Drug interactions
Mefloquine + Voriconazole
Severity: Major
Mefloquine and Voriconazole: 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
Voriconazole may increase mefloquine concentrations, and both drugs can prolong the QT interval. This raises the risk of arrhythmia and neuropsychiatric toxicity, and mefloquine's long half-life extends the period of risk.
What this interaction means in plain words
Mefloquine and Voriconazole 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; Voriconazole belongs to Anti Fungals.
Why it happens
Voriconazole inhibits CYP3A4 metabolism of mefloquine, with additive QT prolongation.
What to do
Avoid the combination during and for several weeks after mefloquine; choose another antimalarial or antifungal, and monitor ECG if unavoidable.
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 Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole 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 Voriconazole?
MediHelp rates the interaction as major. Mefloquine and Voriconazole 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. Voriconazole may increase mefloquine concentrations, and both drugs can prolong the QT interval. This raises the risk of arrhythmia and neuropsychiatric toxicity, and mefloquine's long half-life extends the period of risk.
How serious is the interaction between Mefloquine and Voriconazole?
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 during and for several weeks after mefloquine; choose another antimalarial or antifungal, and monitor ECG if unavoidable.
What other medicines interact with Voriconazole?
MediHelp also lists interactions of Voriconazole with, for example, Avanafil, Butabarbital, Carbamazepine. The full list is on the Voriconazole page.
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