Fluoxetine and Ketoconazole Interaction
Drug interaction information between Fluoxetine and Ketoconazole.
Fluoxetine and Ketoconazole have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Fluoxetine and Ketoconazole. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Ketoconazole is a strong blocker of a liver enzyme that helps the body get rid of certain drugs. This can lead to higher levels of medications in your blood.
FDA Label Information
Additionally, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than fluoxetine or norfluoxetine as an inhibitor of the metabolism of several substrates for this enzyme, including astemizole, cisapride, and midazolam.
Fluoxetine Also Interacts With
- Aspirin major
- Warfarin major
- Olanzapine major
- Pimozide major
- Thioridazine major
Ketoconazole Also Interacts With
- Alfuzosin major
- Dronedarone major
- Ranolazine major
- Saxagliptin major
- Sildenafil major
Frequently Asked Questions
What SPL severity band is on file for Fluoxetine + Ketoconazole?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Ketoconazole has 113 labeled pairs on file vs Fluoxetine's 68. In the minor band specifically: Fluoxetine has 43 (also Lithium, Moxifloxacin, Erythromycin, Imipramine); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).
What mechanism field is on file for Fluoxetine and Ketoconazole?
Ketoconazole is a strong blocker of a liver enzyme that helps the body get rid of certain drugs. This can lead to higher levels of medications in your blood.
Ketoconazole's labeled portfolio outnumbers Fluoxetine
SPL source-record counts only. This page's band is minor · classes on file: Fluoxetine (Selective Serotonin Reuptake Inhibitor (SSRI)); Ketoconazole (Azole Antifungal).
6 major · 19 moderate · 43 minor · 68 total
- Other minor peers for Fluoxetine
- Lithium
- Moxifloxacin
- Erythromycin
- Imipramine
6 major · 22 moderate · 85 minor · 113 total
- Other minor peers for Ketoconazole
- Abiraterone
- Acetaminophen/Oxycodone
- Alosetron
- Amphotericin B
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.