Does Amitriptyline Interact With Levothyroxine?
7.5 Antidepressant Therapy Concurrent use of tricyclic (e.g., amitriptyline) or tetracyclic (e.g., maprotiline) antidepressants and levothyroxine sodium may increase the therapeutic and toxic effects of both drugs, possibly due to increased receptor sensitivity to catecholamines.
Severity: Moderate
Severity basis: drug interactions section (keywords: may increase). Combining Amitriptyline (Tricyclic antidepressant) and Levothyroxine (Thyroid hormone) is classified as a moderate interaction.
What to Do
Use this combination with caution. Your prescriber may monitor you more closely or adjust doses.
From the FDA Label
7.5 Antidepressant Therapy Concurrent use of tricyclic (e.g., amitriptyline) or tetracyclic (e.g., maprotiline) antidepressants and levothyroxine sodium may increase the therapeutic and toxic effects of both drugs, possibly due to increased receptor sensitivity to catecholamines.
Source: FDA structured product labeling (set_id 008de8fd-150f-4022-8ccb-c8bfa94875c7).
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 It may be incomplete or out of date, and individual circumstances vary.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.
Other Amitriptyline Interactions
- Amitriptyline + Risperidone(major)
- Amitriptyline + Carbamazepine(moderate)
- Amitriptyline + Cyclobenzaprine(moderate)
- Amitriptyline + Duloxetine(moderate)
- Amitriptyline + Liothyronine(moderate)
- Amitriptyline + Valproic Acid(moderate)
- Amitriptyline + Clonidine(minor)
- Amitriptyline + Fluconazole(minor)
- Amitriptyline + Fluoxetine(minor)
- Amitriptyline + Paroxetine(minor)
- Amitriptyline + Sertraline(minor)
- Amitriptyline + Topiramate(minor)
Other Levothyroxine Interactions
- Levothyroxine + Carbamazepine(moderate)
- Levothyroxine + Dexamethasone(moderate)
- Levothyroxine + Alendronate(minor)
- Levothyroxine + Amiodarone(minor)
- Levothyroxine + Aspirin(minor)
- Levothyroxine + Ferrous Sulfate(minor)
- Levothyroxine + Furosemide(minor)
- Levothyroxine + Liothyronine(minor)
- Levothyroxine + Nifedipine(minor)
- Levothyroxine + Phenytoin(minor)
- Levothyroxine + Propranolol(minor)
- Levothyroxine + Rifampin(minor)
- Levothyroxine + Semaglutide(minor)
- Levothyroxine + Sertraline(minor)
- Levothyroxine + Sucralfate(minor)