Drug interactions
Lithium + Mefloquine
Severity: Moderate
Lithium and Mefloquine: 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
Lithium has been associated with QT prolongation and arrhythmia, particularly at toxic concentrations, and mefloquine may add to this effect. Both drugs can also cause neuropsychiatric effects, which may complicate assessment.
What this interaction means in plain words
Lithium and Mefloquine 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.
Lithium belongs to Central Nervous System; Mefloquine belongs to Anti Parasitic.
Why it happens
Additive effects on cardiac repolarization and overlapping neuropsychiatric toxicity.
What to do
Obtain a baseline ECG and monitor serum lithium, electrolytes and mental status; consider an alternative antimalarial for prophylaxis if the patient has cardiac 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 Mefloquine
- Arsenic trioxide + Mefloquine Contraindicated
- Dronedarone + Mefloquine Contraindicated
- Ibutilide + Mefloquine Contraindicated
- Levoketoconazole + Mefloquine Contraindicated
- Mefloquine + Nilotinib Contraindicated
- Mefloquine + Pimozide Contraindicated
Other interactions of Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Lithium with Mefloquine?
MediHelp rates the interaction as moderate. Lithium and Mefloquine 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. Lithium has been associated with QT prolongation and arrhythmia, particularly at toxic concentrations, and mefloquine may add to this effect. Both drugs can also cause neuropsychiatric effects, which may complicate assessment.
How serious is the interaction between Lithium and Mefloquine?
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 monitor serum lithium, electrolytes and mental status; consider an alternative antimalarial for prophylaxis if the patient has cardiac risk factors.
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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