Oxaprozin and Methotrexate Interaction
Drug interaction information between Oxaprozin and Methotrexate.
Oxaprozin and Methotrexate have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Oxaprozin and Methotrexate. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Oxaprozin can cause methotrexate to build up in your blood to dangerous levels by making it harder for your body to clear the drug. This increases the risk of serious side effects like low blood cell counts or kidney problems.
What To Do
Your doctor should monitor you closely for signs of methotrexate toxicity while you are taking both medications.
FDA Label Information
Methotrexate Clinical Impact: Concomitant use of NSAIDs and methotrexate may increase the risk for methotrexate toxicity (e.g., neutropenia, thrombocytopenia, renal dysfunction) because NSAID administration may result in increased plasma levels of methotrexate, especially in patients receiving high doses of methotrexate. Intervention: During concomitant use of COXANTO and methotrexate, monitor patients for methotrexate toxicity.
Oxaprozin Also Interacts With
- Furosemide moderate
- Diflunisal moderate
- Warfarin moderate
- Meloxicam minor
- Aspirin minor
Methotrexate Also Interacts With
- Celecoxib moderate
- Diflunisal moderate
- Indomethacin moderate
- Mefenamic Acid moderate
- Meloxicam moderate
Frequently Asked Questions
Can I take Oxaprozin and Methotrexate together?
This is a moderate interaction. Your doctor should monitor you closely for signs of methotrexate toxicity while you are taking both medications.
How serious is the interaction between Oxaprozin and Methotrexate?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Oxaprozin and Methotrexate interact?
Oxaprozin can cause methotrexate to build up in your blood to dangerous levels by making it harder for your body to clear the drug. This increases the risk of serious side effects like low blood cell counts or kidney problems.
Understanding the Oxaprozin and Methotrexate Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Oxaprozin belongs to the Nonsteroidal Anti-Inflammatory Drug (NSAID) class and Methotrexate belongs to the Disease-Modifying Antirheumatic Drug (DMARD) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Oxaprozin can cause methotrexate to build up in your blood to dangerous levels by making it harder for your body to clear the drug. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Oxaprozin has 15 total documented interactions on file in this dataset, and Methotrexate has 38. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor you closely for signs of methotrexate toxicity while you are taking both medications. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Oxaprozin or Methotrexate based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.