Drug interactions
Fosphenytoin + Gemifloxacin
Severity: Moderate
Fosphenytoin and Gemifloxacin: 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 reported to alter phenytoin concentrations, with both decreases and increases described in isolated cases. Changes in phenytoin levels can cause loss of seizure control or toxicity such as ataxia and nystagmus.
What this interaction means in plain words
Fosphenytoin and Gemifloxacin 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.
Fosphenytoin belongs to Central Nervous System; Gemifloxacin belongs to Anti Bacterial.
Why it happens
The mechanism is not well established; the effect on phenytoin levels is variable and may involve altered metabolism or absorption.
What to do
Monitor phenytoin concentrations and seizure control during and after the antibiotic course. Adjust the fosphenytoin dose according to levels and clinical signs.
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 Gemifloxacin
- Arsenic trioxide + Gemifloxacin Contraindicated
- Dofetilide + Gemifloxacin Contraindicated
- Gemifloxacin + Ibutilide Contraindicated
- Gemifloxacin + Pimozide Contraindicated
- Gemifloxacin + Thioridazine Contraindicated
- Gemifloxacin + Vandetanib Contraindicated
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Gemifloxacin?
MediHelp rates the interaction as moderate. Fosphenytoin and Gemifloxacin 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 reported to alter phenytoin concentrations, with both decreases and increases described in isolated cases. Changes in phenytoin levels can cause loss of seizure control or toxicity such as ataxia and nystagmus.
How serious is the interaction between Fosphenytoin and Gemifloxacin?
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 phenytoin concentrations and seizure control during and after the antibiotic course. Adjust the fosphenytoin dose according to levels and clinical signs.
What other medicines interact with Gemifloxacin?
MediHelp also lists interactions of Gemifloxacin with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Gemifloxacin page.
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