Does Fluoxetine Interact With Ketoconazole?
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.
Severity: Minor
Severity basis: drug interactions section. Combining Fluoxetine (SSRI antidepressant) and Ketoconazole (Azole antifungal (strong CYP3A4 inhibitor)) is classified as a minor interaction.
What to Do
This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.
How This Interaction Works
Interactions like this one can happen when two medicines have overlapping effects, or when one changes how the other is absorbed, broken down, or cleared from the body. Fluoxetine is a ssri antidepressant and Ketoconazole is a azole antifungal (strong cyp3a4 inhibitor); together they are documented as a minor interaction. How much this matters depends on your dose, your other medications, and your overall health.
If You Take Both Medications
If you have been prescribed both Fluoxetine and Ketoconazole, do not start, stop, or change either medication on your own — some medicines are unsafe to stop suddenly. Tell your prescriber and pharmacist that you take both so they can decide whether the combination is right for you, adjust the dose, monitor you more closely, or suggest an alternative.
From the FDA Label
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.
Source: FDA structured product labeling (set_id 02283de9-6087-45f7-a9ce-3b082ce860de).
Ketoconazole
Azole antifungal (strong CYP3A4 inhibitor)
Brands: Nizoral
View Ketoconazole safety profileCheck these against your full medication list in our free Interaction Checker
Frequently Asked Questions
Can you take Fluoxetine and Ketoconazole together?
Fluoxetine and Ketoconazole have a documented minor interaction. This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.
How serious is the Fluoxetine and Ketoconazole interaction?
It is classified as a minor interaction, based on the FDA label's drug interactions section. A minor interaction is usually limited in effect but is still worth discussing with your care team.
What should I do if I'm taking both Fluoxetine and Ketoconazole?
If you have been prescribed both Fluoxetine and Ketoconazole, do not start, stop, or change either medication on your own — some medicines are unsafe to stop suddenly. Tell your prescriber and pharmacist that you take both so they can decide whether the combination is right for you, adjust the dose, monitor you more closely, or suggest an alternative.
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 Fluoxetine Interactions
- Fluoxetine + Olanzapine(contraindicated)
- Fluoxetine + Aspirin(major)
- Fluoxetine + Warfarin(major)
- Fluoxetine + Alprazolam(moderate)
- Fluoxetine + Aripiprazole(moderate)
- Fluoxetine + Atomoxetine(moderate)
- Fluoxetine + Buspirone(moderate)
- Fluoxetine + Carbamazepine(moderate)
- Fluoxetine + Diazepam(moderate)
- Fluoxetine + Duloxetine(moderate)
- Fluoxetine + Glimepiride(moderate)
- Fluoxetine + Insulin Aspart(moderate)
- Fluoxetine + Insulin Glargine(moderate)
- Fluoxetine + Lithium(moderate)
- Fluoxetine + Phenytoin(moderate)
- Fluoxetine + Tramadol(moderate)
- Fluoxetine + Amiodarone(minor)
- Fluoxetine + Amitriptyline(minor)
- Fluoxetine + Bupropion(minor)
- Fluoxetine + Carvedilol(minor)
- Fluoxetine + Clonazepam(minor)
- Fluoxetine + Codeine(minor)
- Fluoxetine + Metoprolol(minor)
- Fluoxetine + Risperidone(minor)
- Fluoxetine + Sertraline(minor)
- Fluoxetine + Tacrolimus(minor)
- Fluoxetine + Venlafaxine(minor)
- Fluoxetine + Zolpidem(minor)
Other Ketoconazole Interactions
- Ketoconazole + Lovastatin(contraindicated)
- Ketoconazole + Fluticasone Salmeterol(major)
- Ketoconazole + Rifampin(major)
- Ketoconazole + Rivaroxaban(major)
- Ketoconazole + Sildenafil(major)
- Ketoconazole + Tamsulosin(major)
- Ketoconazole + Ticagrelor(major)
- Ketoconazole + Alprazolam(moderate)
- Ketoconazole + Codeine(moderate)
- Ketoconazole + Eszopiclone(moderate)
- Ketoconazole + Hydrocodone Acetaminophen(moderate)
- Ketoconazole + Oxycodone(moderate)
- Ketoconazole + Phenytoin(moderate)
- Ketoconazole + Pravastatin(moderate)
- Ketoconazole + Tacrolimus(moderate)
- Ketoconazole + Tramadol(moderate)
- Ketoconazole + Zolpidem(moderate)
- Ketoconazole + Apixaban(minor)
- Ketoconazole + Atorvastatin(minor)
- Ketoconazole + Buprenorphine Naloxone(minor)
- Ketoconazole + Colchicine(minor)
- Ketoconazole + Dabigatran(minor)
- Ketoconazole + Dexamethasone(minor)
- Ketoconazole + Diazepam(minor)
- Ketoconazole + Digoxin(minor)
- Ketoconazole + Famotidine(minor)
- Ketoconazole + Itraconazole(minor)
- Ketoconazole + Lansoprazole(minor)
- Ketoconazole + Methylprednisolone(minor)
- Ketoconazole + Oxybutynin(minor)
- Ketoconazole + Pantoprazole(minor)
- Ketoconazole + Quetiapine(minor)
- Ketoconazole + Simvastatin(minor)
- Ketoconazole + Sucralfate(minor)
- Ketoconazole + Tadalafil(minor)
- Ketoconazole + Trazodone(minor)
- Ketoconazole + Venlafaxine(minor)
- Ketoconazole + Warfarin(minor)