Amiodarone

Patients on amiodarone require periodic thyroid function tests and pulmonary monitoring. Amiodarone causes thyroid toxicity due to its iodine content, potentially producing either hyperthyroidism or hypothyroidism progressing to destruction of thyroid function. Pulmonary toxicity is the most feared complication of amiodarone and can progress to pulmonary fibrosis, which is irreversible scarring of lung tissue. Most adverse effects from amiodarone develop after years of use rather than immediately. Amiodarone is considered a last-resort drug used only after other anti-arrhythmic agents have failed, and is not widely used in younger patients.