To the Editor.
—The excellent Special Communication by Dr Singer and colleagues1 gives guidelines for use by physicians in the care of patients with thyroid disorders. However, I was surprised that Singer et al did not mention the role of amiodarone in causing thyroid disorder.2,3 Amiodarone is an iodinated molecule containing 37.2% of its molecular weight as iodine; therefore, it may cause thyroid dysfunction. Amiodarone has been reported to cause both thyrotoxicosis and hypothyroidism.2,3 Middlekauf et al4 published an excellent review of amiodarone therapy in patients with atrial fibrillation. Amiodarone therapy is being used widely for treatment of atrial fibrillation and congestive heart failure.5Amiodarone therapy should have been added to the guidelines so that physicians may be made aware of this iatrogenic thyroid disorder.
Ahmad S. Treatment Guidelines for Hyperthyroidism and Hypothyroidism. JAMA. 1995;274(13):1011. doi:10.1001/jama.1995.03530130017007