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.

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).

Fluoxetine

SSRI antidepressant

Brands: Prozac, Sarafem

View Fluoxetine safety profile

Ketoconazole

Azole antifungal (strong CYP3A4 inhibitor)

Brands: Nizoral

View Ketoconazole safety profile

Check these against your full medication list in our free Interaction Checker

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 It may be incomplete or out of date, and individual circumstances vary.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.

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