Drug interactions
Fluphenazine + Foscarnet
Severity: Major
Fluphenazine and Foscarnet: 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
Both drugs may prolong the QT interval, and foscarnet may cause hypocalcemia and hypomagnesemia. The combination increases the risk of torsades de pointes.
What this interaction means in plain words
Fluphenazine and Foscarnet 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.
Fluphenazine belongs to Central Nervous System; Foscarnet belongs to Anti Virals.
Why it happens
Additive QT prolongation, worsened by electrolyte depletion.
What to do
Check baseline and follow-up ECG, maintain normal electrolytes, and consider an alternative antipsychotic if QTc prolongs.
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 Foscarnet
- Cidofovir + Foscarnet Contraindicated
- Foscarnet + Pimozide Contraindicated
- Foscarnet + Thioridazine Contraindicated
- Foscarnet + Vandetanib Contraindicated
- Adagrasib + Foscarnet Major
- Adefovir + Foscarnet Major
Other interactions of Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Foscarnet?
MediHelp rates the interaction as major. Fluphenazine and Foscarnet 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. Both drugs may prolong the QT interval, and foscarnet may cause hypocalcemia and hypomagnesemia. The combination increases the risk of torsades de pointes.
How serious is the interaction between Fluphenazine and Foscarnet?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check baseline and follow-up ECG, maintain normal electrolytes, and consider an alternative antipsychotic if QTc prolongs.
What other medicines interact with Foscarnet?
MediHelp also lists interactions of Foscarnet with, for example, Cidofovir, Pimozide, Thioridazine. The full list is on the Foscarnet page.
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