Dexamethasone Injection and Fluconazole: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fluconazole
Dexamethasone Injection
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 dexAMETHasone exposure
Interaction Deep Dive
Coadministration of moderate CYP3A4 inhibitors like fluconazole increased dexAMETHasone exposure which may increase the risk of adverse reactions. Coadministration of aprepitant (a moderate CYP3A4 inhibitor) 125 mg on Day 1 and 80 mg once daily on Days 2 to 5 with oral dexAMETHasone (20 mg on Day 1, and 8 mg once daily on Day 2-5) increased dexAMETHasone AUC(inf) by 2.2 -fold on Day 1 and 51.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated dexAMETHasone metabolism by fluconazole
Literature reports
1 report — tap to read
a) Coadministration of aprepitant (a moderate CYP3A4 inhibitor) 125 mg on Day 1 and 80 mg once daily on Days 2 to 5 with oral dexAMETHasone (20 mg on Day 1, and 8 mg once daily on Day 2-5) increased dexAMETHasone AUC(inf) by 2.2 -fold on Day 1 and 5 1.
Common questions
Can I take Dexamethasone Injection and Fluconazole together?
Increased dexAMETHasone exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dexamethasone Injection and Fluconazole 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Dexamethasone Injection or Fluconazole 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: HEMADY(TM) oral tablets, dexamethasone oral tablets. Acrotech Biopharma LLC (per FDA), East Windsor, NJ, 2021. DailyMed
Keep reading about Fluconazole
Keep reading about Dexamethasone Injection
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.
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