Methotrexate Injection and Etoricoxib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Methotrexate Injection
Etoricoxib
No brand names on record
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 methotrexate plasma concentrations and toxicity
Interaction Deep Dive
Effects of etoricoxib, a COX-2 inhibitor, on methotrexate plasma concentrations and renal clearance were mixed in clinical studies, with one trial showing increased methotrexate blood concentrations and decreased renal clearance with high daily doses (120 mg) of etoricoxib, while another trial showed no effects on methotrexate blood levels or renal clearance with any (60, 90, or 120 mg) etoricoxib dose. Monitor methotrexate plasma concentrations and for methotrexate toxicity during therapy if etoricoxib and methotrexate coadministration is necessary1.
Why it happens (mechanism)
Decrease in renal excretion by etoricoxib
Literature reports
1 report — tap to read
a) In one clinical trial, a 28% increase in methotrexate plasma concentrations and a 13% decrease in methotrexate renal clearance occurred with 7-day administration of etoricoxib 120 mg/day combined with one dose of methotrexate 7.5 to 20 mg for rheumatoid arthritis. No effects on methotrexate plasma concentrations or renal clearance were seen with etoricoxib 60 or 90 mg/day coadministration. Another study with identical etoricoxib and methotrexate dosing parameters showed no effects on methotrexate plasma concentrations nor renal clearance with etoricoxib administration 1.
Common questions
Can I take Methotrexate Injection and Etoricoxib together?
Increased methotrexate plasma concentrations and toxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Methotrexate Injection and Etoricoxib interaction?
It is rated moderate. Can be significant — usually manageable with 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Methotrexate Injection or Etoricoxib 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 anything you'd monitor while I'm on both?
References (1)
- eMC: Arcoxia 30mg, 60mg, 90mg & 120mg film-coated tablets, SPC dated November 2012. Datapharm Communications Ltd. Surrey, United Kingdom. 2013.
Keep reading about Methotrexate Injection
Keep reading about Etoricoxib
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