 3.60% in our study population.

Protective effects of neferine on amiodarone-induced pulmonary fibrosis in mice

The effects of neferine, a bisbenzylisoquinline alkaloid extracted from the Chinese traditional medicine seed embryo of Nelumbo nucifera Gaertn, on amiodarone-induced pulmonary fibrosis in mice were evaluated. Adult Kunming mice were induced to develop pulmonary fibrosis through intratracheal instillation of amiodarone (6.25 mg/kg) on the 1st, 3rd and 5th day. Mice were treated orally with saline, neferine (20 mg/kg), prednisolone (15 mg/kg), pirfenidone (100 mg/kg) twice a day after the third amiodarone instillation. On Day 21, all the lung tissues were collected for hydroxyproline measurement and the histological examination by hematoxylin-eosin and Masson staining. All the blood sample were collected for surfactant protein-D (SP-D) levels assay, Th1/Th2 balance valuation, CD4+CD25+ regulatory T cells (Tregs) analysis by Enzyme-linked immunosorbent assay and flow cytometry. Our data showed that neferine significantly restored the significant reductions in body weights, the increased levels of lung index and hydroxyproline, the abnormal histological findings, the serum SP-D increase, the Th1/Th2 imbalance by decreasing IL-4 and increasing IFN-γ levels and the increases in the population of CD4+CD25+ Tregs associated with amiodarone instillation in mice. Similar changes were also observed in the prednisolone or pirfenidone treated mice. In conclusion, these results indicated that neferine possessed a significant inhibitory effect on amiodarone-induced pulmonary fibrosis, probably due to its properties of anti-inflammation, SP-D inhibition and restoring increased CD4+CD25+ Tregs which may modulate Th1/Th2 imbalance by suppressing Th2 response (from Th2 polarity toward a Th1 dominant response).

Pro-apoptotic effects of imatinib on PDGF-stimulated pulmonary artery smooth muscle cells from patients with idiopathic pulmonary arterial hypertension

BACKGROUND

Remodeling of the pulmonary artery by an inappropriate increase of pulmonary artery smooth muscle cells (PASMCs) is problematic in the treatment of idiopathic pulmonary arterial hypertension (IPAH). Effective treatment that achieves reverse remodeling is required. The aim of this study was to assess the pro-apoptotic effects of imatinib, a platelet-derived growth factor (PDGF)-receptor tyrosine kinase inhibitor, on PASMCs obtained from patients with IPAH.

METHODS

PASMCs were obtained from 8 patients with IPAH undergoing lung transplantation. Cellular proliferation was assessed by (3)H-thymidine incorporation. Pro-apoptotic effects of imatinib were examined using TUNEL and caspase-3,7 assays and using transmission electron microscopy.

RESULTS

Treatment with imatinib (0.1 to 10 μg/mL) significantly inhibited PDGF-BB (10 ng/mL)-induced proliferation of PASMCs from IPAH patients. Imatinib (1 μg/mL) did not induce apoptosis in quiescent IPAH-PASMCs, but it had a pro-apoptotic effect on IPAH-PASMCs stimulated with PDGF-BB. Imatinib did not induce apoptosis in normal control PASMCs with or without PDGF-BB stimulation. PDGF-BB induced phosphorylation of Akt at 15 min, and Akt phosphorylation was inhibited by imatinib in IPAH-PASMCs. Akt-I-1/2 (1 μmol/L), an Akt inhibitor, in the presence of PDGF-BB significantly increased apoptotic cells compared with the control condition. Thus, Akt-I-1/2 could mimic the effects of imatinib on PASMCs.

CONCLUSION

Imatinib has anti-proliferative and pro-apoptotic effects on IPAH-PASMCs stimulated with PDGF. The inhibitory effect of imatinib on Akt phosphorylation induced by PDGF plays an important role in the pro-apoptotic effect.

Effects of neferine on the pharmacokinetics of amiodarone in rats

Amiodarone, an iodinated benzofuran derivative with predominantly class III anti-arrhythmic effects, is used to treat supraventricular and ventricular arrhythmias. The purpose of this study was to assess the potential of neferine, an effective anti-pulmonary fibrosis drug isolated from the embryo of Nelumbo nucifera Gaertner's seeds, to alter the pharmacokinetic profile of amiodarone. Experimental Sprague-Dawley rats were randomly divided into two groups. In groups 1 and 2, amiodarone was given to rats by intragastric and intravenous administration, respectively, while neferine was co-administratered by intragastric administration. Blood samples were collected from the orbital venous plexus at indicated time points and were analyzed for amiodarone concentration using RP-HPLC. The geometric mean ratio for C(max) and AUC(0-96) was calculated. There were no significant differences between the pharmacokinetics parameters of amiodarone administered intravenously or intragastrically and the control (without neferine) group (with ratios of 0.7-1.4 in all experimental groups), suggesting that neferine had no effect on amiodarone plasma pharmacokinetics. The dosage regimen of amiodarone does not need to be taken into consideration when combined with neferine.