Drug interactions
Larotrectinib + Tacrolimus
Severity: Moderate
Larotrectinib 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
Larotrectinib is a substrate and a weak inhibitor of CYP3A4 in vitro, so it may modestly increase tacrolimus concentrations. The clinical significance is not well characterized but tacrolimus has a narrow therapeutic index.
What this interaction means in plain words
Larotrectinib 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.
Larotrectinib belongs to Oncology; Tacrolimus belongs to Miscellaneous.
Why it happens
Possible CYP3A4 inhibition by larotrectinib reducing tacrolimus metabolism; clinical effect not firmly established.
What to do
Check tacrolimus trough levels within the first week or two of combined therapy and after any dose change. Adjust tacrolimus dose to target range.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Larotrectinib and Tacrolimus, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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
Other interactions of Larotrectinib
Frequently asked questions
Can I take Larotrectinib with Tacrolimus?
MediHelp rates the interaction as moderate. Larotrectinib 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. Larotrectinib is a substrate and a weak inhibitor of CYP3A4 in vitro, so it may modestly increase tacrolimus concentrations. The clinical significance is not well characterized but tacrolimus has a narrow therapeutic index.
How serious is the interaction between Larotrectinib 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 within the first week or two of combined therapy and after any dose change. Adjust tacrolimus dose to target range.
What other medicines interact with Tacrolimus?
MediHelp also lists interactions of Tacrolimus with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Cidofovir. The full list is on the Tacrolimus page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
