Drug interactions
Mefloquine + Primaquine
Severity: Moderate
Mefloquine and Primaquine: 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
Both drugs can prolong the QT interval, so using them together may add to the risk of ventricular arrhythmias including torsades de pointes. Mefloquine can also cause conduction abnormalities, which adds to the concern.
What this interaction means in plain words
Mefloquine and Primaquine 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.
Mefloquine belongs to Anti Parasitic; Primaquine belongs to Anti Parasitic.
Why it happens
Additive pharmacodynamic QT prolongation through cardiac repolarization effects.
What to do
Obtain a baseline ECG and correct hypokalemia and hypomagnesemia before starting. Consider an alternative antimalarial if the QTc is prolonged or the patient has other risk factors.
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 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 Primaquine?
MediHelp rates the interaction as moderate. Mefloquine and Primaquine 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. Both drugs can prolong the QT interval, so using them together may add to the risk of ventricular arrhythmias including torsades de pointes. Mefloquine can also cause conduction abnormalities, which adds to the concern.
How serious is the interaction between Mefloquine and Primaquine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and correct hypokalemia and hypomagnesemia before starting. Consider an alternative antimalarial if the QTc is prolonged or the patient has other risk factors.
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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