Cobicistat and Mometasone Oral Inhalation: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cobicistat
Mometasone Oral Inhalation
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 mometasone exposure and an increased risk for systemic corticosteroid effects
Interaction Deep Dive
Coadministration of cobicistat (strong CYP3A inhibitor) with mometasone (corticosteroid), may result in a significant increase in mometasone exposure and can increase the risk for Cushing's syndrome and adrenal suppression. Consider alternative corticosteroids including beclomethasone, predniSONE, and prednisoLONE, whose pharmacokinetics and/or pharmacodynamics are less affected by strong CYP3A inhibitors, especially for long-term use1.
Why it happens (mechanism)
Inhibition of CYP3A-mediated metabolism of mometasone
Common questions
Can I take Cobicistat and Mometasone Oral Inhalation together?
Increased mometasone exposure and an increased risk for systemic corticosteroid effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cobicistat and Mometasone Oral Inhalation 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 Cobicistat or Mometasone Oral Inhalation 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: TYBOST(R) oral tablets, cobicistat oral tablets. Gilead Sciences Inc (per FDA), Foster City, CA, 2025. DailyMed
Keep reading about Cobicistat
Keep reading about Mometasone Oral Inhalation
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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