Drug interactions
Calcium carbonate + Gefitinib
Severity: Moderate
Calcium carbonate and Gefitinib: 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
Gefitinib needs an acidic stomach for adequate dissolution. Drugs that raise gastric pH, including antacids, can lower its absorption and potentially reduce antitumor effect.
What this interaction means in plain words
Calcium carbonate and Gefitinib 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; Gefitinib belongs to Oncology.
Why it happens
Elevated gastric pH reduces the solubility and absorption of gefitinib.
What to do
Take the antacid at least 6 hours before or after gefitinib. Monitor for loss of tumor response.
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 Gefitinib
Frequently asked questions
Can I take Calcium carbonate with Gefitinib?
MediHelp rates the interaction as moderate. Calcium carbonate and Gefitinib 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. Gefitinib needs an acidic stomach for adequate dissolution. Drugs that raise gastric pH, including antacids, can lower its absorption and potentially reduce antitumor effect.
How serious is the interaction between Calcium carbonate and Gefitinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Take the antacid at least 6 hours before or after gefitinib. Monitor for loss of tumor response.
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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