Drug interactions
Ferric maltol + Phenytoin
Severity: Moderate
Ferric maltol and Phenytoin: 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
Iron preparations may bind phenytoin in the gut or otherwise reduce its absorption, which can lower phenytoin levels and risk breakthrough seizures. Phenytoin may also affect iron absorption, though this is less clinically important.
What this interaction means in plain words
Ferric maltol and Phenytoin 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; Phenytoin belongs to Central Nervous System.
Why it happens
Reduced oral absorption of phenytoin, probably through complexation with iron in the gastrointestinal tract.
What to do
Separate ferric maltol and phenytoin doses by at least 2 hours. Monitor phenytoin levels and seizure control when 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 Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
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 Phenytoin?
MediHelp rates the interaction as moderate. Ferric maltol and Phenytoin 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. Iron preparations may bind phenytoin in the gut or otherwise reduce its absorption, which can lower phenytoin levels and risk breakthrough seizures. Phenytoin may also affect iron absorption, though this is less clinically important.
How serious is the interaction between Ferric maltol and Phenytoin?
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 ferric maltol and phenytoin doses by at least 2 hours. Monitor phenytoin levels and seizure control when starting or stopping iron.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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