Drug interactions
Foscarnet + Perphenazine
Severity: Major
Foscarnet and Perphenazine: 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
Perphenazine and foscarnet may both prolong the QT interval, and foscarnet-induced electrolyte loss adds risk. This increases the possibility of torsades de pointes.
What this interaction means in plain words
Foscarnet and Perphenazine 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; Perphenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation aggravated by electrolyte depletion.
What to do
Check baseline ECG, monitor QTc and electrolytes, and consider an alternative antipsychotic if QTc lengthens.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Foscarnet with Perphenazine?
MediHelp rates the interaction as major. Foscarnet and Perphenazine 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. Perphenazine and foscarnet may both prolong the QT interval, and foscarnet-induced electrolyte loss adds risk. This increases the possibility of torsades de pointes.
How serious is the interaction between Foscarnet and Perphenazine?
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 ECG, monitor QTc and electrolytes, and consider an alternative antipsychotic if QTc lengthens.
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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