Drug interactions
Foscarnet + Vemurafenib
Severity: Major
Foscarnet and Vemurafenib: 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
Vemurafenib causes concentration-dependent QT prolongation and its labeling advises against use with other QT-prolonging drugs. Foscarnet adds to this effect and can cause electrolyte disturbances that increase the risk of torsade de pointes.
What this interaction means in plain words
Foscarnet and Vemurafenib 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; Vemurafenib belongs to Oncology.
Why it happens
Additive QT prolongation, with foscarnet-related electrolyte disturbances adding risk.
What to do
Avoid the combination if possible. If both are required, monitor ECG and electrolytes regularly and reduce or interrupt vemurafenib if QTc becomes markedly prolonged.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Foscarnet and Vemurafenib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Vemurafenib
Frequently asked questions
Can I take Foscarnet with Vemurafenib?
MediHelp rates the interaction as major. Foscarnet and Vemurafenib 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. Vemurafenib causes concentration-dependent QT prolongation and its labeling advises against use with other QT-prolonging drugs. Foscarnet adds to this effect and can cause electrolyte disturbances that increase the risk of torsade de pointes.
How serious is the interaction between Foscarnet and Vemurafenib?
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 both are required, monitor ECG and electrolytes regularly and reduce or interrupt vemurafenib if QTc becomes markedly prolonged.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
