The short answer
Iron preparations can reduce absorption of oral levofloxacin. Take the tablet at least 2 hours before or 2 hours after oral iron, following the current product label. Iron contained in a multivitamin also needs to be included when arranging the schedule.
What this answer covers
Oral levofloxacin tablets with oral iron products. The directly inspected trial tested ferrous sulfate; injected iron and other antibiotic routes are not assessed by this absorption evidence.
- Supplement or preparation
- Iron
- Medication ingredient
- levofloxacin
How much can iron change absorption?
An early human crossover study used ferrous sulfate 160 mg with a 100 mg levofloxacin preparation. Relative antibiotic bioavailability was 81% of the control value. That result supports an absorption concern but is not a universal 19% reduction for every iron dose, salt, or antibiotic formulation. The study did not compare infection cure rates.
What timing does the label recommend?
Keep at least 2 hours between levofloxacin tablets and the iron product, whether iron is taken first or second. Current labeling and patient guidance agree on that schedule. If your prescriber has supplied different instructions for a particular treatment plan, have the pharmacist reconcile them with the exact medicines rather than guessing which instruction applies.
What if iron is part of another supplement?
Check prenatal vitamins and other combined supplements for iron on their ingredient panels. A product does not have to be marketed primarily as iron to contain an interacting amount. The retrieved sources do not establish a universal amount below which timing can be ignored, and the measured ferrous-sulfate effect does not prove that every iron complex behaves identically.
Should I stop treatment for iron deficiency?
A scheduling interaction does not by itself mean that prescribed iron is unnecessary. Ask for a schedule that maintains the intended treatment for both conditions. Do not double the antibiotic to compensate for a past overlap. Keep the iron form and dose available when seeking advice, especially if several vitamin or mineral products are being used.
Evidence and practical considerations
Absorption & effectiveness
Iron preparations can reduce absorption of oral levofloxacin. Take the tablet at least 2 hours before or 2 hours after oral iron, following the current product label. Iron contained in a multivitamin also needs to be included when arranging the schedule.
- Exact scope
- oral iron preparations, with direct trial evidence for ferrous sulfate with oral levofloxacin hemihydrate tablets with strengths expressed as levofloxacin
- Medication form and route
- oral
- Timing or duration
- Concurrent single-dose exposure studied; spacing is relevant during each day of oral co-use.
What remains uncertain
- Effect size from a 100 mg antibiotic study and one iron salt cannot quantify every present-day product or infection outcome.
Factors that may matter: exact salt and dose; order and interval between doses; other mineral ingredients; oral tablet versus other routes.
Read the supporting source summaries
Source 1: regulatory product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral levofloxacin tablets.
Directs a minimum 2-hour gap before or after magnesium/aluminum antacids, iron and zinc-containing vitamin/mineral products. Calcium is not specifically named in this chelation instruction. Tablets may be taken with or without food.
How this applies: The label defines the pure (-)-(S) ofloxacin enantiomer hemihydrate as levofloxacin. This supports the exact oral formulation under parent RxCUI 82122; racemic ofloxacin, IV use and eye drops are not substituted. Article-specific counterparty: oral iron preparations, with direct trial evidence for ferrous sulfate.
Does not quantify each mineral salt or combination product; a listed interaction does not establish the magnitude of clinical treatment failure.
Source 2: human pharmacokinetic study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Healthy male volunteers in three randomized crossover studies; subgroup sizes were not given in the inspected abstract.
Relative antibiotic bioavailability was 56% with aluminum hydroxide, 78% with magnesium oxide, and 81% with ferrous sulfate. Calcium carbonate did not influence bioavailability under the tested regimen.
How this applies: DR-3355 is defined in the original abstract by the same pure (-)-(S) enantiomer hemihydrate chemical structure specified in current levofloxacin labeling, not racemic ofloxacin. Direct for the named salts with that oral preparation. Article-specific counterparty: oral iron preparations, with direct trial evidence for ferrous sulfate.
Small early pharmacokinetic studies used a 100 mg dose rather than current usual tablet strengths. No infection outcomes. Results differ by mineral and cannot be treated as one class effect. Full clinical paper was not assessed; inspected source is the original author abstract.
Source 3: institutional patient medication guidance
medlineplus.gov · Source check Sep 10, 2026
Population: People using oral levofloxacin tablets or solution.
Advises at least 2 hours of separation in either direction for the named products. Distinguishes tablet food instructions from the oral solution and advises discussing exact medicines and supplements.
How this applies: Supports practical scheduling for named oral products; the article remains restricted to tablets where product-label evidence is used. Article-specific counterparty: oral iron preparations, with direct trial evidence for ferrous sulfate.
Patient guidance is not a separate clinical experiment. No quantified individual zinc salt or multivitamin effect; calcium is not specifically included in this sentence.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Original product guidance and clinical studies checked; complete private article drafted with exact preparation limits and claim dispositions. | |
| Research summary published |
Article revision: 31865112ddd9eec7
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.