Drug interactions
Midazolam intranasal + Phenytoin
Severity: Moderate
Midazolam intranasal and Phenytoin: 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
Midazolam is a potent CNS and respiratory depressant, and phenytoin can add to sedation. Phenytoin may also lower midazolam levels through CYP3A4 induction. The net effect is variable but oversedation is possible.
What this interaction means in plain words
Midazolam intranasal and Phenytoin 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.
Why it happens
Additive CNS depression, with phenytoin CYP3A4 induction possibly reducing midazolam exposure.
What to do
Monitor respiratory rate, oxygen saturation and level of consciousness after dosing. Be prepared to give a repeat dose if seizure control is inadequate, per local protocol.
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
Frequently asked questions
Can I take Midazolam intranasal with Phenytoin?
MediHelp rates the interaction as moderate. Midazolam intranasal and Phenytoin 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. Midazolam is a potent CNS and respiratory depressant, and phenytoin can add to sedation. Phenytoin may also lower midazolam levels through CYP3A4 induction. The net effect is variable but oversedation is possible.
How serious is the interaction between Midazolam intranasal and Phenytoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor respiratory rate, oxygen saturation and level of consciousness after dosing. Be prepared to give a repeat dose if seizure control is inadequate, per local protocol.
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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