Drug interactions
Bismuth subsalicylate + Demeclocycline
Severity: Moderate
Bismuth subsalicylate 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
Bismuth salts bind tetracyclines in the gut and can reduce demeclocycline absorption. This may lead to subtherapeutic antibiotic levels and treatment failure.
What this interaction means in plain words
Bismuth subsalicylate 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 demeclocycline by bismuth in the gastrointestinal tract reduces its oral absorption.
What to do
Separate administration by at least 2 to 3 hours, giving demeclocycline first. Avoid bismuth during short courses of tetracycline if 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 Bismuth subsalicylate and Demeclocycline, 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 7 days on the web. No card needed.
Other interactions of Bismuth subsalicylate
- Bismuth subsalicylate + Dichlorphenamide Major
- Bismuth subsalicylate + Warfarin Major
- Acetylsalicylic acid + Bismuth subsalicylate Moderate
- Amlodipine-benazepril + Bismuth subsalicylate Moderate
- Aspirin / citric acid / sodium bicarbonate + Bismuth subsalicylate Moderate
- Aspirin rectal + Bismuth subsalicylate Moderate
Frequently asked questions
Can I take Bismuth subsalicylate with Demeclocycline?
MediHelp rates the interaction as moderate. Bismuth subsalicylate 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. Bismuth salts bind tetracyclines in the gut and can reduce demeclocycline absorption. This may lead to subtherapeutic antibiotic levels and treatment failure.
How serious is the interaction between Bismuth subsalicylate 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: Separate administration by at least 2 to 3 hours, giving demeclocycline first. Avoid bismuth during short courses of tetracycline if possible.
What other medicines interact with Bismuth subsalicylate?
MediHelp also lists interactions of Bismuth subsalicylate with, for example, Dichlorphenamide, Warfarin, Acetylsalicylic acid. The full list is on the Bismuth subsalicylate 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.
