Drug interactions
Demeclocycline + Magnesium hydroxide
Severity: Moderate
Demeclocycline and Magnesium hydroxide: 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
Magnesium forms insoluble chelates with tetracyclines such as demeclocycline in the gut, markedly reducing absorption. This can lead to subtherapeutic antibiotic levels and treatment failure.
What this interaction means in plain words
Demeclocycline and Magnesium hydroxide 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 demeclocycline by magnesium in the gastrointestinal tract, with a rise in gastric pH, reduces absorption.
What to do
Separate doses so demeclocycline is taken at least 2 hours before or 4 hours after magnesium products. Use an alternative to the antacid when feasible.
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 Magnesium hydroxide
Frequently asked questions
Can I take Demeclocycline with Magnesium hydroxide?
MediHelp rates the interaction as moderate. Demeclocycline and Magnesium hydroxide 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. Magnesium forms insoluble chelates with tetracyclines such as demeclocycline in the gut, markedly reducing absorption. This can lead to subtherapeutic antibiotic levels and treatment failure.
How serious is the interaction between Demeclocycline and Magnesium hydroxide?
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 so demeclocycline is taken at least 2 hours before or 4 hours after magnesium products. Use an alternative to the antacid when feasible.
What other medicines interact with Magnesium hydroxide?
MediHelp also lists interactions of Magnesium hydroxide with, for example, Ciprofloxacin, Dolutegravir, Gemifloxacin. The full list is on the Magnesium hydroxide page.
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