Drug interactions
Foscarnet + Mobocertinib
Severity: Major
Foscarnet and Mobocertinib: 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
Mobocertinib causes concentration-dependent QT prolongation and has a boxed warning for torsades de pointes. Foscarnet adds to this effect and can cause electrolyte disturbances that further raise arrhythmia risk.
What this interaction means in plain words
Foscarnet and Mobocertinib 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.
Why it happens
Additive QT prolongation, with foscarnet-induced electrolyte disturbances adding to the risk.
What to do
Avoid the combination if possible. If unavoidable, reduce the mobocertinib dose as labeled, monitor ECG more frequently and keep potassium, magnesium and calcium normal.
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
Frequently asked questions
Can I take Foscarnet with Mobocertinib?
MediHelp rates the interaction as major. Foscarnet and Mobocertinib 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. Mobocertinib causes concentration-dependent QT prolongation and has a boxed warning for torsades de pointes. Foscarnet adds to this effect and can cause electrolyte disturbances that further raise arrhythmia risk.
How serious is the interaction between Foscarnet and Mobocertinib?
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 the combination if possible. If unavoidable, reduce the mobocertinib dose as labeled, monitor ECG more frequently and keep potassium, magnesium and calcium normal.
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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