Drug interactions
Pimozide + Primidone
Severity: Moderate
Pimozide and Primidone: 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
Both drugs cause CNS depression, which can increase drowsiness and impair alertness. Primidone is metabolised to phenobarbital, a CYP3A4 inducer, which may lower pimozide levels and reduce its effect.
What this interaction means in plain words
Pimozide and Primidone 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.
Pimozide belongs to Central Nervous System; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression, plus CYP3A4 induction by primidone/phenobarbital.
What to do
Monitor sedation and therapeutic response to pimozide, and adjust pimozide dose to effect. Re-evaluate if primidone 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
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Pimozide with Primidone?
MediHelp rates the interaction as moderate. Pimozide and Primidone 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. Both drugs cause CNS depression, which can increase drowsiness and impair alertness. Primidone is metabolised to phenobarbital, a CYP3A4 inducer, which may lower pimozide levels and reduce its effect.
How serious is the interaction between Pimozide and Primidone?
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 therapeutic response to pimozide, and adjust pimozide dose to effect. Re-evaluate if primidone 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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