Amiodarone‐induced pulmonary toxicity

Abstract

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • A number of factors have been hypothesized to increase the risk of amiodarone‐induced pulmonary toxicity (AIPT), although there remains some controversy in the literature as to their relative significance. • This study aimed to clarify this situation to permit better characterization of patients at risk of AIPT and thus guide the development of guidelines for the monitoring for AIPT in patients receiving the drug. WHAT THIS STUDY ADDS • Via compilation and analysis of a database of 237 AIPT cases, it was demonstrated that only patient age and duration of therapy significantly affected the risk of AIPT. • A small cohort of hospital AIPT patients demonstrated these ‘at‐risk’ characteristics, suggesting that targeted monitoring of patients aged >60 years and those on amiodarone for 6–12 months may enhance the safety of these patients and minimize their risk of morbidity and mortality secondary to AIPT. AIMS A number of factors have been hypothesized to increase the risk of amiodarone‐induced pulmonary toxicity (AIPT). This study aimed to confirm these risk factors and determine whether a cohort of tertiary hospital patients diagnosed with AIPT demonstrated comparable characteristics. METHODS Phase I of this study involved compilation of a database of adverse reactions to amiodarone reported to the Australian and US drug agencies, and identification of risk factors for AIPT using logistic regression analysis. In Phase II, AIPT cases were identified via a retrospective review of medical records of patients discharged from Fremantle Hospital and Health Service, Western Australia (FHHS) between 2000 and 2005 with diagnosed interstitial lung disease. Data were collected regarding these patients’ risk factors for AIPT and compared with those previously identified in Phase I. RESULTS A total of 237 cases of AIPT were identified from agency data. Patients aged > 60 years and those on amiodarone for 6–12 months (odds ratio 18.28, 95% confidence interval 6.42, 52.04) were determined to be at the highest risk of AIPT. Australian data also suggested increased risk in patients who had received cumulative doses of 101–150 g. The seven AIPT cases identified among the FHHS patients were all at high risk of AIPT based on their age and duration of amiodarone therapy. CONCLUSION Contrary to previous findings, only patient age and the duration of amiodarone therapy were confirmed as significant risk factors for AIPT. Targeted monitoring of these patients may facilitate early identification and management of AIPT.

Amiodarone Induced Organizing Pneumonia: A Masquerader of Community Acquired Pneumonia

“…Risk factors for APT have been suggested such as daily dose, cumulative dose, duration of therapy, patient age and the presence of pre-existing lung disease [3,5,11], but this is not consensual and more investigation is needed in order to define which risk factors are preponderant in development of AIPT to identify the patients at greater risk needing closest monitoring. D.K.…”

“…D.K. Ernawati et al tested the first four in a large database, and only patient age and duration of amiodarone therapy were confirmed as significant risk factors [3].…”

“…After the introduction of amiodarone as an antiarrytmic in 1967, pulmonary toxicity was first described in 1980 [6] and has been reported in some series as the third most common reaction [3], being among the most severe [5]. It is present in 5-10% of patients taking amiodarone [5][6][7][8] and it can occur at any dose, even with low dose therapy [9].…”

“…Amiodarone is one of the most common antiarrhythmic medications prescribed worldwide [1] and its adverse reactions are very frequent (75% of patients) [2] and extensively studied: corneal deposits in over 90% of the patients (and also development of cataract and optic neuropathy), interaction with other cardiac drugs, symptomatic bradycardia, hepatotoxicity, gastrointestinal disturbances, dermatitis, bluish discoloration of the skin, bone marrow suppression, coagulopathies, peripheral neuropathies, hyperthyroidism and hypothyroidism, being thyroid dysfunction the predominant one [1,[3][4][5].…”

An Underestimated Cause of Dyspnea in an Emergency Setting: “Amiodarone Lung”. A Case Report and Review of the Literature

“…Age is one of the most important risk factors for amiodaroneinduced pulmonary side effects, that increases 3-fold every 10 years of age in patients aged >60 years compared with those aged <60 years [11]. Through its lipophilic distribution, amiodarone concentrates in organs with high lipid content such as adipose tissue, thyroid, liver and lung [12].…”