Drug interactions
Phenobarbital + Ziprasidone
Severity: Moderate
Phenobarbital and Ziprasidone: 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 adds to sedation and respiratory depression with ziprasidone. As a CYP3A4 inducer it may lower ziprasidone levels over time, potentially reducing antipsychotic effect.
What this interaction means in plain words
Phenobarbital and Ziprasidone 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 CYP3A4 metabolism of ziprasidone.
What to do
Monitor sedation and psychiatric response, and increase the ziprasidone dose if efficacy falls. Reassess dosing when phenobarbital is stopped.
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 Ziprasidone
- Amiodarone + Ziprasidone Contraindicated
- Amitriptyline + Ziprasidone Contraindicated
- Arsenic trioxide + Ziprasidone Contraindicated
- Bedaquiline + Ziprasidone Contraindicated
- Chloroquine + Ziprasidone Contraindicated
- Citalopram + Ziprasidone Contraindicated
Frequently asked questions
Can I take Phenobarbital with Ziprasidone?
MediHelp rates the interaction as moderate. Phenobarbital and Ziprasidone 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 adds to sedation and respiratory depression with ziprasidone. As a CYP3A4 inducer it may lower ziprasidone levels over time, potentially reducing antipsychotic effect.
How serious is the interaction between Phenobarbital and Ziprasidone?
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 increase the ziprasidone dose if efficacy falls. Reassess dosing when phenobarbital is stopped.
What other medicines interact with Ziprasidone?
MediHelp also lists interactions of Ziprasidone with, for example, Amiodarone, Amitriptyline, Arsenic trioxide. The full list is on the Ziprasidone page.
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