Methotrexate and Momelotinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Methotrexate
Momelotinib
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 BCRP substrate exposure and an increased risk of BCRP substrate-related adverse reactions
Interaction Deep Dive
Concomitant administration of momelotinib (a BCRP inhibitor) with BCRP substrates may increase the exposure of BCRP substrates and may increase the risk of adverse reactions associated with BCRP substrates. When administered concomitantly, consider adjusting the dose of BCRP substrates1.
Why it happens (mechanism)
Inhibition of BCRP-mediated efflux transport by momelotinib
Literature reports
1 report — tap to read
a) In clinical studies, rosuvastatin (a BCRP substrate) Cmax increased by 220% and AUC increased by 170% following concomitant use of a single dose of rosuvastatin at 10 mg with multiple doses of momelotinib (200 mg once daily) 1.
Common questions
Can I take Methotrexate and Momelotinib together?
Increased BCRP substrate exposure and an increased risk of BCRP substrate-related adverse reactions Always confirm with your pharmacist or prescriber before making any change.
How serious is the Methotrexate and Momelotinib 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 Methotrexate or Momelotinib 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: OJJAARA oral tablets, momelotinib oral route. GlaxoSmithKline (per FDA), Durham, NC, 2023. DailyMed
Keep reading about Methotrexate
Keep reading about Momelotinib
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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