Amiodarone pulmonary toxicity. Clinical, radiologic, and pathologic correlations.

Area of Science:

• Pulmonology
• Toxicology
• Pathology

Background:

• Amiodarone is a widely used antiarrhythmic drug.
• Pulmonary toxicity is a known adverse effect of amiodarone.
• Distinguishing amiodarone-induced lung injury from other conditions can be challenging.

Purpose of the Study:

• To characterize the clinical, radiographic, and pathologic features of amiodarone pulmonary toxicity.
• To compare these features in patients with and without toxic effects.
• To evaluate the diagnostic utility of specific pathologic findings.

Main Methods:

• Retrospective study of 15 patients with amiodarone pulmonary toxicity and 5 controls.
• Review of clinical presentations, chest roentgenograms, and pathologic findings (including electron microscopy).

Main Results:

• Six of 15 toxic patients presented with acute illness resembling infection.
• Radiographic findings included diffuse interstitial disease, airspace opacities, and localized infiltrates.
• Interstitial pneumonia with foamy alveolar macrophages was common, but also present in non-toxic patients.
• Lamellated inclusion bodies were found in toxic and non-toxic patients.

Conclusions:

• Amiodarone pulmonary toxicity exhibits protean manifestations and can mimic infectious diseases.
• Foamy alveolar macrophages and lamellated inclusion bodies are not reliable markers to differentiate toxic from non-toxic patients.
• Characteristic pathologic changes are often present, but require careful interpretation in the context of clinical and radiographic findings.