Iron and Gatifloxacin Ophthalmic: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Gatifloxacin Ophthalmic
Iron
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
Decreased gatifloxacin effectiveness
Interaction Deep Dive
When a single oral dose of gatifloxacin 400 mg was administered concurrently with a single oral dose of ferrous sulfate 325 mg, the maximum concentration of gatifloxacin was decreased by 54% while the area under the concentration-time curve was reduced by 35%. Administering gatifloxacin two hours before or two hours after ferrous sulfate did not significantly alter the oral bioavailability of gatifloxacin. It is recommended that gatifloxacin be administered at least four hours before iron or any product containing iron1.
Why it happens (mechanism)
Decreased gatifloxacin absorption due to chelation
Common questions
Can I take Iron and Gatifloxacin Ophthalmic together?
Decreased gatifloxacin effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Iron and Gatifloxacin 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 "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Iron or Gatifloxacin 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)
- Product Information: Tequin(TM), gatifloxacin. Bristol-Myers Squibb Company, Princeton, NJ, 1999. DailyMed
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