Drug interactions
Floxuridine + Quinidine
Severity: Moderate
Floxuridine and Quinidine: 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
Quinidine clearly prolongs the QT interval. Floxuridine is a fluoropyrimidine, and fluoropyrimidines have been linked to cardiotoxicity, but QT prolongation with floxuridine is poorly documented, so the additive effect is uncertain. Caution is still sensible given quinidine's torsades risk.
What this interaction means in plain words
Floxuridine and Quinidine 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
Possible additive QT prolongation; the contribution of floxuridine is not well established.
What to do
Obtain a baseline ECG and monitor QTc and electrolytes (potassium, magnesium) during combined use. Consider an alternative to quinidine if QTc lengthens.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Floxuridine with Quinidine?
MediHelp rates the interaction as moderate. Floxuridine and Quinidine 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. Quinidine clearly prolongs the QT interval. Floxuridine is a fluoropyrimidine, and fluoropyrimidines have been linked to cardiotoxicity, but QT prolongation with floxuridine is poorly documented, so the additive effect is uncertain. Caution is still sensible given quinidine's torsades risk.
How serious is the interaction between Floxuridine and Quinidine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and monitor QTc and electrolytes (potassium, magnesium) during combined use. Consider an alternative to quinidine if QTc lengthens.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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