Warfarin and Cyclosporine Ophthalmic: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Warfarin
Cyclosporine 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 warfarin exposure, increased INR and reduced efficacy of cycloSPORINE and warfarin
Interaction Deep Dive
Concomitant use of warfarin (CYP3A4 substrate) with cycloSPORINE (CYP3A4 inhibitor) may increase warfarin exposure and may increase INR. The CYP3A4 inhibition potential should be considered when starting, stopping, or changing dose of concomitant medications. Closely monitor INR If a concomitant CYP3A4 inhibitor is used with warfarin1. There have been reports published that indicate a reduction in the anticoagulant activity of warfarin when cycloSPORINE are used concurrently 32.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated metabolism of warfarin; unknown
Literature reports
2 reports — tap to read
a) Concomitant administration of cycloSPORINE and warfarin was reported to result in significant reductions in cycloSPORINE serum concentrations and loss of therapeutic activity in a patient with pure erythrocyte aplasia. Increasing the dose of cycloSPORINE resulted in a decrease in the activity of warfarin, as evidenced by an increase in prothrombin activity, from 17% of control to 64%, necessitating increased doses of warfarin. This case report suggests that each drug interfered with the activity of the other. However, the patient was also taking PHENobarbital, which is capable of reducing the activity of both warfarin and cycloSPORINE, and it is unclear if a true interaction between the 2 agents exists. More studies are required to fully evaluate this interaction 2.
b) An interaction between cycloSPORINE and warfarin leading to a decrease in International Normalized Ratio (INR) has been reported. A 65-year-old female diagnosed with angioimmunoblastic T-cell lymphoma was given cycloSPORINE while receiving warfarin for venous thromboembolism. During six courses of standard CHOP regimen the patient developed a deep venous thrombosis (DVT) of her left leg. The DVT regressed when low molecular weight heparin was administered for 2 months. Long-term warfarin therapy was initiated after a CT scan of the abdomen demonstrated an asymptomatic vena cava thrombosis which spread from the iliac bifurcation to the renal veins. CycloSPORINE therapy was initiated after a lymphoma relapse to control the malignant T-cell proliferation. INR subsequently decreased about 40% after the beginning of cycloSPORINE therapy. A larger dose of warfarin had to be administered (from 18.75 to 27.5 mg/week). After the increase in warfarin dose, cycloSPORINE blood levels remained within the therapeutic range, and the INR values became stable with the same warfarin dose. When warfarin was discontinued, cycloSPORINE blood levels remained unchanged 3.
Common questions
Can I take Warfarin and Cyclosporine Ophthalmic together?
Increased warfarin exposure, increased INR and reduced efficacy of cycloSPORINE and warfarin Always confirm with your pharmacist or prescriber before making any change.
How serious is the Warfarin and Cyclosporine Ophthalmic interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
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 Warfarin or Cyclosporine 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 a safer alternative to one of these medications for me?
References (3)
- Product Information: WARFARIN SODIUM oral tablets, warfarin sodium oral tablets. Teva Pharmaceuticals (per Dailymed), Parsippany, NJ, 2023. DailyMed
- Snyder DS: Interaction between cyclosporine and warfarin (letter). Ann Intern Med 1988; 108:311. PubMed
- Turri D, Iannitto E, Caracciolo C, et al: Oral anticoagulants and cyclosporin A. Haematologica 2000; 85(8):893-894.
Keep reading about Warfarin
Keep reading about Cyclosporine 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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist