Drug interactions
Carbamazepine + Quinidine
Severity: Major
Carbamazepine and Quinidine: 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
Carbamazepine induces CYP3A4 and markedly lowers quinidine concentrations, which can lead to loss of antiarrhythmic or antimalarial effect. Stopping carbamazepine later may cause quinidine levels to rise and cause toxicity.
What this interaction means in plain words
Carbamazepine and Quinidine 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.
Carbamazepine belongs to Central Nervous System; Quinidine belongs to Anti Parasitic.
Why it happens
Carbamazepine induces CYP3A4, increasing the metabolism of quinidine.
What to do
Avoid the combination if possible. If used together, monitor quinidine levels and ECG, adjust the dose, and reassess if carbamazepine is started or stopped.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Quinidine?
MediHelp rates the interaction as major. Carbamazepine and Quinidine 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. Carbamazepine induces CYP3A4 and markedly lowers quinidine concentrations, which can lead to loss of antiarrhythmic or antimalarial effect. Stopping carbamazepine later may cause quinidine levels to rise and cause toxicity.
How serious is the interaction between Carbamazepine and Quinidine?
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 if possible. If used together, monitor quinidine levels and ECG, adjust the dose, and reassess if carbamazepine is started or stopped.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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