Drug interactions
Calcium carbonate + Estramustine
Severity: Moderate
Calcium carbonate and Estramustine: 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
Estramustine contains an estradiol-nitrogen mustard conjugate with phosphate, and its absorption is reduced by calcium-containing products and milk. Calcium carbonate may therefore lower its exposure and reduce efficacy.
What this interaction means in plain words
Calcium carbonate and Estramustine 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
Calcium forms insoluble complexes with estramustine phosphate in the gut, decreasing its absorption.
What to do
Separate doses by at least 2 hours, and take estramustine on an empty stomach with water. Avoid taking it together with calcium-containing products.
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
Frequently asked questions
Can I take Calcium carbonate with Estramustine?
MediHelp rates the interaction as moderate. Calcium carbonate and Estramustine 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. Estramustine contains an estradiol-nitrogen mustard conjugate with phosphate, and its absorption is reduced by calcium-containing products and milk. Calcium carbonate may therefore lower its exposure and reduce efficacy.
How serious is the interaction between Calcium carbonate and Estramustine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Separate doses by at least 2 hours, and take estramustine on an empty stomach with water. Avoid taking it together with calcium-containing products.
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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