PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Diflunisal and Indomethacin Interaction

Drug interaction information between Diflunisal and Indomethacin.

Diflunisal and Indomethacin have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Diflunisal and Indomethacin. 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.

Drug A

Diflunisal

Nonsteroidal Anti-Inflammatory Drug (NSAID)

Drug B

Indomethacin

Nonsteroidal Anti-Inflammatory Drug (NSAID)

How They Interact

Diflunisal causes the body to have much higher levels of indomethacin in the blood. This increases the risk of serious stomach bleeding without making the medicine work any better.

What To Do

Avoid taking these two medicines together. This combination is dangerous and has been linked to fatal bleeding in the stomach.

FDA Label Information

NSAIDs and Salicylates Clinical Impact: Concomitant use of indomethacin with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy [ see Warnings and Precautions ( 5.2 ) ] . Combined use with diflunisal may be particularly hazardous because diflunisal causes significantly higher plasma levels of indomethacin [ see Clinical Pharmacology ( 12.3 ) ]. In some patients, combined use of indomethacin and diflunisal has been associated with fatal gastrointestinal hemorrhage.

Diflunisal Also Interacts With

View all Diflunisal interactions →

Indomethacin Also Interacts With

View all Indomethacin interactions →

Frequently Asked Questions

Can I take Diflunisal and Indomethacin together?

This is a moderate interaction. Avoid taking these two medicines together. This combination is dangerous and has been linked to fatal bleeding in the stomach.

How serious is the interaction between Diflunisal and Indomethacin?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Diflunisal and Indomethacin interact?

Diflunisal causes the body to have much higher levels of indomethacin in the blood. This increases the risk of serious stomach bleeding without making the medicine work any better.

Understanding the Diflunisal and Indomethacin Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Diflunisal belongs to the Nonsteroidal Anti-Inflammatory Drug (NSAID) class and Indomethacin belongs to the Nonsteroidal Anti-Inflammatory Drug (NSAID) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Diflunisal causes the body to have much higher levels of indomethacin in the blood. 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. Diflunisal has 17 total documented interactions on file in this dataset, and Indomethacin has 35. 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: Avoid taking these two medicines together. 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 Diflunisal or Indomethacin 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.