Ketoconazole Topical and Clobazam: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clobazam
Ketoconazole Topical
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased systemic exposure to clobazam
Interaction Deep Dive
Concurrent use of clobazam and ketoconazole may result in increased systemic exposure to clobazam, due to inhibition of CYP3A4-mediated clobazam metabolism. When clobazam and ketoconazole (a strong CYP3A4 inhibitor) were co-administered orally for 5 days, the AUC of clobazam increased by 54%1. Monitor for excessive benzodiazepine exposure and side effects when clobazam and ketoconazole are used concurrently.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated clobazam metabolism
Literature reports
1 report — tap to read
a) When clobazam was co-administered with ketoconazole 400 mg orally once daily for 5 days (n=18), clobazam AUC increased by 54%, with no significant effect on clobazam Cmax. There was no significant change in AUC and Cmax of N-desmethylclobazam, the active metabolite of clobazam 1.
Common questions
Can I take Ketoconazole Topical and Clobazam together?
Increased systemic exposure to clobazam Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ketoconazole Topical and Clobazam interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Ketoconazole Topical or Clobazam need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: ONFI(TM) oral tablets, clobazam oral tablets. Lundbeck Inc. (per manufacturer), Deerfield, IL, 2011. DailyMed
Keep reading about Clobazam
Keep reading about Ketoconazole Topical
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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