Drug interactions
Cimetidine + Mefloquine
Severity: Minor
Cimetidine 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
Cimetidine may modestly raise mefloquine concentrations. This could increase neuropsychiatric and gastrointestinal adverse effects.
What this interaction means in plain words
Cimetidine 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.
Cimetidine belongs to Gastrointestinal Tract; Mefloquine belongs to Anti Parasitic.
Why it happens
Cimetidine inhibits CYP3A4-mediated metabolism of mefloquine.
What to do
Monitor for dizziness, neuropsychiatric symptoms and other mefloquine adverse effects; use an alternative acid suppressant if problems arise.
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 Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram 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 Cimetidine with Mefloquine?
MediHelp rates the interaction as minor. Cimetidine 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. Cimetidine may modestly raise mefloquine concentrations. This could increase neuropsychiatric and gastrointestinal adverse effects.
How serious is the interaction between Cimetidine 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: Monitor for dizziness, neuropsychiatric symptoms and other mefloquine adverse effects; use an alternative acid suppressant if problems arise.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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