Drug interactions
Ferrous sulfate + Oxytetracycline
Severity: Moderate
Ferrous sulfate and Oxytetracycline: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Oral iron binds oxytetracycline in the gut to form poorly absorbed chelates. This can substantially lower antibiotic levels and cause treatment failure.
What this interaction means in plain words
Ferrous sulfate and Oxytetracycline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Ferrous sulfate belongs to Miscellaneous; Oxytetracycline belongs to Anti Bacterial.
Why it happens
Chelation of tetracycline by iron cations in the gastrointestinal tract, reducing absorption.
What to do
Give oxytetracycline at least 2 hours before or 3 hours after the iron preparation, or temporarily pause iron during a short antibiotic course.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Ferrous sulfate and Oxytetracycline, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Ferrous sulfate
Other interactions of Oxytetracycline
- Isotretinoin + Oxytetracycline Contraindicated
- Aluminum hydroxide + Oxytetracycline Moderate
- Ampicillin-sulbactam + Oxytetracycline Moderate
- Ampicillin + Oxytetracycline Moderate
- Atracurium + Oxytetracycline Moderate
- Bismuth subsalicylate + Oxytetracycline Moderate
Frequently asked questions
Can I take Ferrous sulfate with Oxytetracycline?
MediHelp rates the interaction as moderate. Ferrous sulfate and Oxytetracycline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Oral iron binds oxytetracycline in the gut to form poorly absorbed chelates. This can substantially lower antibiotic levels and cause treatment failure.
How serious is the interaction between Ferrous sulfate and Oxytetracycline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Give oxytetracycline at least 2 hours before or 3 hours after the iron preparation, or temporarily pause iron during a short antibiotic course.
What other medicines interact with Ferrous sulfate?
MediHelp also lists interactions of Ferrous sulfate with, for example, Ciprofloxacin, Dimercaprol, Acetohydroxamic acid. The full list is on the Ferrous sulfate page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
