Drug interactions
Metronidazole + Tacrolimus
Severity: Moderate
Metronidazole and Tacrolimus: 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
Case reports describe increased tacrolimus concentrations after metronidazole is started, with a risk of nephrotoxicity and neurotoxicity. Because tacrolimus has a narrow therapeutic index, the interaction deserves attention.
What this interaction means in plain words
Metronidazole and Tacrolimus 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 belongs to Anti Parasitic; Tacrolimus belongs to Miscellaneous.
Why it happens
Metronidazole may inhibit CYP3A4-mediated tacrolimus metabolism.
What to do
Check tacrolimus trough levels and serum creatinine within a few days of starting or stopping metronidazole, and adjust the tacrolimus dose to target.
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
Other interactions of Tacrolimus
- Adenovirus types 4 and 7 live + Tacrolimus Contraindicated
- Bcg vaccine live + Tacrolimus Contraindicated
- Cidofovir + Tacrolimus Contraindicated
- Cyclosporin + Tacrolimus Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Tacrolimus Contraindicated
- Measles mumps and rubella vaccine live + Tacrolimus Contraindicated
Frequently asked questions
Can I take Metronidazole with Tacrolimus?
MediHelp rates the interaction as moderate. Metronidazole and Tacrolimus 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. Case reports describe increased tacrolimus concentrations after metronidazole is started, with a risk of nephrotoxicity and neurotoxicity. Because tacrolimus has a narrow therapeutic index, the interaction deserves attention.
How serious is the interaction between Metronidazole and Tacrolimus?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check tacrolimus trough levels and serum creatinine within a few days of starting or stopping metronidazole, and adjust the tacrolimus dose to target.
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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