Alendronate and Levothyroxine Interaction
Drug interaction information between Alendronate and Levothyroxine.
Alendronate and Levothyroxine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Alendronate and Levothyroxine. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Taking these two drugs at the same time can prevent the body from absorbing enough alendronate into the system.
What To Do
Talk to your doctor about timing your doses, as you may need to take these medications at different times of the day.
FDA Label Information
7.4 Levothyroxine The bioavailability of alendronate was slightly decreased when BINOSTO and levothyroxine were co-administered to healthy subjects [see Clinical Pharmacology (12.3) ] .
Levothyroxine Also Interacts With
- Sertraline minor
- Furosemide minor
- Propranolol minor
- Ferrous Sulfate minor
- Amitriptyline minor
Frequently Asked Questions
Can I take Alendronate and Levothyroxine together?
This is a minor interaction. Talk to your doctor about timing your doses, as you may need to take these medications at different times of the day.
How serious is the interaction between Alendronate and Levothyroxine?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Alendronate and Levothyroxine interact?
Taking these two drugs at the same time can prevent the body from absorbing enough alendronate into the system.
Understanding the Alendronate and Levothyroxine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Alendronate belongs to the Bisphosphonate class and Levothyroxine belongs to the Thyroid Hormone class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Taking these two drugs at the same time can prevent the body from absorbing enough alendronate into the system. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Alendronate has 2 total documented interactions on file in this dataset, and Levothyroxine has 22. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Talk to your doctor about timing your doses, as you may need to take these medications at different times of the day. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Alendronate or Levothyroxine based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.