Drug interactions
Primidone + Voriconazole
Severity: Contraindicated
Primidone and Voriconazole: contraindicated 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
Primidone, partly metabolized to phenobarbital, induces enzymes and can lower voriconazole to subtherapeutic levels, risking failure of antifungal therapy.
What this interaction means in plain words
Primidone and Voriconazole are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Primidone belongs to Central Nervous System; Voriconazole belongs to Anti Fungals.
Why it happens
Induction of CYP2C19, CYP2C9 and CYP3A4 by primidone and its phenobarbital metabolite increases voriconazole clearance.
What to do
Avoid concomitant use; select a non-inducing anticonvulsant. Voriconazole labeling lists this combination as contraindicated.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole Contraindicated
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Abiraterone + Primidone Major
- Amitriptyline + Primidone Major
Frequently asked questions
Can I take Primidone with Voriconazole?
MediHelp rates the interaction as contraindicated. Primidone and Voriconazole are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Primidone, partly metabolized to phenobarbital, induces enzymes and can lower voriconazole to subtherapeutic levels, risking failure of antifungal therapy.
How serious is the interaction between Primidone and Voriconazole?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concomitant use; select a non-inducing anticonvulsant. Voriconazole labeling lists this combination as contraindicated.
What other medicines interact with Voriconazole?
MediHelp also lists interactions of Voriconazole with, for example, Avanafil, Butabarbital, Carbamazepine. The full list is on the Voriconazole page.
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