Drug interactions
Chlordiazepoxide + Pentobarbital
Severity: Major
Chlordiazepoxide and Pentobarbital: major interaction.
Last updated Sources: UK SmPC
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
Combining a benzodiazepine with a barbiturate produces additive sedation and may cause respiratory depression and hypotension. Pentobarbital may also lower chlordiazepoxide exposure through enzyme induction.
What this interaction means in plain words
Chlordiazepoxide and Pentobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive GABA-A mediated CNS depression, with barbiturate induction of hepatic CYP enzymes altering benzodiazepine clearance.
What to do
Avoid concurrent use unless clinically necessary, and reduce doses accordingly. Monitor sedation, respiration and blood pressure, particularly in debilitated or elderly patients.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
- Librium 10 mg Capsules - SmPC sections 4.3/4.5 (class statement: barbiturates; "particularly with hydantoins or barbiturates or combinations including them.") — electronic medicines compendium (UK SmPC)
Other interactions of Chlordiazepoxide
Frequently asked questions
Can I take Chlordiazepoxide with Pentobarbital?
MediHelp rates the interaction as major. Chlordiazepoxide and Pentobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Combining a benzodiazepine with a barbiturate produces additive sedation and may cause respiratory depression and hypotension. Pentobarbital may also lower chlordiazepoxide exposure through enzyme induction.
How serious is the interaction between Chlordiazepoxide and Pentobarbital?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use unless clinically necessary, and reduce doses accordingly. Monitor sedation, respiration and blood pressure, particularly in debilitated or elderly patients.
What other medicines interact with Chlordiazepoxide?
MediHelp also lists interactions of Chlordiazepoxide with, for example, Alfentanil, Alprazolam, Amobarbital. The full list is on the Chlordiazepoxide page.
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