Drug interactions
Perphenazine + Phenobarbital
Severity: Moderate
Perphenazine 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 depresses the CNS and combined with perphenazine can cause marked sedation and hypotension. Phenobarbital also induces hepatic enzymes and may lower perphenazine levels, while perphenazine can lower the seizure threshold in patients with epilepsy.
What this interaction means in plain words
Perphenazine 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 and induction of CYP-mediated perphenazine metabolism by phenobarbital.
What to do
Monitor sedation and psychiatric response, and adjust perphenazine dose if efficacy falls. Monitor seizure control in patients with epilepsy.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Perphenazine with Phenobarbital?
MediHelp rates the interaction as moderate. Perphenazine 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 depresses the CNS and combined with perphenazine can cause marked sedation and hypotension. Phenobarbital also induces hepatic enzymes and may lower perphenazine levels, while perphenazine can lower the seizure threshold in patients with epilepsy.
How serious is the interaction between Perphenazine 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 perphenazine dose if efficacy falls. Monitor seizure control in patients with epilepsy.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine page.
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