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Drug interactions

Diflunisal + Oxaprozin

Severity: Major

Diflunisal and Oxaprozin: major interaction.

Last updated Sources: US FDA label

For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.

Summary

Two NSAIDs given together raise the risk of gastrointestinal bleeding, renal impairment and fluid retention with no added efficacy.

What this interaction means in plain words

Diflunisal and Oxaprozin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Diflunisal belongs to Musculoskeletal; Oxaprozin belongs to Musculoskeletal.

Evidence level: High

Why it happens

Additive cyclooxygenase inhibition reducing gastric mucosal, platelet and renal prostaglandin functions.

What to do

Avoid concurrent NSAIDs and use a single agent at the lowest effective dose.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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References

Frequently asked questions

Can I take Diflunisal with Oxaprozin?

MediHelp rates the interaction as major. Diflunisal and Oxaprozin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Two NSAIDs given together raise the risk of gastrointestinal bleeding, renal impairment and fluid retention with no added efficacy.

How serious is the interaction between Diflunisal and Oxaprozin?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent NSAIDs and use a single agent at the lowest effective dose.

What other medicines interact with Diflunisal?

MediHelp also lists interactions of Diflunisal with, for example, Ketorolac, Ketorolac intranasal, Acemetacin. The full list is on the Diflunisal page.

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