Ketoconazole Topical and Darunavir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Darunavir
No brand names on recordKetoconazole 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 ketoconazole exposure and an increased darunavir exposure
Interaction Deep Dive
Exert caution when strong CYP3A4 inhibitors (e.g. antivirals such as ritonavir-boosted darunavir) coadministered with oral ketoconazole1. Coadministration of darunavir/ritonavir and ketoconazole may increase both darunavir and ketoconazole exposure. When coadministration of darunavir/ritonavir and ketoconazole is necessary, the daily dose of ketoconazole should not exceed 200 mg per day. Monitor patients for increased adverse effects of darunavir and ketoconazole 2.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of ketoconazole; inhibition of CYP3A4-mediated metabolism of darunavir
Literature reports
1 report — tap to read
a) In a pharmacokinetics study, concurrent administration of ketoconazole and darunavir/ritonavir significantly increased plasma concentrations of both darunavir and ketoconazole. Subjects (n=15) were administered ketoconazole 200 mg orally twice daily concurrently with darunavir 400 mg/ritonavir 100 mg orally twice daily. This led to significant increases in ketoconazole AUC, Cmax, and Cmin by 212% (least squares (LS) mean ratio % 3.12; 90% confidence interval (CI), 2.65 to 3.68), 111% (LS mean ratio % 2.11; 90% CI, 1.81 to 2.44), and 868% (LS mean ratio % 9.68; 90% CI, 6.44 to 14.55), respectively. Darunavir AUC, Cmax, and Cmin were also increased by 42% (LS mean ratio % 1.42, 90% CI, 1.23 to 1.65), 21% (LS mean ratio % 1.21, 90% CI, 1.04 to 1.4), and 73% (LS mean ratio % 1.73, 90% CI, 1.39 to 2.14) respectively 2.
Common questions
Can I take Ketoconazole Topical and Darunavir together?
Increased ketoconazole exposure and an increased darunavir exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ketoconazole Topical and Darunavir interaction?
It is rated major. Potentially serious — often needs a change or close 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Ketoconazole Topical or Darunavir 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 a safer alternative to one of these medications for me?
References (2)
- Product Information: Ketoconazole oral tablet, ketoconazole oral tablet. Taro Pharmaceuticals U.S.A. Inc. (per DailyMed), Hawthorne, NY, 2024. DailyMed
- Product Information: PREZISTA(R) oral suspension, oral tablets, darunavir oral suspension, oral tablets. Janssen Products, LP (per FDA), Horsham, PA, 2023. DailyMed
Keep reading about Darunavir
Keep reading about Ketoconazole Topical
These medications also interact with supplements
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist