Drug interactions
Mefloquine + Mifepristone
Severity: Major
Mefloquine and Mifepristone: 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
Mifepristone can prolong the QT interval and is a CYP3A4 inhibitor, which may raise mefloquine concentrations. This combines a pharmacodynamic and a pharmacokinetic effect and increases the risk of QT-related arrhythmia and mefloquine toxicity.
What this interaction means in plain words
Mefloquine and Mifepristone 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; Mifepristone belongs to Endocrine.
Why it happens
Additive QT prolongation plus inhibition of CYP3A4-mediated mefloquine metabolism by mifepristone.
What to do
Avoid the combination when possible and use an alternative antimalarial. If both are required, obtain an ECG and monitor for mefloquine adverse effects.
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 Mifepristone
- Apixaban + Mifepristone Contraindicated
- Argatroban + Mifepristone Contraindicated
- Cisapride + Mifepristone Contraindicated
- Cortisone + Mifepristone Contraindicated
- Cyclosporin + Mifepristone Contraindicated
- Dabigatran etexilate + Mifepristone Contraindicated
Frequently asked questions
Can I take Mefloquine with Mifepristone?
MediHelp rates the interaction as major. Mefloquine and Mifepristone 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. Mifepristone can prolong the QT interval and is a CYP3A4 inhibitor, which may raise mefloquine concentrations. This combines a pharmacodynamic and a pharmacokinetic effect and increases the risk of QT-related arrhythmia and mefloquine toxicity.
How serious is the interaction between Mefloquine and Mifepristone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination when possible and use an alternative antimalarial. If both are required, obtain an ECG and monitor for mefloquine adverse effects.
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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