Drug interactions
Flurazepam + Phenytoin
Severity: Minor
Flurazepam and Phenytoin: minor 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 reduce flurazepam active metabolite exposure and its hypnotic effect. Benzodiazepines can also alter phenytoin levels unpredictably, and additive sedation is possible.
What this interaction means in plain words
Flurazepam and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Phenytoin induces CYP3A4, increasing flurazepam metabolism.
What to do
Monitor sedative response and increase the flurazepam dose only if needed. Check phenytoin levels if toxicity or breakthrough seizures occur.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Flurazepam with Phenytoin?
MediHelp rates the interaction as minor. Flurazepam and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Phenytoin may reduce flurazepam active metabolite exposure and its hypnotic effect. Benzodiazepines can also alter phenytoin levels unpredictably, and additive sedation is possible.
How serious is the interaction between Flurazepam and Phenytoin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor sedative response and increase the flurazepam dose only if needed. Check phenytoin levels if toxicity or breakthrough seizures occur.
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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