Glasdegib and Lorlatinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lorlatinib
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
Reduced glasdegib exposure
Interaction Deep Dive
Concomitant use of glasdegib and a moderate CYP3A4 inducer may decrease glasdegib exposure and should be avoided. If use cannot be avoided, increase the glasdegib dosage as tolerated: If current glasdegib dosage is 100 mg/day, increase to 200 mg/day; if current glasdegib dosage is 50 mg/day, increase to 100 mg/day. After the moderate CYP3A4 inducer has been discontinued for 7 days, resume the glasdegib dose taken prior to initiating the moderate CYP3A4 inducer1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of glasdegib
Literature reports
1 report — tap to read
a) Coadministration of glasdegib and efavirenz (moderate CYP3A4 inducer) is predicted to decrease glasdegib AUC(0 to infinity) by 55% and Cmax by 25% 1.
Common questions
Can I take Glasdegib and Lorlatinib together?
Reduced glasdegib exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Glasdegib and Lorlatinib 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 Glasdegib or Lorlatinib 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, 2020. DailyMed
Keep reading about Lorlatinib
Keep reading about Glasdegib
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