Drug interactions
Buprenorphine long-acting + Metronidazole
Severity: Moderate
Buprenorphine long-acting 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
Metronidazole may modestly increase buprenorphine levels through CYP3A4 inhibition. With a long-acting injection, the dose cannot be quickly reduced, so excess opioid effects may persist.
What this interaction means in plain words
Buprenorphine long-acting 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.
Why it happens
CYP3A4 inhibition by metronidazole may reduce buprenorphine metabolism.
What to do
Monitor for sedation, respiratory depression and opioid toxicity during concurrent therapy. If toxicity develops, consider switching to a buprenorphine formulation that allows dose adjustment.
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 Buprenorphine long-acting with Metronidazole?
MediHelp rates the interaction as moderate. Buprenorphine long-acting 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. Metronidazole may modestly increase buprenorphine levels through CYP3A4 inhibition. With a long-acting injection, the dose cannot be quickly reduced, so excess opioid effects may persist.
How serious is the interaction between Buprenorphine long-acting 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: Monitor for sedation, respiratory depression and opioid toxicity during concurrent therapy. If toxicity develops, consider switching to a buprenorphine formulation that allows dose adjustment.
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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