Glasdegib and Clarithromycin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Clarithromycin
Glasdegib
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 glasdegib concentration and increased risk of QTc interval prolongation
Interaction Deep Dive
Concomitant use of glasdegib (CYP3A4 substrate) and a strong CYP3A4 inhibitor that also prolongs the QTc interval increases the plasma concentrations of glasdegib and the risk of QTc interval prolongation. Consider alternative therapies that are not strong CYP3A4 inhibitors during treatment with glasdegib. Monitor patients for increased risk of adverse reactions including QTc interval prolongation if coadministered1.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated glasdegib metabolism and additive effects on the QTc interval
Literature reports
1 report — tap to read
a) Coadministration of ketoconazole (a strong inhibitor of CYP3A4) with glasdegib increased the glasdegib AUC(infinity) by 2.4-fold and Cmax by 1.4-fold compared with glasdegib given alone 1.
Common questions
Can I take Glasdegib and Clarithromycin together?
Increased glasdegib concentration and increased risk of QTc interval prolongation Always confirm with your pharmacist or prescriber before making any change.
How serious is the Glasdegib and Clarithromycin 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Glasdegib or Clarithromycin 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: DAURISMO(TM) oral tablets, glasdegib oral tablets. Pfizer Labs (per FDA), New York, NY, 2018. DailyMed
Keep reading about Clarithromycin
Keep reading about Glasdegib
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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