Drug interactions
Mefloquine + Verapamil
Severity: Moderate
Mefloquine and Verapamil: 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 slow cardiac conduction, and verapamil is a CYP3A4 and P-glycoprotein substrate and inhibitor while mefloquine is also metabolised by CYP3A4. Concurrent use may raise exposure to either drug and add to bradycardia, AV block or other conduction disturbances.
What this interaction means in plain words
Mefloquine and Verapamil 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; Verapamil belongs to Cardiovascular.
Why it happens
Additive effects on cardiac conduction combined with possible competition for CYP3A4 metabolism and P-glycoprotein transport.
What to do
Monitor heart rate, ECG and blood pressure when the combination is started, and watch for neuropsychiatric effects of mefloquine. Consider an alternative antimalarial if conduction abnormalities develop.
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Frequently asked questions
Can I take Mefloquine with Verapamil?
MediHelp rates the interaction as moderate. Mefloquine and Verapamil 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 slow cardiac conduction, and verapamil is a CYP3A4 and P-glycoprotein substrate and inhibitor while mefloquine is also metabolised by CYP3A4. Concurrent use may raise exposure to either drug and add to bradycardia, AV block or other conduction disturbances.
How serious is the interaction between Mefloquine and Verapamil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate, ECG and blood pressure when the combination is started, and watch for neuropsychiatric effects of mefloquine. Consider an alternative antimalarial if conduction abnormalities develop.
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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