Aspirin and Ketorolac: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Aspirin
Ketorolac
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
Enhanced gastrointestinal adverse effects (peptic ulcers, gastrointestinal bleeding, and/or perforation) and possible increase in serum ketorolac levels
Interaction Deep Dive
Oral ketorolac is contraindicated in patients currently receiving aspirin or NSAIDs because of the cumulative risks of inducing serious NSAID-related adverse events (peptic ulcers, gastrointestinal bleeding, and/or perforation). In addition, free ketorolac plasma levels may increase during concomitant administration with salicylates. At therapeutic concentrations of salicylate (300 mcg/mL), the binding of ketorolac was reduced from approximately 99.2% to 97.5%, representing a potential 2-fold increase in unbound ketorolac plasma levels2. The concomitant use of ketorolac nasal spray and aspirin is also generally not recommended 1.
Why it happens (mechanism)
Additive gastrointestinal irritation and reduced ketorolac plasma protein binding
Common questions
Can I take Aspirin and Ketorolac together?
Enhanced gastrointestinal adverse effects (peptic ulcers, gastrointestinal bleeding, and/or perforation) and possible increase in serum ketorolac levels Always confirm with your pharmacist or prescriber before making any change.
How serious is the Aspirin and Ketorolac interaction?
It is rated contraindicated. These should generally not be used together.
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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Aspirin or Ketorolac 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 a safer alternative to one of these medications for me?
References (2)
Keep reading about Aspirin
Keep reading about Ketorolac
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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