Drug interactions
Quinidine + Quinine
Severity: Contraindicated
Quinidine and Quinine: contraindicated 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
Quinine and quinidine are stereoisomers with similar cardiac effects, and their combination markedly increases QT prolongation and arrhythmia risk. Both also compete for elimination and can raise each other's levels, and cinchonism is more likely.
What this interaction means in plain words
Quinidine and Quinine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Quinidine belongs to Anti Parasitic; Quinine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation and class Ia effects, with competition for renal tubular secretion and CYP-mediated clearance.
What to do
Do not co-administer; for severe malaria, use a single cinchona alkaloid or an alternative such as artesunate, and separate parenteral quinidine and quinine use with ECG monitoring if sequential.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine Contraindicated
Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Quinidine with Quinine?
MediHelp rates the interaction as contraindicated. Quinidine and Quinine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Quinine and quinidine are stereoisomers with similar cardiac effects, and their combination markedly increases QT prolongation and arrhythmia risk. Both also compete for elimination and can raise each other's levels, and cinchonism is more likely.
How serious is the interaction between Quinidine and Quinine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer; for severe malaria, use a single cinchona alkaloid or an alternative such as artesunate, and separate parenteral quinidine and quinine use with ECG monitoring if sequential.
What other medicines interact with Quinine?
MediHelp also lists interactions of Quinine with, for example, Arsenic trioxide, Dofetilide, Dronedarone. The full list is on the Quinine page.
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