Drug interactions
Chlorpromazine + Pentobarbital
Severity: Major
Chlorpromazine and Pentobarbital: major interaction.
Last updated Sources: US FDA label
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
Barbiturates and chlorpromazine both depress the CNS, so profound sedation, hypotension and respiratory depression can occur. Barbiturates may also induce hepatic enzymes and lower chlorpromazine levels over time, and chlorpromazine can lower the seizure threshold.
What this interaction means in plain words
Chlorpromazine 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 CNS depression, with enzyme induction by barbiturates that can reduce phenothiazine exposure.
What to do
Use the lowest effective doses and monitor sedation, respiratory status and blood pressure. Watch for reduced antipsychotic effect with prolonged barbiturate use.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chlorpromazine and Pentobarbital, 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.
References
Other interactions of Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Frequently asked questions
Can I take Chlorpromazine with Pentobarbital?
MediHelp rates the interaction as major. Chlorpromazine 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. Barbiturates and chlorpromazine both depress the CNS, so profound sedation, hypotension and respiratory depression can occur. Barbiturates may also induce hepatic enzymes and lower chlorpromazine levels over time, and chlorpromazine can lower the seizure threshold.
How serious is the interaction between Chlorpromazine 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: Use the lowest effective doses and monitor sedation, respiratory status and blood pressure. Watch for reduced antipsychotic effect with prolonged barbiturate use.
What other medicines interact with Chlorpromazine?
MediHelp also lists interactions of Chlorpromazine with, for example, Dofetilide, Dronedarone, Droperidol. The full list is on the Chlorpromazine 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.
