Drug interactions
Foscarnet + Gemifloxacin
Severity: Major
Foscarnet and Gemifloxacin: major interaction.
Last updated Sources: US FDA label
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
Foscarnet can prolong the QT interval and cause electrolyte disturbances such as low calcium, magnesium, and potassium. With gemifloxacin this increases the risk of torsades de pointes.
What this interaction means in plain words
Foscarnet and Gemifloxacin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Foscarnet belongs to Anti Virals; Gemifloxacin belongs to Anti Bacterial.
Why it happens
Additive QT prolongation, compounded by foscarnet-induced electrolyte depletion.
What to do
Avoid if an alternative antibiotic is available. If used together, monitor ECG and serum calcium, magnesium, and potassium, and replace as needed.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
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 Foscarnet
- Cidofovir + Foscarnet Contraindicated
- Foscarnet + Pimozide Contraindicated
- Foscarnet + Thioridazine Contraindicated
- Foscarnet + Vandetanib Contraindicated
- Adagrasib + Foscarnet Major
- Adefovir + Foscarnet Major
Frequently asked questions
Can I take Foscarnet with Gemifloxacin?
MediHelp rates the interaction as major. Foscarnet and Gemifloxacin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Foscarnet can prolong the QT interval and cause electrolyte disturbances such as low calcium, magnesium, and potassium. With gemifloxacin this increases the risk of torsades de pointes.
How serious is the interaction between Foscarnet and Gemifloxacin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if an alternative antibiotic is available. If used together, monitor ECG and serum calcium, magnesium, and potassium, and replace as needed.
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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