Heparin and Indomethacin Interaction
Drug interaction information between Heparin and Indomethacin.
Heparin and Indomethacin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Heparin 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.
How They Interact
Both drugs make it harder for your blood to clot, which increases the risk of bleeding. Indomethacin stops platelets from sticking together, while heparin thins the blood.
What To Do
Use this combination with caution. Your doctor should watch closely for any signs of bleeding.
FDA Label Information
7.2 Platelet Inhibitors Drugs such as NSAIDS (including salicylic acid, ibuprofen, indomethacin, and celecoxib), dextran, phenylbutazone, thienopyridines, dipyridamole, hydroxychloroquine, glycoprotein IIb/IIIa antagonists (including abciximab, eptifibatide, and tirofiban), and others that interfere with platelet-aggregation reactions (the main hemostatic defense of heparinized patients) may induce bleeding and should be used with caution in patients receiving heparin sodium.
Heparin Also Interacts With
- Ibuprofen moderate
- Celecoxib moderate
- Hydroxychloroquine moderate
- Dipyridamole moderate
- Apixaban moderate
Indomethacin Also Interacts With
- Methotrexate moderate
- Diflunisal moderate
- Perindopril moderate
- Warfarin moderate
- Meloxicam minor
Frequently Asked Questions
Can I take Heparin and Indomethacin together?
This is a moderate interaction. Use this combination with caution. Your doctor should watch closely for any signs of bleeding.
How serious is the interaction between Heparin 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 Heparin and Indomethacin interact?
Both drugs make it harder for your blood to clot, which increases the risk of bleeding. Indomethacin stops platelets from sticking together, while heparin thins the blood.
Understanding the Heparin and Indomethacin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Heparin belongs to the Unfractionated Heparin 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: Both drugs make it harder for your blood to clot, which increases the risk of bleeding. 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. Heparin has 20 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: Use this combination with caution. 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 Heparin 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.
Read our methodology - how this data is sourced, computed, and verified.