Drug Interaction Report

Iron and Moxifloxacin Ophthalmic: Interaction Details

Name: Iron and Moxifloxacin Ophthalmic Interaction
Creator: Dr. Brian Staiger, PharmD, BCPS

A pharmacist-reviewed analysis of the Iron and Moxifloxacin Ophthalmic interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Moxifloxacin Ophthalmic

Moxeza® Vigamox Vigamox®

Iron

No brand names on record

Medically reviewed by

Dr. Brian Staiger, PharmD, BCPS

Updated Aug 8, 2026

Editorial policy · Data sources

Interaction severity

Moderate

Can be significant — usually manageable with monitoring.

Minor

Moderate

Major

Contraindicated

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.

Of 37 documented Iron interactions, 31 are rated moderate — including this one.

Onset

rapid

Evidence

probable

Severity

Moderate

What happens

Decreased moxifloxacin effectiveness

Interaction Deep Dive

A significant decrease in the bioavailability of moxifloxacin (approximately 50%) has been observed when coadministered with an iron formulation (Erifer(R))¹². When moxifloxacin was coadministered with ferrous sulfate (100 mg once daily for two days), the mean area under the concentration-time curve (AUC) and maximum concentration (Cmax) were decreased by 39% and 59%, respectively. Moxifloxacin should be administered at least four hours before or eight hours after iron ³.

Why it happens (mechanism)

Decreased moxifloxacin absorption due to chelation

Common questions

Can I take Iron and Moxifloxacin Ophthalmic together?

Decreased moxifloxacin effectiveness Always confirm with your pharmacist or prescriber before making any change.

How serious is the Iron and Moxifloxacin 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 Moxifloxacin 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 (3)

Anon: Moxifloxacin - close to ideal for respiratory infections. Scrip 1999; No. 2415:25.
Barman-Balfour JA & Wiseman LR: Moxifloxacin (review). Drugs 1999; 57:363-373.
Product Information: Avelox(TM), moxifloxacin hydrochloride. Bayer Corporation, West Haven, CT, 2003. DailyMed

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Moxifloxacin Ophthalmic

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All Moxifloxacin Ophthalmic interactions (282) Moxifloxacin Ophthalmic drug information

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A message from HelloPharmacist

About our interaction database: depth, not breadth

HelloPharmacist doesn't license one of the big commercial interaction databases, so what you'll find here is not a complete list of every known drug interaction. Instead, each entry is researched, analyzed, and written up individually — documented from the published literature, reviewed by a pharmacist, and cited so you can check every source yourself.

If a combination isn't listed here, it means we haven't documented it yet — never that it's safe. For screening a full medication list, we recommend pairing this site with a comprehensive tool like the Drugs.com Interaction Checker and, most importantly, a review by your own pharmacist. For a deep, plain-English, fully sourced explanation of a specific documented interaction — that's exactly what we built this for.

This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.