Pulmonary effects of low dose amiodarone: a review of the risks and recommendations for surveillance.

Previous studies have reported an incidence of amiodarone-induced pulmonary toxicity (AIPT) of 5% to 10% with high doses of amiodarone (greater than 400 mg daily). A lower rate of 1.6% is recorded from combined placebo controlled, double-blind trials involving 3439 patients receiving daily amiodarone doses of 400 mg or less. Although the rate of diagnosis of AIPT appears to be lower than previously reported, it is still considerable, and its consequences are potentially fatal if undiagnosed. Before amiodarone is initiated, baseline chest x-ray (CXR) and pulmonary function tests should be performed. Although follow-up surveillance with CXR at three- to six-month intervals has been recommended, pulmonary toxicity can develop rapidly, and radiographic abnormalities may not precede clinical toxicity. Repeat lung function testing should be reserved for patients who develop new symptoms or CXR findings. Patient self-reporting of symptoms and regular clinical evaluation are likely the easiest and most useful strategies for prompt detection of AIPT.