Drug interactions
Calcium carbonate + Quinidine
Severity: Moderate
Calcium carbonate and Quinidine: 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
Calcium carbonate can alkalinize urine, reducing renal excretion of quinidine and raising its levels. Higher concentrations may prolong QT and cause arrhythmias.
What this interaction means in plain words
Calcium carbonate and Quinidine 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.
Calcium carbonate belongs to Gastrointestinal Tract; Quinidine belongs to Anti Parasitic.
Why it happens
Urinary alkalinization increases tubular reabsorption of the weakly basic quinidine, reducing its clearance.
What to do
Monitor ECG (QT interval) and quinidine concentrations when starting or stopping regular antacid use. Reduce quinidine dose if levels rise.
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 Calcium carbonate
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 Calcium carbonate with Quinidine?
MediHelp rates the interaction as moderate. Calcium carbonate and Quinidine 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. Calcium carbonate can alkalinize urine, reducing renal excretion of quinidine and raising its levels. Higher concentrations may prolong QT and cause arrhythmias.
How serious is the interaction between Calcium carbonate and Quinidine?
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 (QT interval) and quinidine concentrations when starting or stopping regular antacid use. Reduce quinidine dose if levels rise.
What other medicines interact with Calcium carbonate?
MediHelp also lists interactions of Calcium carbonate with, for example, Acalabrutinib, Alendronate, Amlodipine-hydrochlorothiazide-valsartan. The full list is on the Calcium carbonate page.
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