Drug interactions
Mefloquine + Primidone
Severity: Major
Mefloquine and Primidone: major 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 CYP3A4 and may lower mefloquine concentrations, which may compromise antimalarial efficacy. Mefloquine can also reduce seizure threshold in patients treated with primidone for epilepsy.
What this interaction means in plain words
Mefloquine and Primidone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Mefloquine belongs to Anti Parasitic; Primidone belongs to Central Nervous System.
Why it happens
CYP3A4 induction increases mefloquine metabolism, and mefloquine has proconvulsant effects.
What to do
Prefer an alternative antimalarial in patients taking primidone. If unavoidable, monitor for treatment failure and loss of seizure control.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Mefloquine
- Arsenic trioxide + Mefloquine Contraindicated
- Dronedarone + Mefloquine Contraindicated
- Ibutilide + Mefloquine Contraindicated
- Levoketoconazole + Mefloquine Contraindicated
- Mefloquine + Nilotinib Contraindicated
- Mefloquine + 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 Mefloquine with Primidone?
MediHelp rates the interaction as major. Mefloquine and Primidone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Primidone, partly metabolized to phenobarbital, induces CYP3A4 and may lower mefloquine concentrations, which may compromise antimalarial efficacy. Mefloquine can also reduce seizure threshold in patients treated with primidone for epilepsy.
How serious is the interaction between Mefloquine and Primidone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an alternative antimalarial in patients taking primidone. If unavoidable, monitor for treatment failure and loss of seizure control.
What other medicines interact with Mefloquine?
MediHelp also lists interactions of Mefloquine with, for example, Arsenic trioxide, Dronedarone, Ibutilide. The full list is on the Mefloquine page.
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