Drug Interaction Report

Ibrexafungerp and Posaconazole: Interaction Details

A pharmacist-reviewed analysis of the Ibrexafungerp and Posaconazole interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Posaconazole

Noxafil
+

Ibrexafungerp

Brexafemme Brexafemme®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 111 documented Ibrexafungerp interactions, 99 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Increased ibrexafungerp exposure and an increased posaconazole exposure

Interaction Deep Dive

Concomitant use of ibrexafungerp and posaconazole (strong CYP3A inhibitor) has significantly increased ibrexafungerp exposure. If coadministered, reduce ibrexafungerp dosage to 150 mg approximately 12 hours apart (eg, in the morning and in the evening) for one day1. Concomitant use of posaconazole with ibrexafungerp (P-gp inhibitor) may increase posaconazole exposure 23.

Why it happens (mechanism)

Inhibition of CYP3A-mediated metabolism of ibrexafungerp; inhibition of P-gp-mediated efflux transport of posaconazole

Literature reports

1 report — tap to read

a) Coadministration of ketoconazole 400 mg once daily for 15 days (strong CYP3A4 and P-gp inhibitor) with ibrexafungerp, increased the ibrexafungerp AUC by 5.8-fold and Cmax by 2.5-fold 1.

Common questions

Can I take Ibrexafungerp and Posaconazole together?

Increased ibrexafungerp exposure and an increased posaconazole exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Ibrexafungerp and Posaconazole 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 Ibrexafungerp or Posaconazole 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 (3)

  1. Product Information: Brexafemme(R) oral tablets, ibrexafungerp oral tablets. Scynexis, Inc. (per manufacturer), Jersey City, NJ, 2021.
  2. Product Information: NOXAFIL(R) PowderMix delayed-release oral suspension, posaconazole delayed-release oral suspension. Merck Sharp & Dohme LLC (per FDA), Rahway, NJ, 2024. DailyMed
  3. Product Information: Posaconazole oral delayed-release tablets, posaconazole oral delayed-release tablets. SpecGx LLC (per DailyMed), Webster Groves, MO, 2024. DailyMed
Was this write-up helpful?
Posaconazole

Keep reading about Posaconazole

All Posaconazole interactions (166)
Also serious with: Entrectinib Encorafenib Alfuzosin Fluvastatin
Ibrexafungerp

Keep reading about Ibrexafungerp

All Ibrexafungerp interactions (111) Ibrexafungerp drug information
Also serious with: Colchicine Ensitrelvir Levoketoconazole Finerenone
Beyond drug–drug

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:

Posaconazole + Activated Charcoal Coffee Charcoal European Mandrake Glucomannan Guar Gum Gum Arabic Slippery Elm Tragacanth + 9 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.