Drug interactions
Nirmatrelvir + Tacrolimus
Severity: Major
Nirmatrelvir and Tacrolimus: major 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
Nirmatrelvir is a potent CYP3A inhibitor and is only given with ritonavir. Tacrolimus has a narrow therapeutic index and blood levels can rise sharply within the first days of co-treatment. This can cause nephrotoxicity, neurotoxicity and QT prolongation.
What this interaction means in plain words
Nirmatrelvir and Tacrolimus can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Nirmatrelvir belongs to Anti Virals; Tacrolimus belongs to Miscellaneous.
Why it happens
Strong inhibition of CYP3A4 (and P-glycoprotein) reduces the intestinal and hepatic clearance of tacrolimus.
What to do
Avoid if possible and consider an alternative COVID-19 antiviral. If it must be used, stop or sharply reduce tacrolimus per transplant team guidance, monitor trough levels, renal function and ECG, and re-titrate after the antiviral course ends.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Nirmatrelvir 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 7 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 Nirmatrelvir
- Alfuzosin + Nirmatrelvir Contraindicated
- Amiodarone + Nirmatrelvir Contraindicated
- Apalutamide + Nirmatrelvir Contraindicated
- Carbamazepine + Nirmatrelvir Contraindicated
- Colchicine + Nirmatrelvir Contraindicated
- Dronedarone + Nirmatrelvir Contraindicated
Frequently asked questions
Can I take Nirmatrelvir with Tacrolimus?
MediHelp rates the interaction as major. Nirmatrelvir and Tacrolimus can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Nirmatrelvir is a potent CYP3A inhibitor and is only given with ritonavir. Tacrolimus has a narrow therapeutic index and blood levels can rise sharply within the first days of co-treatment. This can cause nephrotoxicity, neurotoxicity and QT prolongation.
How serious is the interaction between Nirmatrelvir and Tacrolimus?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible and consider an alternative COVID-19 antiviral. If it must be used, stop or sharply reduce tacrolimus per transplant team guidance, monitor trough levels, renal function and ECG, and re-titrate after the antiviral course ends.
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.
