Drug interactions
Cholestyramine + Metronidazole
Severity: Moderate
Cholestyramine and Metronidazole: 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
Cholestyramine, an anion-exchange resin, can bind oral metronidazole in the gut and reduce its absorption. This may lower metronidazole concentrations and weaken antimicrobial effect.
What this interaction means in plain words
Cholestyramine and Metronidazole 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.
Cholestyramine belongs to Cardiovascular; Metronidazole belongs to Anti Parasitic.
Why it happens
Cholestyramine binds metronidazole in the gastrointestinal tract, decreasing its absorption.
What to do
Give oral metronidazole at least 1 hour before or 4 to 6 hours after cholestyramine. Monitor clinical response.
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 Cholestyramine and Metronidazole, 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 Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Other interactions of Cholestyramine
Frequently asked questions
Can I take Cholestyramine with Metronidazole?
MediHelp rates the interaction as moderate. Cholestyramine and Metronidazole 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. Cholestyramine, an anion-exchange resin, can bind oral metronidazole in the gut and reduce its absorption. This may lower metronidazole concentrations and weaken antimicrobial effect.
How serious is the interaction between Cholestyramine and Metronidazole?
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 oral metronidazole at least 1 hour before or 4 to 6 hours after cholestyramine. Monitor clinical response.
What other medicines interact with Metronidazole?
MediHelp also lists interactions of Metronidazole with, for example, Ethanol, Pimozide, Amiodarone. The full list is on the Metronidazole 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.
