Drug interactions
Metronidazole + Propylene glycol
Severity: Moderate
Metronidazole and Propylene glycol: 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
Propylene glycol is a vehicle in some oral and injectable formulations, and a disulfiram-like reaction with metronidazole has been described in the setting of large exposures. Flushing, nausea, vomiting and tachycardia may occur, though evidence is limited.
What this interaction means in plain words
Metronidazole and Propylene glycol 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
Proposed inhibition of aldehyde dehydrogenase similar to the metronidazole-alcohol reaction; not firmly established.
What to do
Avoid propylene glycol-containing products in patients receiving metronidazole and for at least a few days after stopping, especially with large doses.
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 Metronidazole
- Ethanol + Metronidazole Contraindicated
- Metronidazole + Pimozide Contraindicated
- Amiodarone + Metronidazole Major
- Disulfiram + Metronidazole Major
- Ergotamine + Metronidazole Major
- Lomitapide + Metronidazole Major
Frequently asked questions
Can I take Metronidazole with Propylene glycol?
MediHelp rates the interaction as moderate. Metronidazole and Propylene glycol 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. Propylene glycol is a vehicle in some oral and injectable formulations, and a disulfiram-like reaction with metronidazole has been described in the setting of large exposures. Flushing, nausea, vomiting and tachycardia may occur, though evidence is limited.
How serious is the interaction between Metronidazole and Propylene glycol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid propylene glycol-containing products in patients receiving metronidazole and for at least a few days after stopping, especially with large doses.
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.
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