Quercetin and Cyclosporine Ophthalmic: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cyclosporine Ophthalmic
Quercetin
No brand names on record
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
Reduced cycloSPORINE effectiveness
Interaction Deep Dive
Quercetin significantly reduced the bioavailability of cycloSPORINE in rats and pigs. This study conflicts with in vitro studies demonstrating that quercetin inhibited cytochrome P450 3A4 and p-glycoprotein, which would suggest that quercetin should increase cycloSPORINE bioavailability1. It is unknown if the same effect will occur in humans. Caution is advised if quercetin is taken with cycloSPORINE.
Why it happens (mechanism)
Unknown
Literature reports
1 report — tap to read
a) Quercetin significantly reduced the bioavailability of cycloSPORINE in rats and pigs. Animals received a single dose of cycloSPORINE 10 milligrams/kilogram (mg/kg) with and without quercetin 50 mg/kg in crossover design. In pigs, the area-under-the-curve (AUC) (zero to 3 hours) was reduced by 56% (p less than 0.05), though the reduction in AUC from zero to 24 hours was not statistically significant. In rats, the AUC (zero to 36 hours) was reduced by 43% (p less than 0.05). Quercetin inhibited the p-glycoprotein-mediated efflux transport of rhodamine ex vivo 1.
Common questions
Can I take Quercetin and Cyclosporine Ophthalmic together?
Reduced cycloSPORINE effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Quercetin and Cyclosporine Ophthalmic interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
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 Quercetin 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 anything you'd monitor while I'm on both?
References (1)
- Hsiu SL, Hou YC, Wang YH, et al: Quercetin significantly decreased cyclosporin oral bioavailability in pigs and rats. Life Sci 2002; 72:227-235. PubMed
Keep reading about Cyclosporine Ophthalmic
Keep reading about Quercetin
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