Metoprolol and Fluoxetine Interaction
Drug interaction information between Metoprolol and Fluoxetine.
Metoprolol and Fluoxetine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Metoprolol and Fluoxetine. 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
Fluoxetine blocks the liver from breaking down metoprolol, which can cause the amount of metoprolol in your blood to double.
What To Do
Your doctor may need to lower your metoprolol dose and monitor your heart rate closely.
FDA Label Information
7.3 CYP2D6 Inhibitors Drugs that are strong inhibitors of CYP2D6 such as quinidine, fluoxetine, paroxetine, and propafenone were shown to double metoprolol concentrations.
Metoprolol Also Interacts With
- Theophylline major
- Clonidine moderate
- Diltiazem moderate
- Verapamil moderate
- Paroxetine minor
Fluoxetine Also Interacts With
- Aspirin major
- Warfarin major
- Olanzapine major
- Pimozide major
- Thioridazine major
Frequently Asked Questions
Can I take Metoprolol and Fluoxetine together?
This is a minor interaction. Your doctor may need to lower your metoprolol dose and monitor your heart rate closely.
How serious is the interaction between Metoprolol and Fluoxetine?
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 Metoprolol and Fluoxetine interact?
Fluoxetine blocks the liver from breaking down metoprolol, which can cause the amount of metoprolol in your blood to double.
Understanding the Metoprolol and Fluoxetine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Metoprolol belongs to the Beta-Blocker class and Fluoxetine belongs to the Selective Serotonin Reuptake Inhibitor (SSRI) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Fluoxetine blocks the liver from breaking down metoprolol, which can cause the amount of metoprolol in your blood to double. 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. Metoprolol has 18 total documented interactions on file in this dataset, and Fluoxetine has 68. 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: Your doctor may need to lower your metoprolol dose and monitor your heart rate closely. 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 Metoprolol or Fluoxetine 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.