Lung Disease Caused by Amiodarone, a New Antiarrythmic Agent

Amiodarone hydrochloride, used for prophylaxis of recurrent ventricular tachyarrhythmias that are resistant to other agents, may cause toxic pulmonary reactions associated with abnormal chest radiographs. The authors review four new cases of amiodarone-induced toxicity and eight cases reported in the literature. Peripheral areas of consolidation, predominantly in the upper lobes and resembling chronic eosinophilic pneumonia or tuberculosis, and diffuse interstitial disease were seen. Clinical symptoms included dyspnea on exertion, weakness, and occasionally pleuritic pain. Radiographic abnormalities developed after a median latency period of six months on the drug (600 to 800 mg daily). Pathologic findings suggested a possible toxic effect of the drug on phospholipid metabolism in the lung. Amiodarone toxicity may lead to significant pulmonary insufficiency. The clinical symptoms and radiographic abnormalities were completely reversible upon cessation of drug use and institution of corticosteroid treatment. Resolution generally occurs within three months.