Drug interactions
Primaquine + Primidone
Severity: Moderate
Primaquine 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
Primidone is metabolised to phenobarbital, an enzyme inducer, which may lower primaquine exposure and reduce its efficacy. The effect is predicted from the mechanism rather than well documented.
What this interaction means in plain words
Primaquine 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.
Primaquine belongs to Anti Parasitic; Primidone belongs to Central Nervous System.
Why it happens
Phenobarbital-mediated induction of CYP enzymes including CYP3A4 increases primaquine clearance.
What to do
Monitor for malaria relapse or treatment failure. Consider a non-inducing anticonvulsant if clinically appropriate.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
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 Primaquine with Primidone?
MediHelp rates the interaction as moderate. Primaquine 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. Primidone is metabolised to phenobarbital, an enzyme inducer, which may lower primaquine exposure and reduce its efficacy. The effect is predicted from the mechanism rather than well documented.
How serious is the interaction between Primaquine 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 for malaria relapse or treatment failure. Consider a non-inducing anticonvulsant if clinically appropriate.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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