Does Ketoconazole Interact With Rifampin?

Telaprevir Decrease AUC by 92% Systemic Hormonal Contraceptives Prevention or Management: Advise patients to change to non-hormonal methods of birth control during rifampin therapy Estrogens Decrease exposure Progestins Anticonvulsants Phenytoin Administered with rifampin 450 mg daily Decrease exposure Antiarrhythmics Disopyramide Decrease exposure Mexiletine Decrease exposure Quinidine Decrease exposure Propafenone Decrease AUC by 50%–67% Tocainide Decrease exposure Antiestrogens Tamoxifen D…

Severity: Major

Severity basis: drug interactions section (keywords: contraindicated, avoid, not recommended). Combining Ketoconazole (Azole antifungal (strong CYP3A4 inhibitor)) and Rifampin (Rifamycin antibiotic (strong CYP3A4 inducer)) is classified as a major interaction.

What to Do

The label advises avoiding this combination or using it only under close medical supervision. Talk to your prescriber or pharmacist before combining them.

From the FDA Label

Telaprevir Decrease AUC by 92% Systemic Hormonal Contraceptives Prevention or Management: Advise patients to change to non-hormonal methods of birth control during rifampin therapy Estrogens Decrease exposure Progestins Anticonvulsants Phenytoin Administered with rifampin 450 mg daily Decrease exposure Antiarrhythmics Disopyramide Decrease exposure Mexiletine Decrease exposure Quinidine Decrease exposure Propafenone Decrease AUC by 50%–67% Tocainide Decrease exposure Antiestrogens Tamoxifen D…

Source: FDA structured product labeling (set_id 036ab68e-5085-4edc-bd83-784b43d64eab).

Ketoconazole

Azole antifungal (strong CYP3A4 inhibitor)

Brands: Nizoral

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 It may be incomplete or out of date, and individual circumstances vary.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