Drug interactions
Clarithromycin + Quinine
Severity: Major
Clarithromycin and Quinine: major interaction.
Last updated Sources: Health Canada product monograph
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
Clarithromycin may raise quinine levels and both drugs prolong the QT interval, increasing the risk of serious ventricular arrhythmias. Cinchonism may also be more likely with higher quinine exposure.
What this interaction means in plain words
Clarithromycin and Quinine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clarithromycin belongs to Anti Bacterial; Quinine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation, plus CYP3A4 inhibition by clarithromycin decreasing quinine clearance.
What to do
Avoid the combination where possible and use a non-interacting antibiotic. If necessary, check ECG and electrolytes and monitor for arrhythmia and cinchonism.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
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 Clarithromycin with Quinine?
MediHelp rates the interaction as major. Clarithromycin and Quinine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Clarithromycin may raise quinine levels and both drugs prolong the QT interval, increasing the risk of serious ventricular arrhythmias. Cinchonism may also be more likely with higher quinine exposure.
How serious is the interaction between Clarithromycin and Quinine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use a non-interacting antibiotic. If necessary, check ECG and electrolytes and monitor for arrhythmia and cinchonism.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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