Drug interactions
Artemether / lumefantrine + Phenytoin
Severity: Contraindicated
Artemether / lumefantrine 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 a strong inducer of CYP3A4 and can markedly lower artemether and lumefantrine concentrations. This may lead to treatment failure of malaria and promote recrudescence or resistance.
What this interaction means in plain words
Artemether / lumefantrine 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
Induction of CYP3A4-mediated metabolism of artemether and lumefantrine by phenytoin.
What to do
Avoid the combination and choose an antimalarial or anticonvulsant that is not a strong enzyme inducer. If unavoidable, seek specialist advice and monitor parasitological response closely.
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
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
- Ensitrelvir + Phenytoin Contraindicated
Frequently asked questions
Can I take Artemether / lumefantrine with Phenytoin?
MediHelp rates the interaction as contraindicated. Artemether / lumefantrine 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 a strong inducer of CYP3A4 and can markedly lower artemether and lumefantrine concentrations. This may lead to treatment failure of malaria and promote recrudescence or resistance.
How serious is the interaction between Artemether / lumefantrine 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: Avoid the combination and choose an antimalarial or anticonvulsant that is not a strong enzyme inducer. If unavoidable, seek specialist advice and monitor parasitological response closely.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Bictegravir, Cabotegravir, Doravirine. The full list is on the Phenytoin page.
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