Drug interactions
Bismuth subsalicylate + Oxytetracycline
Severity: Moderate
Bismuth subsalicylate and Oxytetracycline: 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 in oral bismuth subsalicylate can bind oxytetracycline in the gut and reduce its absorption. This may lead to lower antibiotic levels and treatment failure.
What this interaction means in plain words
Bismuth subsalicylate and Oxytetracycline 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 subsalicylate belongs to Gastrointestinal Tract; Oxytetracycline belongs to Anti Bacterial.
Why it happens
Chelation of oxytetracycline by bismuth in the gastrointestinal tract reduces absorption.
What to do
Separate doses by at least 2 to 3 hours, giving oxytetracycline first, or use an alternative if separation is not 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 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
Other interactions of Oxytetracycline
- Isotretinoin + Oxytetracycline Contraindicated
- Aluminum hydroxide + Oxytetracycline Moderate
- Ampicillin-sulbactam + Oxytetracycline Moderate
- Ampicillin + Oxytetracycline Moderate
- Atracurium + Oxytetracycline Moderate
- Calcium carbonate + Oxytetracycline Moderate
Frequently asked questions
Can I take Bismuth subsalicylate with Oxytetracycline?
MediHelp rates the interaction as moderate. Bismuth subsalicylate and Oxytetracycline 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 in oral bismuth subsalicylate can bind oxytetracycline in the gut and reduce its absorption. This may lead to lower antibiotic levels and treatment failure.
How serious is the interaction between Bismuth subsalicylate and Oxytetracycline?
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 by at least 2 to 3 hours, giving oxytetracycline first, or use an alternative if separation is not feasible.
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.
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