Very Early Onset of Amiodarone-Induced Pulmonary Toxicity
A 54-year-old man was admitted to the hospital with chest pain and ST elevation myocardial infarction. He had no medical history, except for a 60 pack-year smoking history and that he was current smoker. A cardiac catheterization showed total occlusion with Thrombolysis in Myocardial Infarction 0 flow at the proximal left anterior descending artery. He had percutaneous coronary intervention with stenting at the proximal left anterior descending coronary artery. On the night of the catheterization, ventricular tachycardia developed. He was electrically cardioverted, which resulted in sinus rhythm, and amiodarone therapy was started at an initial loading dose of 150 mg intravenously (i.v.), followed by a daily dose of 730 mg i.v. for 2 days. A transthoracic echocardiogram demonstrated anterior and anteroseptal hypokinesis of the left ventricle with an ejection fraction of 35%. After 2 days of amiodarone therapy - a total of 1635 mg of amiodarone - low-grade fever developed with mild dyspnea. Pulse oximetry was 88% in oxygen saturation on room air. Compared with the initial chest X-ray finding, a follow-up chest radiography demonstrated bilateral diffuse infiltration (). Blood tests showed a leukocyte count of 15800/mm3 and a serum creatinine value of 1.2 mg/dL. Pneumonia was suspected and intravenous therapy with piperacillin, tazobactam and levofloxacin was started. The results of blood and sputum culture were negative. Gram's stain and a smear for tuberculosis organisms were also negative, as were serologic tests for Legionella and Chlamydia trachomatis. Mycoplasma pneumoniae polymerase chain reaction tests were also negative. Values for antinuclear antibody, double-stranded deoxyribonucleic acid antibodies, rheumatoid factor, as well as C'3 and C'4 were all within normal limits. Pulmonary edema was also suspected and intravenous diuretics therapy (Lasix 100 mg/day for 3 days) was started; however, no interval change was noted on chest radiography after 3 kg of weight loss. A high resolution computed tomography scan of the chest showed bilateral diffuse consolidation, ground glass opacity and underlying emphysema (). Owing to a high suspicion of amiodarone pulmonary toxicity (APT), amiodarone was discontinued after a total dose of 4035 mg over more than 8 days. Steroid therapy was not started due to mild respiratory symptoms. Pulmonary function tests showed mild obstructive impairment and carbon monoxide diffusing capacity (DLCO) was checked as 16.1 L (79%). As the clinical status was stabilized, bronchoscopy was performed. Bronchoalveolar lavage revealed a cell count of 200 cells/µL with prominent eosinophilia (8%) and foamy macrophages (). No bacteria or fungi were identified via microscopic examination or culture of the lavage fluid. Ten days after amiodarone was discontinued, the patient was discharged with mild dyspnea. Three months later, APT appeared to be reversible with the resolution of chest radiography findings () and recovery of symptoms.