Drug interactions
Ferric maltol + Levothyroxine
Severity: Moderate
Ferric maltol and Levothyroxine: 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 products bind levothyroxine in the gut and reduce its absorption, which can raise TSH and lead to hypothyroid symptoms. Ferric maltol is expected to behave similarly to other oral iron preparations.
What this interaction means in plain words
Ferric maltol and Levothyroxine 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.
Ferric maltol belongs to Miscellaneous; Levothyroxine belongs to Endocrine.
Why it happens
Iron forms insoluble chelates with levothyroxine in the gastrointestinal tract, reducing absorption.
What to do
Separate levothyroxine and ferric maltol by at least 4 hours. Check TSH 6 to 8 weeks after starting or stopping iron.
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?
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Other interactions of Levothyroxine
Other interactions of Ferric maltol
- Aluminum hydroxide + Ferric maltol Moderate
- Calcium carbonate + Ferric maltol Moderate
- Calcium + Ferric maltol Moderate
- Carbidopa-entacapone-levodopa + Ferric maltol Moderate
- Carbidopa-levodopa + Ferric maltol Moderate
- Cimetidine + Ferric maltol Moderate
Frequently asked questions
Can I take Ferric maltol with Levothyroxine?
MediHelp rates the interaction as moderate. Ferric maltol and Levothyroxine 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 products bind levothyroxine in the gut and reduce its absorption, which can raise TSH and lead to hypothyroid symptoms. Ferric maltol is expected to behave similarly to other oral iron preparations.
How serious is the interaction between Ferric maltol and Levothyroxine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Separate levothyroxine and ferric maltol by at least 4 hours. Check TSH 6 to 8 weeks after starting or stopping iron.
What other medicines interact with Levothyroxine?
MediHelp also lists interactions of Levothyroxine with, for example, Cholestyramine, Sodium iodide i-131, Tiratricol. The full list is on the Levothyroxine page.
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