Drug interactions
Cimetidine + Quinine
Severity: Moderate
Cimetidine and Quinine: 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
Cimetidine reduces quinine clearance and increases its exposure. Higher quinine levels may increase cinchonism and potentially QT-related risk.
What this interaction means in plain words
Cimetidine and Quinine 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.
Cimetidine belongs to Gastrointestinal Tract; Quinine belongs to Anti Parasitic.
Why it happens
Cimetidine inhibits CYP3A4-mediated metabolism of quinine and competes for renal tubular cationic secretion.
What to do
Monitor for tinnitus, hypoglycemia and QT prolongation, particularly in severe malaria or with other QT-prolonging drugs. Consider an alternative acid suppressant such as famotidine.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cimetidine and Quinine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
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 Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine Contraindicated
Frequently asked questions
Can I take Cimetidine with Quinine?
MediHelp rates the interaction as moderate. Cimetidine and Quinine 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. Cimetidine reduces quinine clearance and increases its exposure. Higher quinine levels may increase cinchonism and potentially QT-related risk.
How serious is the interaction between Cimetidine and Quinine?
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 for tinnitus, hypoglycemia and QT prolongation, particularly in severe malaria or with other QT-prolonging drugs. Consider an alternative acid suppressant such as famotidine.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
