Does Ondansetron Interact With Rifampin?

In patients treated with potent inducers of CYP3A4 (i.e., phenytoin, carbamazepine, and rifampin), the clearance of ondansetron was significantly increased and ondansetron blood concentrations were decreased.

Severity: Minor

Severity basis: drug interactions section. Combining Ondansetron (5-HT3 antiemetic) and Rifampin (Rifamycin antibiotic (strong CYP3A4 inducer)) 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

In patients treated with potent inducers of CYP3A4 (i.e., phenytoin, carbamazepine, and rifampin), the clearance of ondansetron was significantly increased and ondansetron blood concentrations were decreased.

Source: FDA structured product labeling (set_id 00327696-c496-4c83-a63e-9e29fd6246d4).

Ondansetron

5-HT3 antiemetic

Brands: Zofran

View Ondansetron safety profile

Rifampin

Rifamycin antibiotic (strong CYP3A4 inducer)

Brands: Rifadin

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 It may be incomplete or out of date, and individual circumstances vary.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