Amiodarone and Levothyroxine interaction
Amiodarone and Levothyroxine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Amiodarone (Nexterone) label · effective 2024-04-16
Thyroid Abnormalities Nexterone inhibits peripheral conversion of throxine (T4) to triiodothyronine (T3) and may cause increased T3 levels, and increased levels of inactive reverse T3 (rT3) in clinically euthyroid patients.
Monitor thyroid function prior to treatment and periodically thereafter, particularly in elderly patients, and in any patient with a history of thyroid nodules, goiter, or other thyroid dysfunction.
Manage hypothyroidism by reducing the dose of or discontinuing amiodarone and thyroid hormone supplementation.
Fetal exposure may increase the potential for adverse experiences including cardiac, thyroid, neurodevelopmental, neurological and growth effects in neonate.
The action of antithyroid drugs may be delayed in amiodarone-induced thyrotoxicosis because of substantial quantities of preformed thyroid hormones stored in the gland.
From the Levothyroxine (Levothyroxine Sodium) label · effective 2024-07-10
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.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.