Drug interactions
Clorazepate + Phenobarbital
Severity: Moderate
Clorazepate and Phenobarbital: 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
Phenobarbital adds to the CNS depressant effects of clorazepate, increasing sedation and the risk of respiratory depression. As a CYP3A4 inducer it may also lower exposure to the active metabolite of clorazepate over time, which can reduce benzodiazepine effect and complicate dosing.
What this interaction means in plain words
Clorazepate and Phenobarbital 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 GABA-A mediated CNS depression plus induction of CYP3A4 metabolism by phenobarbital.
What to do
Monitor for oversedation and respiratory depression, and for loss of anxiolytic or anticonvulsant effect. Adjust the clorazepate dose according to clinical response.
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 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
Frequently asked questions
Can I take Clorazepate with Phenobarbital?
MediHelp rates the interaction as moderate. Clorazepate and Phenobarbital 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. Phenobarbital adds to the CNS depressant effects of clorazepate, increasing sedation and the risk of respiratory depression. As a CYP3A4 inducer it may also lower exposure to the active metabolite of clorazepate over time, which can reduce benzodiazepine effect and complicate dosing.
How serious is the interaction between Clorazepate and Phenobarbital?
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 for oversedation and respiratory depression, and for loss of anxiolytic or anticonvulsant effect. Adjust the clorazepate dose according to clinical response.
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.
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