Drug interactions
Clorazepate + Phenytoin
Severity: Moderate
Clorazepate 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
Phenytoin induces hepatic enzymes and may lower plasma levels of the active metabolite of clorazepate, reducing its effect. Clorazepate may also alter phenytoin concentrations unpredictably, and both drugs are sedating.
What this interaction means in plain words
Clorazepate 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.
Clorazepate belongs to Central Nervous System; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4 and CYP2C enzymes, increasing the metabolism of benzodiazepines; benzodiazepines may variably change phenytoin levels.
What to do
Monitor seizure control and anxiolytic response, and increase the clorazepate dose if needed. Check phenytoin levels when clorazepate is started, changed or stopped.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clorazepate and Phenytoin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Clorazepate
- Calcium / magnesium / potassium / sodium oxybates + Clorazepate Contraindicated
- Clorazepate + Sodium oxybate Contraindicated
- Alfentanil + Clorazepate Major
- Alprazolam + Clorazepate Major
- Amobarbital + Clorazepate Major
- Belladonna and opium + Clorazepate Major
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 Clorazepate with Phenytoin?
MediHelp rates the interaction as moderate. Clorazepate 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. Phenytoin induces hepatic enzymes and may lower plasma levels of the active metabolite of clorazepate, reducing its effect. Clorazepate may also alter phenytoin concentrations unpredictably, and both drugs are sedating.
How serious is the interaction between Clorazepate 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 seizure control and anxiolytic response, and increase the clorazepate dose if needed. Check phenytoin levels when clorazepate is started, changed or stopped.
What other medicines interact with Clorazepate?
MediHelp also lists interactions of Clorazepate with, for example, Calcium / magnesium / potassium / sodium oxybates, Sodium oxybate, Alfentanil. The full list is on the Clorazepate page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
