Dexamethasone Ophthalmic and Paclitaxel: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Dexamethasone Ophthalmic
Paclitaxel
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 PACLitaxel exposure
Interaction Deep Dive
Exercise caution when administering PACLitaxel concomitantly with CYP3A4 inducers as it may decrease PACLitaxel exposure. PACLitaxel is a CYP3A4 substrate with a narrow therapeutic index (NTI)12. In vitro studies, PACLitaxel was found to be metabolized primarily to 2 minor metabolites, 3'-p-hydroxyPACLitaxel and 6-alpha, 3'-p-dihydroxyPACLitaxel, by CYP3A4. The pharmacokinetics of PACLitaxel may be altered as a result of interactions in vivo with compounds that are inducers of CYP3A4 12.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of PACLitaxel
Literature reports
2 reports — tap to read
a) There are several case reports of decreased drug concentration and/or effectiveness have been reported when St. John's Wort was given with CYP3A4 substrates 345.
b) In vitro studies, PACLitaxel was found to be metabolized primarily to 2 minor metabolites, 3'-p-hydroxyPACLitaxel and 6-alpha, 3'-p-dihydroxyPACLitaxel, by CYP3A4. The pharmacokinetics of PACLitaxel may be altered as a result of interactions in vivo with compounds that are inducers of CYP3A4 12.
Common questions
Can I take Dexamethasone Ophthalmic and Paclitaxel together?
Reduced PACLitaxel exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dexamethasone Ophthalmic and Paclitaxel interaction?
It is rated major. Potentially serious — often needs a change or close 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 Dexamethasone Ophthalmic or Paclitaxel 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 (5)
- Product Information: PACLITAXEL intravenous injection, paclitaxel intravenous injection. Fresenius Kabi (per Dailymed), Lake Zurich, IL, 2024. DailyMed
- Product Information: PACLITAXEL PROTEIN-BOUND PARTICLES (ALBUMIN-BOUND) intravenous injection lyophilized powder for suspension, paclitaxel protein-bound particles (albumin-bound) intravenous injection lyophilized powder for suspension. Sandoz Inc (per Dailymed), Princeton, NJ, 2024. DailyMed
- Bolley R, Zulke C, Kammerl M, et al: Tacrolimus-induced nephrotoxicity unmasked by induction of the CYP3A4 system with St. John's Wort. Transplantation 2002; 73(6):1009. PubMed
- Piscitelli S, Burstein A, Chaitt D, et al: Indinavir concentrations and St. John's Wort. Lancet 2000; 355:547-548. DOI
- Ruschitzka F, Meier P, Turina M, et al: Acute heart transplant rejection due to St. John's Wort. Lancet 2000; 355:548-549.
Keep reading about Dexamethasone Ophthalmic
Keep reading about Paclitaxel
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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