Drug interactions
Fluphenazine + Pentobarbital
Severity: Major
Fluphenazine 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
Pentobarbital is a barbiturate with strong sedative effects, and fluphenazine adds further central depression. Combined use can cause marked drowsiness, hypotension and respiratory depression. Barbiturates also induce hepatic enzymes and may lower fluphenazine exposure over time.
What this interaction means in plain words
Fluphenazine 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, plus possible CYP induction by barbiturates reducing phenothiazine levels.
What to do
Use the lowest effective doses and monitor sedation, respiration and blood pressure. Watch for loss of antipsychotic efficacy during 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?
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References
Other interactions of Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Fluphenazine with Pentobarbital?
MediHelp rates the interaction as major. Fluphenazine 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. Pentobarbital is a barbiturate with strong sedative effects, and fluphenazine adds further central depression. Combined use can cause marked drowsiness, hypotension and respiratory depression. Barbiturates also induce hepatic enzymes and may lower fluphenazine exposure over time.
How serious is the interaction between Fluphenazine 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, respiration and blood pressure. Watch for loss of antipsychotic efficacy during prolonged barbiturate use.
What other medicines interact with Fluphenazine?
MediHelp also lists interactions of Fluphenazine with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Fluphenazine page.
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