Lung - nontumor
Other interstitial pneumonitis / fibrosis
Amiodarone induced pulmonary toxicity

Topic Completed: 1 September 2011

Revised: 30 January 2019, last major update September 2011

Copyright: (c) 2003-2017,, Inc.

PubMed search: amiodarone pulmonary toxicity

Elliot Weisenberg, M.D.
Page views in 2019: 941
Page views in 2020 to date: 452
Cite this page: Weisenberg E. Amiodarone induced pulmonary toxicity. website. Accessed May 31st, 2020.
Definition / general
  • Oral antiarrythmic drug, usually used long term
  • 5% - 10% of patients develop lung injury
  • Risk factors are: advanced age, higher dose therapy, lung surgery, oxygen therapy and underlying pulmonary disease; disease may occur without risk factors or at lower doses
  • Drug inhibits phospholipid degradation by lysosomes, resulting in phospholipid accumulation within cells, especially alveolar macrophages
Case reports
  • Drug withdrawal or dose reduction, corticosteroid therapy
  • May have 50% mortality if diffuse alveolar damage is present
Microscopic (histologic) description
  • Intra-alveolar exudate of finely vacuolated foamy macrophages, also present within alveolar septa
  • May have diffuse alveolar damage, cryptogenic organizing pneumonia type changes or changes of nonspecific interstitial pneumonia or desquamative interstitial pneumonia
Microscopic (histologic) images

Images hosted on other servers:

Various images

Cytology description
  • Finely vacuolated, foamy macrophages; variable neutrophils
Electron microscopy description
  • Membrane bound cytoplasmic lamellar inclusions due to drug accumulation in the lungs
  • Morphologic findings are not specific and must be interpreted in conjunction with the clinical history
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