Tacrolimus and Neratinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Tacrolimus
Neratinib
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 exposure to P-gp substrate and risk of toxicity
Interaction Deep Dive
Concomitant use of neratinib with digoxin (a P-gp substrate with a narrow therapeutic index) significantly increased digoxin exposure in a clinical study, which may increase risk for associated toxicities. If coadministration of neratinib with a P-gp substrate with a narrow therapeutic index is needed, monitor for adverse reactions associated with the substrate2.
Why it happens (mechanism)
Inhibition of efflux transport of the P-gp substrate by neratinib
Literature reports
1 report — tap to read
a) In a clinical study in healthy subjects (n=18), coadministration of a single oral dose of digoxin 0.5 mg with steady-state neratinib 240 mg once daily increased the mean digoxin Cmax by 54% and AUC by 32% 1.
Common questions
Can I take Tacrolimus and Neratinib together?
Increased exposure to P-gp substrate and risk of toxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tacrolimus and Neratinib interaction?
It is rated major. Potentially serious — often needs a change or close 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 Neratinib 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 a safer alternative to one of these medications for me?
References (2)
Keep reading about Tacrolimus
Keep reading about Neratinib
These medications also interact with supplements
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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