From the Guidelines
Amiodarone is contraindicated in patients with severe sinus node dysfunction, second- and third-degree AV block without a pacemaker, known hypersensitivity to amiodarone or its components, cardiogenic shock, severe hepatic disease, pre-existing hyperthyroidism, and pregnancy. According to the 2015 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1, amiodarone is contraindicated in conditions associated with QT interval prolongation, inherited long QT syndrome, sinus bradycardia (except in cardiac arrest), sinus node disease (unless a pacemaker is present), severe AV conduction disturbances (unless a pacemaker is present), and decompensated heart failure or cardiomyopathy. The 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia also lists precautions for amiodarone use, including sinus or AV conduction disease (in absence of pacemaker), inflammatory lung disease, hepatic dysfunction, hypothyroidism, hyperthyroidism, peripheral neuropathy, and abnormal gait/ataxia 1. Additionally, amiodarone has numerous drug interactions that require careful monitoring and dose adjustments, particularly with warfarin, digoxin, and QT-prolonging medications.
Some key points to consider when prescribing amiodarone include:
- Monitoring for potential adverse effects such as bradycardia, QT prolongation, gastrointestinal upset, constipation, hypothyroidism, hyperthyroidism, pulmonary fibrosis, hepatic toxicity, corneal deposits, optic neuritis, peripheral neuropathy, photosensitivity, and adult respiratory distress syndrome 1
- Avoiding concomitant use with other QT-prolonging drugs, and exercising caution in patients with pulmonary disease due to the risk of potentially fatal pulmonary toxicity
- Adjusting doses of warfarin and digoxin when co-administered with amiodarone, as it can increase their levels and effects 1
- Considering alternative treatments in patients with severe hepatic disease, pre-existing hyperthyroidism, or pregnancy, due to the potential risks associated with amiodarone use.
Overall, amiodarone should be used with caution and careful monitoring in patients with certain medical conditions, and alternative treatments should be considered when possible to minimize the risk of adverse effects and interactions.
From the FDA Drug Label
CONTRAINDICATIONS Amiodarone HCl injection is contraindicated in patients with known hypersensitivity to any of the components of amiodarone HCl injection, including iodine, or in patients with cardiogenic shock, marked sinus bradycardia, and second- or third-degree AV block unless a functioning pacemaker is available.
- Contraindications for amiodarone include:
- Known hypersensitivity to any of the components of amiodarone, including iodine
- Cardiogenic shock
- Marked sinus bradycardia
- Second- or third-degree AV block unless a functioning pacemaker is available 2
From the Research
Amiodarone Contraindications
- Known hypersensitivity to iodine is listed as a contraindication to amiodarone administration 3
- However, studies suggest that allergy to iodine and iodinated contrast agents may not be a valid absolute contraindication to amiodarone administration in the inpatient setting, with an incidence of hypersensitivity reaction to amiodarone in hospitalized patients with a listed allergy to iodine or iodinated contrast agents being less than 1% 4
- Documented allergies to contrast media or shellfish should not imply that a patient is allergic to iodine, as reactions to contrast media are likely due to the high osmolar or ionic content of the dye, and the primary allergen in shellfish is tropomyosin 5
- In patients with true iodine hypersensitivity, the potential for anaphylactic or anaphylactoid reactions to amiodarone exists 5
- Amiodarone's complex pharmacokinetic profile, characterized by a large volume of distribution and a long half-life, can result in prolonged effects even after discontinuation, and side effects may include thyroid dysfunction, pulmonary fibrosis, and hepatic injury, necessitating regular follow-ups 6
- Amiodarone interacts with several drugs, including anticoagulants, which must be managed to prevent adverse effects 6, 7