Drug interactions
Mefloquine + Quinidine
Severity: Contraindicated
Mefloquine and Quinidine: 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
Both agents prolong the QT interval, and mefloquine may cause conduction abnormalities. Together they raise the risk of serious arrhythmias and cardiac arrest.
What this interaction means in plain words
Mefloquine and Quinidine 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.
Mefloquine belongs to Anti Parasitic; Quinidine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation and conduction effects (pharmacodynamic synergism).
What to do
Avoid the combination; use an alternative antimalarial or antiarrhythmic. If unavoidable, use ECG monitoring and correct electrolytes.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Mefloquine and Quinidine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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 Mefloquine
- Arsenic trioxide + Mefloquine Contraindicated
- Dronedarone + Mefloquine Contraindicated
- Ibutilide + Mefloquine Contraindicated
- Levoketoconazole + Mefloquine Contraindicated
- Mefloquine + Nilotinib Contraindicated
- Mefloquine + Pimozide Contraindicated
Frequently asked questions
Can I take Mefloquine with Quinidine?
MediHelp rates the interaction as contraindicated. Mefloquine and Quinidine 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. Both agents prolong the QT interval, and mefloquine may cause conduction abnormalities. Together they raise the risk of serious arrhythmias and cardiac arrest.
How serious is the interaction between Mefloquine and Quinidine?
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 the combination; use an alternative antimalarial or antiarrhythmic. If unavoidable, use ECG monitoring and correct electrolytes.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
