Drug interactions
Quinidine + Sodium citrate / citric acid
Severity: Moderate
Quinidine and Sodium citrate / citric acid: 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
Citrate is metabolized to bicarbonate and raises urinary pH, which decreases the renal excretion of quinidine. Higher quinidine levels can lead to conduction disturbances and arrhythmias.
What this interaction means in plain words
Quinidine and Sodium citrate / citric acid 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.
Why it happens
Urinary alkalinization increases passive tubular reabsorption of quinidine and reduces its renal clearance.
What to do
Monitor ECG and quinidine concentrations when citrate-containing alkalinizers are used regularly. Lower the quinidine dose if levels rise or QRS or QT widening appears.
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?
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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 Sodium citrate / citric acid?
MediHelp rates the interaction as moderate. Quinidine and Sodium citrate / citric acid 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. Citrate is metabolized to bicarbonate and raises urinary pH, which decreases the renal excretion of quinidine. Higher quinidine levels can lead to conduction disturbances and arrhythmias.
How serious is the interaction between Quinidine and Sodium citrate / citric acid?
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 ECG and quinidine concentrations when citrate-containing alkalinizers are used regularly. Lower the quinidine dose if levels rise or QRS or QT widening appears.
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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