Diagnosis of Amiodarone Pulmonary Toxicity with HighResolution Computerized Tomographic Scan

INTRODUCTION: Amiodarone pulmonary toxicity is a serious adverse effect that can be fatal. The diagnosis is difficult due to the nonspecificity of symptoms, clinical findings, and test results. Because of its high iodine content, amiodarone deposition can be detected by sensitive high-resolution computed tomographic (CT) scan techniques. We hypothesized that pulmonary toxicity can be diagnosed more readily when these scans indicate the presence of increased attenuation of either pleural or pulmonary densities representing high iodine amiodarone deposits. METHODS AND RESULTS: This case control study included 16 patients taking chronic amiodarone. Eight cases presented with severe respiratory and other symptoms and were matched with 8 controls, 4 with mild or chronic respiratory symptoms. All patients underwent high-resolution CT of the chest. All cases had positive CT scan results demonstrating bilateral air-space disease, parenchymal bands, and thickened septal and bronchiolitis obliterans. All minimally or asymptomatic patients had negative scans with no area of high attenuation. All cases had > or = 1 lesion with high-attenuation density. The cases were treated successfully by supportive care, discontinuation of amiodarone, and, rarely, corticosteroid therapy. Two cases had delayed diagnosis of amiodarone pulmonary toxicity and were managed successfully only after CT. CONCLUSION: High-resolution CT may be a valuable noninvasive test to aid in the diagnosis of amiodarone pulmonary toxicity in symptomatic patients.