Does Amiodarone Interact With Levothyroxine?

Other drugs: Amiodarone Amiodarone inhibits peripheral conversion of levothyroxine (T4) to triiodothyronine (T3) and may cause isolated biochemical changes (increase in serum free-T4, and decreased or normal free-T3) in clinically euthyroid patients.

Severity: Minor

Severity basis: drug interactions section. Combining Amiodarone (Class III antiarrhythmic) and Levothyroxine (Thyroid hormone) is classified as a minor interaction.

What to Do

This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.

From the FDA Label

Other drugs: Amiodarone Amiodarone inhibits peripheral conversion of levothyroxine (T4) to triiodothyronine (T3) and may cause isolated biochemical changes (increase in serum free-T4, and decreased or normal free-T3) in clinically euthyroid patients.

Source: FDA structured product labeling (set_id 008de8fd-150f-4022-8ccb-c8bfa94875c7).

Amiodarone

Class III antiarrhythmic

Brands: Pacerone, Cordarone

View Amiodarone safety profile

Levothyroxine

Thyroid hormone

Brands: Synthroid, Levoxyl, Euthyrox

View Levothyroxine safety profile

Check these against your full medication list in our free Interaction Checker

This information is educational — not medical advice.

This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.

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