Drug interactions
Calcium citrate + Doxycycline
Severity: Moderate
Calcium citrate and Doxycycline: 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 citrate supplements can bind doxycycline in the gut, reducing its absorption and potentially compromising antibacterial efficacy.
What this interaction means in plain words
Calcium citrate and Doxycycline 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 doxycycline by calcium cations in the gastrointestinal tract reduces absorption.
What to do
Take doxycycline at least 2 hours before or 4 hours after calcium citrate. Monitor clinical response to the antibiotic.
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 Doxycycline
- Acitretin + Doxycycline Contraindicated
- Aminolevulinic acid + Doxycycline Major
- Cholera vaccine + Doxycycline Major
- Doxycycline + Isotretinoin Major
- Doxycycline + Methoxyflurane Major
- Doxycycline + Microbiota Major
Frequently asked questions
Can I take Calcium citrate with Doxycycline?
MediHelp rates the interaction as moderate. Calcium citrate and Doxycycline 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 citrate supplements can bind doxycycline in the gut, reducing its absorption and potentially compromising antibacterial efficacy.
How serious is the interaction between Calcium citrate and Doxycycline?
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 doxycycline at least 2 hours before or 4 hours after calcium citrate. Monitor clinical response to the antibiotic.
What other medicines interact with Doxycycline?
MediHelp also lists interactions of Doxycycline with, for example, Acitretin, Aminolevulinic acid, Cholera vaccine. The full list is on the Doxycycline page.
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