Drug interactions
Calcium carbonate + Nitrofurantoin
Severity: Moderate
Calcium carbonate and Nitrofurantoin: 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
Antacids containing calcium or magnesium may reduce nitrofurantoin absorption, as shown mainly with magnesium trisilicate. This could lower urinary concentrations and reduce efficacy in urinary tract infection.
What this interaction means in plain words
Calcium carbonate and Nitrofurantoin 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; Nitrofurantoin belongs to Anti Bacterial.
Why it happens
Adsorption or binding of nitrofurantoin in the gut, and possibly altered gastric pH, reduce its absorption.
What to do
Avoid taking calcium carbonate antacids with nitrofurantoin; separate by at least 2 hours. Watch for lack of clinical response in the infection.
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 Nitrofurantoin
- Nitrofurantoin + Pexidartinib Major
- Nitrofurantoin + Pretomanid Major
- Aluminum hydroxide + Nitrofurantoin Moderate
- Bupivacaine implant + Nitrofurantoin Moderate
- Cholera vaccine + Nitrofurantoin Moderate
- Dapsone + Nitrofurantoin Moderate
Frequently asked questions
Can I take Calcium carbonate with Nitrofurantoin?
MediHelp rates the interaction as moderate. Calcium carbonate and Nitrofurantoin 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. Antacids containing calcium or magnesium may reduce nitrofurantoin absorption, as shown mainly with magnesium trisilicate. This could lower urinary concentrations and reduce efficacy in urinary tract infection.
How serious is the interaction between Calcium carbonate and Nitrofurantoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid taking calcium carbonate antacids with nitrofurantoin; separate by at least 2 hours. Watch for lack of clinical response in the infection.
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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