Drug interactions
Calcium + Demeclocycline
Severity: Moderate
Calcium and Demeclocycline: 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 forms insoluble chelates with demeclocycline in the gut, reducing absorption of the antibiotic. This can lead to subtherapeutic levels and treatment failure.
What this interaction means in plain words
Calcium and Demeclocycline 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
Chelation of tetracycline by calcium in the gastrointestinal tract reducing absorption.
What to do
Give demeclocycline at least 2 hours before or several hours after oral calcium products. Dairy foods should be separated similarly.
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
- Calcium + Ceftriaxone Contraindicated
- Acalabrutinib + Calcium Moderate
- Alendronate + Calcium Moderate
- Atazanavir + Calcium Moderate
- Baloxavir marboxil + Calcium Moderate
- Bendroflumethiazide + Calcium Moderate
Frequently asked questions
Can I take Calcium with Demeclocycline?
MediHelp rates the interaction as moderate. Calcium and Demeclocycline 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 forms insoluble chelates with demeclocycline in the gut, reducing absorption of the antibiotic. This can lead to subtherapeutic levels and treatment failure.
How serious is the interaction between Calcium and Demeclocycline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Give demeclocycline at least 2 hours before or several hours after oral calcium products. Dairy foods should be separated similarly.
What other medicines interact with Calcium?
MediHelp also lists interactions of Calcium with, for example, Ceftriaxone, Acalabrutinib, Alendronate. The full list is on the Calcium page.
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