Drug interactions
Grapefruit + Mefloquine
Severity: Minor
Grapefruit and Mefloquine: 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
Grapefruit juice inhibits intestinal CYP3A4 and may modestly raise mefloquine levels. Clinical impact is uncertain but could add to dose-related adverse effects.
What this interaction means in plain words
Grapefruit and Mefloquine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Inhibition of intestinal CYP3A4 reduces mefloquine first-pass metabolism.
What to do
Advise avoiding large amounts of grapefruit juice during mefloquine therapy. Report dizziness 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 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 Grapefruit with Mefloquine?
MediHelp rates the interaction as minor. Grapefruit and Mefloquine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Grapefruit juice inhibits intestinal CYP3A4 and may modestly raise mefloquine levels. Clinical impact is uncertain but could add to dose-related adverse effects.
How serious is the interaction between Grapefruit and Mefloquine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise avoiding large amounts of grapefruit juice during mefloquine therapy. Report dizziness or neuropsychiatric symptoms.
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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