Assistant Professor Eastern Virginia Medical School, United States
Introduction: Pulmonary toxicity is a rare but severe side effect associated with amiodarone use. When present, it often manifests as interstitial pneumonia or organizing pneumonia, and rarely as eosinophilic pneumonia. Symptom-onset is typically months to years after initiation of the drug. Here we present a case of amiodarone-induced eosinophilic pneumonia that occurred just a few days after starting amiodarone.
Description: A 63-year-old Caucasian male with coronary artery disease presented to the emergency department (ED) with a productive cough and dyspnea on exertion. His symptoms started following a coronary artery bypass graft (CABG) procedure that he had about nine days prior to this encounter. He had been started on amiodarone prophylaxis prior to the CABG for arrhythmia prevention. Post-op he developed atrial fibrillation with rapid ventricular response, and required amiodarone drip with bolus to control his rate. The patient was eventually discharged seven days after the CABG procedure on daily amiodarone. Chest X-ray obtained in ED this time showed minimal left basilar subsegmental atelectasis and CT of the chest revealed bibasilar consolidation. The patient did not have leukocytosis, but he notably had eosinophilia at a maximum of 12% or absolute eosinophil count of 1K/µL.
Due to his eosinophilia and imaging findings, bronchoscopy with bronchoalveolar lavage was planned. Amiodarone was held for suspicion of associated pulmonary toxicity. BAL findings included foamy macrophages, reactive pneumocytes, and eosinophilic predominance. Bronchial culture and gram stain showed no growth. The patient was presumed to have amiodarone-induced eosinophilic pneumonia based on the BAL findings. He was initiated on prednisone 40 mg daily for seven days and had resolution of imaging findings on 2 weeks follow up.
Discussion: Amiodarone can be toxic to several organs, however, its most fatal effects are on lungs. It is commonly used in CABG procedure to prevent post-op arrhythmias. This case highlights an important association of amiodarone with rapid onset pulmonary toxicity. Low threshold for bronchoscopy is needed to make diagnosis in the appropriate clinical setting. It is important for clinicians to be aware of such cases to prevent morbidity and mortality associated with this drug.