Deflazacort and Telithromycin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telithromycin
No brand names on recordDeflazacort
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 exposure to active metabolite of deflazacort
Interaction Deep Dive
Coadministration of deflazacort with strong and moderate CYP3A4 inhibitors may increase exposure to the active metabolite of deflazacort, 21-desDFZ, which is a CYP3A4 substrate. Deflazacort administered following multiple doses of clarithromycin (a strong CYP3A4 and P-gp inhibitor) increased geometric mean exposure to the deflazacort active metabolite, 21-desDFZ, by 2.3- to 3.4-fold compared with deflazacort alone. When coadministration is necessary, administer one-third the usual dosage of deflazacort; for example, a dose of 36 mg/day would be reduced to 12 mg/day1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of active metabolite of deflazacort
Literature reports
1 report — tap to read
a) Deflazacort administered following multiple doses of clarithromycin (a strong CYP3A4 and P-gp inhibitor) increased geometric mean exposure to the deflazacort active metabolite, 21-desDFZ, by 2.3- to 3.4-fold compared with deflazacort alone 1.
Common questions
Can I take Deflazacort and Telithromycin together?
Increased exposure to active metabolite of deflazacort Always confirm with your pharmacist or prescriber before making any change.
How serious is the Deflazacort and Telithromycin 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Deflazacort or Telithromycin 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: EMFLAZA(TM) oral tablets, suspension, deflazacort oral tablets, suspension. Marathon Pharmaceuticals LLC (per FDA), Northbrook, IL, 2017. DailyMed
Keep reading about Telithromycin
Keep reading about Deflazacort
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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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