Drug interactions
Phenytoin + Rimegepant
Severity: Moderate
Phenytoin and Rimegepant: 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
Phenytoin may markedly reduce rimegepant exposure and thus weaken its effect on migraine. Rimegepant labeling recommends avoiding strong or moderate CYP3A inducers.
What this interaction means in plain words
Phenytoin and Rimegepant 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.
Phenytoin belongs to Central Nervous System; Rimegepant belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4, increasing the metabolism of rimegepant.
What to do
Avoid the combination where possible and use a different migraine therapy or a non-inducing antiseizure drug. If used together, watch for loss of migraine efficacy.
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 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 Rimegepant
Frequently asked questions
Can I take Phenytoin with Rimegepant?
MediHelp rates the interaction as moderate. Phenytoin and Rimegepant 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. Phenytoin may markedly reduce rimegepant exposure and thus weaken its effect on migraine. Rimegepant labeling recommends avoiding strong or moderate CYP3A inducers.
How serious is the interaction between Phenytoin and Rimegepant?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use a different migraine therapy or a non-inducing antiseizure drug. If used together, watch for loss of migraine efficacy.
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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