Tacrolimus and Ertapenem Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tacrolimus
Ertapenem Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased tacrolimus plasma concentrations
Interaction Deep Dive
Caution is advised when using ertapenem together with tacrolimus as this may result in the inhibition of tacrolimus metabolism and lower tacrolimus doses may required to achieve therapeutic concentrations. In a retrospective evaluation of 13 renal transplant patients, the concomitant administration of IV ertapenem and tacrolimus significantly decreased the mean tacrolimus dose required to maintain therapeutic concentrations, from 0.079 mg/kg to 0.043 mg/kg, 2 days following the initiation of ertapenem. If concomitant use is required, monitor tacrolimus concentrations and reduce dose as clinically indicated1.
Why it happens (mechanism)
Unknown
Literature reports
1 report — tap to read
a) In a retrospective evaluation of 13 renal transplant patients (mean age, 34.8 years) on a stabilized tacrolimus regimen, concomitant administration of IV ertapenem 500 mg once daily resulted in a significant decrease in the mean tacrolimus dose required to maintain therapeutic concentrations. Two days following the initiation of IV ertapenem, mean tacrolimus doses decreased significantly from 0.079 mg/kg to 0.043 mg/kg (p less than 0.005) 1.
Common questions
Can I take Tacrolimus and Ertapenem Injection together?
Increased tacrolimus plasma concentrations Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tacrolimus and Ertapenem Injection interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Tacrolimus or Ertapenem Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Bora F, Aliosmanoglu I, Kocak H, et al: Drug interaction between tacrolimus and ertapenem in renal transplantation recipients. Transplant Proc 2012; 44(10):3029-3032. PubMed
Keep reading about Tacrolimus
Keep reading about Ertapenem Injection
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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