Drug interactions
Primidone + Quinidine
Severity: Moderate
Primidone and Quinidine: 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
Primidone is metabolized to phenobarbital and induces hepatic enzymes, which can lower quinidine concentrations and reduce efficacy.
What this interaction means in plain words
Primidone and Quinidine 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.
Primidone belongs to Central Nervous System; Quinidine belongs to Anti Parasitic.
Why it happens
Primidone and its metabolite phenobarbital induce CYP3A4, increasing quinidine clearance.
What to do
Monitor quinidine levels and ECG response and raise the dose if needed. Reduce the dose again if primidone 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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine 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 Primidone with Quinidine?
MediHelp rates the interaction as moderate. Primidone and Quinidine 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. Primidone is metabolized to phenobarbital and induces hepatic enzymes, which can lower quinidine concentrations and reduce efficacy.
How serious is the interaction between Primidone and Quinidine?
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 quinidine levels and ECG response and raise the dose if needed. Reduce the dose again if primidone is stopped.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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