Drug interactions
Arsenic trioxide + Mefloquine
Severity: Contraindicated
Arsenic trioxide and Mefloquine: 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
Arsenic trioxide carries a boxed warning for QT prolongation, torsades de pointes and complete AV block, and mefloquine adds to this risk. The combination can lead to life-threatening arrhythmias.
What this interaction means in plain words
Arsenic trioxide and Mefloquine 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.
Arsenic trioxide belongs to Oncology; Mefloquine belongs to Anti Parasitic.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Do not use together; choose a non-QT-prolonging antimalarial for prophylaxis or treatment. If unavoidable, use intensive ECG and electrolyte monitoring.
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?
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Other interactions of Mefloquine
- Dronedarone + Mefloquine Contraindicated
- Ibutilide + Mefloquine Contraindicated
- Levoketoconazole + Mefloquine Contraindicated
- Mefloquine + Nilotinib Contraindicated
- Mefloquine + Pimozide Contraindicated
- Mefloquine + Quinidine Contraindicated
Other interactions of Arsenic trioxide
- Amiodarone + Arsenic trioxide Contraindicated
- Amisulpride + Arsenic trioxide Contraindicated
- Arsenic trioxide + Clomipramine Contraindicated
- Arsenic trioxide + Dronedarone Contraindicated
- Arsenic trioxide + Fluphenazine Contraindicated
- Arsenic trioxide + Gemifloxacin Contraindicated
Frequently asked questions
Can I take Arsenic trioxide with Mefloquine?
MediHelp rates the interaction as contraindicated. Arsenic trioxide and Mefloquine 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. Arsenic trioxide carries a boxed warning for QT prolongation, torsades de pointes and complete AV block, and mefloquine adds to this risk. The combination can lead to life-threatening arrhythmias.
How serious is the interaction between Arsenic trioxide and Mefloquine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not use together; choose a non-QT-prolonging antimalarial for prophylaxis or treatment. If unavoidable, use intensive ECG and electrolyte monitoring.
What other medicines interact with Mefloquine?
MediHelp also lists interactions of Mefloquine with, for example, Dronedarone, Ibutilide, Levoketoconazole. The full list is on the Mefloquine page.
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