Drug interactions
Phenobarbital + Pimozide
Severity: Moderate
Phenobarbital and Pimozide: 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 pimozide both depress the CNS, increasing drowsiness and impaired coordination. Phenobarbital also induces CYP3A4 and can lower pimozide concentrations over time, potentially reducing efficacy.
What this interaction means in plain words
Phenobarbital and Pimozide 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, plus phenobarbital induction of CYP3A4 metabolism of pimozide.
What to do
Monitor for sedation and for reduced pimozide response, and titrate pimozide to clinical effect. Re-evaluate dosing if phenobarbital is started or 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 Pimozide
- Adagrasib + Pimozide Contraindicated
- Amiodarone + Pimozide Contraindicated
- Amisulpride + Pimozide Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amoxapine + Pimozide Contraindicated
- Anagrelide + Pimozide Contraindicated
Frequently asked questions
Can I take Phenobarbital with Pimozide?
MediHelp rates the interaction as moderate. Phenobarbital and Pimozide 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 pimozide both depress the CNS, increasing drowsiness and impaired coordination. Phenobarbital also induces CYP3A4 and can lower pimozide concentrations over time, potentially reducing efficacy.
How serious is the interaction between Phenobarbital and Pimozide?
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 for sedation and for reduced pimozide response, and titrate pimozide to clinical effect. Re-evaluate dosing if phenobarbital is started or stopped.
What other medicines interact with Pimozide?
MediHelp also lists interactions of Pimozide with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Pimozide page.
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