Entacapone and Diclofenac Ophthalmic: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Entacapone
Diclofenac Ophthalmic
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
Increased diclofenac exposure
Interaction Deep Dive
Concomitant use of a CYP2C9 substrate, such as diclofenac and entacapone (a CYP2C9 inhibitor) should be undertaken with caution as this may increase1 diclofenac plasma concentrations and increase the risk of adverse effects. If coadministration is required, evaluate patient medical history before prescribing diclofenac 2 and adjust the carbidopa/levodopa/entacapone dose as clinically indicated 1.
Why it happens (mechanism)
Inhibition of CYP2C9-mediated diclofenac metabolism by entacapone
Common questions
Can I take Entacapone and Diclofenac Ophthalmic together?
Increased diclofenac exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Entacapone and Diclofenac Ophthalmic interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
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.
Questions for your pharmacist
- Does my dose of Entacapone or Diclofenac Ophthalmic 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 anything you'd monitor while I'm on both?
References (2)
- Product Information: STALEVO(R) oral tablets, carbidopa levodopa entacapone oral tablets. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2014.
- Product Information: ZORVOLEX(TM) oral capsules, diclofenac oral capsules. Iroko Pharmaceuticals, LLC (per manufacturer), Philadelphia, PA, 2013. DailyMed
Keep reading about Entacapone
Keep reading about Diclofenac Ophthalmic
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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