Drug interactions
Mefloquine + Metronidazole
Severity: Minor
Mefloquine and Metronidazole: minor 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
Mefloquine is metabolized by CYP3A4, and raised levels could increase neuropsychiatric effects and QT-related risks. Metronidazole is a weak inhibitor so the effect is likely modest and poorly documented.
What this interaction means in plain words
Mefloquine and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Mefloquine belongs to Anti Parasitic; Metronidazole belongs to Anti Parasitic.
Why it happens
Possible weak CYP3A4 inhibition by metronidazole reducing mefloquine clearance.
What to do
No dose change is generally required; counsel the patient to report dizziness, palpitations or neuropsychiatric symptoms.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
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 Metronidazole?
MediHelp rates the interaction as minor. Mefloquine and Metronidazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Mefloquine is metabolized by CYP3A4, and raised levels could increase neuropsychiatric effects and QT-related risks. Metronidazole is a weak inhibitor so the effect is likely modest and poorly documented.
How serious is the interaction between Mefloquine and Metronidazole?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is generally required; counsel the patient to report dizziness, palpitations or neuropsychiatric symptoms.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Pimozide, Amiodarone. The full list is on the Metronidazole page.
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