Darifenacin and Fluoxetine Interaction
Drug interaction information between Darifenacin and Fluoxetine.
Darifenacin and Fluoxetine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Darifenacin 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 slows down the liver's ability to break down darifenacin. This might cause a small increase in the amount of darifenacin in your system.
What To Do
No dose changes are needed when taking these medicines together.
FDA Label Information
7.2 CYP2D6 Inhibitors No dosing adjustments are recommended in the presence of CYP2D6 inhibitors (for example, paroxetine, fluoxetine, quinidine and duloxetine) [see Clinical Pharmacology (12.3) ] .
Darifenacin Also Interacts With
- Thioridazine moderate
- Flecainide moderate
- Itraconazole moderate
- Duloxetine minor
- Estradiol minor
Fluoxetine Also Interacts With
- Aspirin major
- Warfarin major
- Olanzapine major
- Pimozide major
- Thioridazine major
Frequently Asked Questions
Can I take Darifenacin and Fluoxetine together?
This is a minor interaction. No dose changes are needed when taking these medicines together.
How serious is the interaction between Darifenacin 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 Darifenacin and Fluoxetine interact?
Fluoxetine slows down the liver's ability to break down darifenacin. This might cause a small increase in the amount of darifenacin in your system.
Understanding the Darifenacin and Fluoxetine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Darifenacin belongs to the Anticholinergic (Overactive Bladder) 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 slows down the liver's ability to break down darifenacin. 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. Darifenacin 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: No dose changes are needed when taking these medicines together. 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 Darifenacin 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.