Drug interactions
Fleroxacin + Phenytoin
Severity: Moderate
Fleroxacin 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
Fluoroquinolones have been associated with changes in phenytoin levels, with both reduced and increased concentrations reported. This may lead to loss of seizure control or toxicity. Quinolones may also lower the seizure threshold.
What this interaction means in plain words
Fleroxacin 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.
Why it happens
The mechanism is not established.
What to do
Monitor serum phenytoin concentrations and seizure activity during and after the quinolone course. Adjust the phenytoin dose based on levels.
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
Frequently asked questions
Can I take Fleroxacin with Phenytoin?
MediHelp rates the interaction as moderate. Fleroxacin 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. Fluoroquinolones have been associated with changes in phenytoin levels, with both reduced and increased concentrations reported. This may lead to loss of seizure control or toxicity. Quinolones may also lower the seizure threshold.
How serious is the interaction between Fleroxacin 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: Monitor serum phenytoin concentrations and seizure activity during and after the quinolone course. Adjust the phenytoin dose based on levels.
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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