Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin
Severity: Contraindicated
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Phenytoin: contraindicated 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
Phenytoin lowers elvitegravir and cobicistat exposure, which may cause loss of virologic control and resistance.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df and Phenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Phenytoin induces CYP3A4 metabolism of elvitegravir and cobicistat.
What to do
Do not use together; choose a different antiretroviral regimen or a non-inducing anticonvulsant.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Ensitrelvir + Phenytoin Contraindicated
Frequently asked questions
Can I take Elvitegravir / cobicistat / emtricitabine / tenofovir df with Phenytoin?
MediHelp rates the interaction as contraindicated. Elvitegravir / cobicistat / emtricitabine / tenofovir df and Phenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Phenytoin lowers elvitegravir and cobicistat exposure, which may cause loss of virologic control and resistance.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df and Phenytoin?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not use together; choose a different antiretroviral regimen or a non-inducing anticonvulsant.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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