Drug interactions
Elbasvir / grazoprevir + Phenytoin
Severity: Contraindicated
Elbasvir / grazoprevir 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 is expected to reduce elbasvir and grazoprevir concentrations, increasing the risk of hepatitis C treatment failure.
What this interaction means in plain words
Elbasvir / grazoprevir 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 and P-glycoprotein, which clear both components.
What to do
Do not co-administer; use a non-inducing anticonvulsant or choose another HCV regimen compatible with phenytoin.
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
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
- Ensitrelvir + Phenytoin Contraindicated
Frequently asked questions
Can I take Elbasvir / grazoprevir with Phenytoin?
MediHelp rates the interaction as contraindicated. Elbasvir / grazoprevir 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 is expected to reduce elbasvir and grazoprevir concentrations, increasing the risk of hepatitis C treatment failure.
How serious is the interaction between Elbasvir / grazoprevir 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 co-administer; use a non-inducing anticonvulsant or choose another HCV regimen compatible with phenytoin.
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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