Elbasvir and Ketoconazole Topical: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Ketoconazole Topical
Elbasvir
No brand names on record
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 elbasvir exposure and an increase elbasvir-related adverse reactions
Interaction Deep Dive
Concomitant use of elbasvir/grazoprevir and oral ketoconazole is not recommended, as it may increase elbasvir exposure and may also increase elbasvir-related adverse reactions. When a single dose of elbasvir 50 mg was coadministered in patients receiving oral ketoconazole 400 mg once daily (N=7), the elbasvir AUC, Cmax and Cmin increased by 1.8-fold 1.29-fold and 1.89-fold, respectively1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of elbasvir
Literature reports
1 report — tap to read
a) When a single dose of elbasvir 50 mg was coadministered in patients receiving oral ketoconazole 400 mg once daily (N=7), the elbasvir AUC, Cmax and Cmin increased by 1.8-fold 1.29-fold and 1.89-fold, respectively 1.
Common questions
Can I take Elbasvir and Ketoconazole Topical together?
Increased elbasvir exposure and an increase elbasvir-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Elbasvir and Ketoconazole Topical 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 Elbasvir or Ketoconazole Topical 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 (1)
- Product Information: ZEPATIER(R) oral tablets, elbasvir grazoprevir oral tablets. Merck Sharp & Dohme Corp (per FDA), Whitehouse Station, NJ, 2021. DailyMed
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