Drug interactions
Ferrous fumarate + Sodium sulfate / ?magnesium sulfate / potassium chloride
Severity: Minor
Ferrous fumarate and Sodium sulfate / ?magnesium sulfate / potassium chloride: minor 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
Taking oral iron around a sulfate-based bowel preparation can reduce iron absorption. The laxative effect shortens gut transit and magnesium may bind iron. The result is usually a transient loss of iron uptake around the colonoscopy preparation.
What this interaction means in plain words
Ferrous fumarate and Sodium sulfate / ?magnesium sulfate / potassium chloride have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Magnesium chelation and rapid intestinal transit from the osmotic purgative reduce iron absorption.
What to do
Take oral iron at least 2 hours before or 6 hours after each bowel preparation dose. Iron is often withheld in the days before colonoscopy anyway.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Ferrous fumarate
Frequently asked questions
Can I take Ferrous fumarate with Sodium sulfate / ?magnesium sulfate / potassium chloride?
MediHelp rates the interaction as minor. Ferrous fumarate and Sodium sulfate / ?magnesium sulfate / potassium chloride have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Taking oral iron around a sulfate-based bowel preparation can reduce iron absorption. The laxative effect shortens gut transit and magnesium may bind iron. The result is usually a transient loss of iron uptake around the colonoscopy preparation.
How serious is the interaction between Ferrous fumarate and Sodium sulfate / ?magnesium sulfate / potassium chloride?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Take oral iron at least 2 hours before or 6 hours after each bowel preparation dose. Iron is often withheld in the days before colonoscopy anyway.
What other medicines interact with Ferrous fumarate?
MediHelp also lists interactions of Ferrous fumarate with, for example, Ciprofloxacin, Acetohydroxamic acid, Aluminum hydroxide. The full list is on the Ferrous fumarate page.
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