Drug interactions
Fluphenazine + Phenobarbital
Severity: Moderate
Fluphenazine 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 and fluphenazine both depress the central nervous system, so combined use can cause excessive sedation, impaired psychomotor performance and respiratory depression. Phenobarbital is also a strong enzyme inducer and may reduce fluphenazine concentrations. Antipsychotics can lower the seizure threshold, which complicates anticonvulsant use.
What this interaction means in plain words
Fluphenazine 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 CNS depression, with phenobarbital-induced hepatic metabolism of fluphenazine.
What to do
Monitor sedation and psychiatric response, and adjust fluphenazine dose if symptoms recur. Watch seizure control when using the antipsychotic.
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 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 Phenobarbital?
MediHelp rates the interaction as moderate. Fluphenazine 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 and fluphenazine both depress the central nervous system, so combined use can cause excessive sedation, impaired psychomotor performance and respiratory depression. Phenobarbital is also a strong enzyme inducer and may reduce fluphenazine concentrations. Antipsychotics can lower the seizure threshold, which complicates anticonvulsant use.
How serious is the interaction between Fluphenazine 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 sedation and psychiatric response, and adjust fluphenazine dose if symptoms recur. Watch seizure control when using the antipsychotic.
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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