Drug interactions
Doxepin + Foscarnet
Severity: Moderate
Doxepin and Foscarnet: 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
Both drugs have been associated with QT prolongation, and foscarnet may disturb electrolytes that protect against arrhythmia. The combined risk of ventricular arrhythmia is modestly increased, particularly at higher doses or with other risk factors.
What this interaction means in plain words
Doxepin and Foscarnet 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.
Doxepin belongs to Dermatology; Foscarnet belongs to Anti Virals.
Why it happens
Additive QT prolongation with foscarnet-related electrolyte loss.
What to do
Obtain a baseline ECG in patients with cardiac risk factors and monitor QTc. Correct potassium, magnesium and calcium abnormalities.
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 Foscarnet
- Cidofovir + Foscarnet Contraindicated
- Foscarnet + Pimozide Contraindicated
- Foscarnet + Thioridazine Contraindicated
- Foscarnet + Vandetanib Contraindicated
- Adagrasib + Foscarnet Major
- Adefovir + Foscarnet Major
Other interactions of Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Doxepin with Foscarnet?
MediHelp rates the interaction as moderate. Doxepin and Foscarnet 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. Both drugs have been associated with QT prolongation, and foscarnet may disturb electrolytes that protect against arrhythmia. The combined risk of ventricular arrhythmia is modestly increased, particularly at higher doses or with other risk factors.
How serious is the interaction between Doxepin and Foscarnet?
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 in patients with cardiac risk factors and monitor QTc. Correct potassium, magnesium and calcium abnormalities.
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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