Drug interactions
Daridorexant + Phenytoin
Severity: Major
Daridorexant and Phenytoin: major 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 markedly lower daridorexant exposure, reducing its hypnotic effect.
What this interaction means in plain words
Daridorexant and Phenytoin 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.
Daridorexant belongs to Central Nervous System; Phenytoin belongs to Central Nervous System.
Why it happens
CYP3A4 induction by phenytoin increases daridorexant clearance.
What to do
Avoid the combination, as labeling advises against strong CYP3A4 inducers. Consider a different insomnia treatment.
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?
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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
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Other interactions of Daridorexant
Frequently asked questions
Can I take Daridorexant with Phenytoin?
MediHelp rates the interaction as major. Daridorexant and Phenytoin 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. Phenytoin is expected to markedly lower daridorexant exposure, reducing its hypnotic effect.
How serious is the interaction between Daridorexant and Phenytoin?
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, as labeling advises against strong CYP3A4 inducers. Consider a different insomnia treatment.
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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