Drug interactions
Magnesium hydroxide + Tetracycline
Severity: Moderate
Magnesium hydroxide and Tetracycline: 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-containing antacids form insoluble chelates with oral tetracycline, substantially reducing its absorption. This can lead to subtherapeutic levels and antibiotic treatment failure.
What this interaction means in plain words
Magnesium hydroxide and Tetracycline 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 hydroxide belongs to Gastrointestinal Tract; Tetracycline belongs to Anti Bacterial.
Why it happens
Chelation of tetracycline by divalent magnesium cations in the gut reduces absorption.
What to do
Give tetracycline at least 2 hours before or 4 hours after magnesium hydroxide. Avoid regular antacid use during the course when possible.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Magnesium hydroxide and Tetracycline, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Magnesium hydroxide
Other interactions of Tetracycline
- Acitretin + Tetracycline Contraindicated
- Methoxyflurane + Tetracycline Contraindicated
- Isotretinoin + Tetracycline Major
- Palovarotene + Tetracycline Major
- Strontium ranelate + Tetracycline Major
- Tetracycline + Tretinoin Major
Frequently asked questions
Can I take Magnesium hydroxide with Tetracycline?
MediHelp rates the interaction as moderate. Magnesium hydroxide and Tetracycline 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-containing antacids form insoluble chelates with oral tetracycline, substantially reducing its absorption. This can lead to subtherapeutic levels and antibiotic treatment failure.
How serious is the interaction between Magnesium hydroxide and Tetracycline?
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 tetracycline at least 2 hours before or 4 hours after magnesium hydroxide. Avoid regular antacid use during the course when possible.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
