Drug interactions
Carbamazepine + Diazepam
Severity: Moderate
Carbamazepine and Diazepam: 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
Carbamazepine induces CYP3A4, speeding up diazepam and desmethyldiazepam metabolism and lowering benzodiazepine concentrations. This can reduce seizure control or anxiolytic effect, and the sedative effects of both drugs may add together.
What this interaction means in plain words
Carbamazepine and Diazepam 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.
Carbamazepine belongs to Central Nervous System; Diazepam belongs to Musculoskeletal.
Why it happens
CYP3A4 induction by carbamazepine increases diazepam clearance.
What to do
Monitor clinical response and adjust the diazepam dose upward if needed. Watch for sedation and review doses when carbamazepine is started 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?
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Other interactions of Diazepam
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Diazepam?
MediHelp rates the interaction as moderate. Carbamazepine and Diazepam 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. Carbamazepine induces CYP3A4, speeding up diazepam and desmethyldiazepam metabolism and lowering benzodiazepine concentrations. This can reduce seizure control or anxiolytic effect, and the sedative effects of both drugs may add together.
How serious is the interaction between Carbamazepine and Diazepam?
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 clinical response and adjust the diazepam dose upward if needed. Watch for sedation and review doses when carbamazepine is started or stopped.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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