Incidence of amiodarone hypersensitivity in patients with previous allergy to iodine or iodinated contrast agents.

STUDY OBJECTIVE: To determine the incidence and nature of allergic reactions to amiodarone in hospitalized patients with a listed allergy to iodine or iodinated radiocontrast agents.

DESIGN: Retrospective medical record review.

SETTING: Two academic medical centers.

PATIENTS: A total of 234 sequential hospitalized patients with a listed iodine and/or iodinated radiocontrast agent allergy who received oral or intravenous amiodarone between January 2006 and December 2010.

MEASUREMENTS AND MAIN RESULTS: Demographic and clinical data, as well as documentation of an allergic reaction to amiodarone, were collected for each patient from electronic medical records. Mean ± SD age was 69 ± 12 years, and 51% were male. Of the 234 patients, 167 (71%) had a listed previous allergy to iodinated contrast agents, 55 (24%) to iodine, and 12 (5%) to both. Patients received an average inpatient total dose of 2.9 ± 3.2 g of either oral (106 patients [45%]), intravenous (39 patients [17%]), or both oral and intravenous (89 patients [38%]) amiodarone. Only 1 (0.4%) of the 234 patients was identified as having a probable allergic reaction to amiodarone (score of 6 on the Naranjo adverse drug reaction probability scale). One additional patient receiving intravenous amiodarone experienced a rash that was determined to be caused by an antibiotic. All other patients received amiodarone without any identifiable allergic reactions.

CONCLUSION: The incidence of hypersensitivity reaction to amiodarone in hospitalized patients with a listed allergy to iodine or iodinated contrast agents was less than 1%, and all identified reactions were without long-term sequelae. Allergy to iodine and iodinated contrast agents may not be a valid absolute contraindication to amiodarone administration in the inpatient setting.