Nirmatrelvir Ritonavir and Tacrolimus: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Nirmatrelvir Ritonavir and Tacrolimus unless specifically directed by your doctor.
How Nirmatrelvir Ritonavir interacts with Tacrolimus
Ritonavir is a potent CYP3A4 and P-glycoprotein inhibitor, and tacrolimus is highly dependent on CYP3A4 clearance. Tacrolimus concentrations can rise rapidly to toxic levels.
What you should do
Avoid unless specialist therapeutic drug monitoring is available. Hold or drastically adjust tacrolimus with frequent levels and renal monitoring.
Key facts
Severity
Major — avoid combination
Mechanism
Ritonavir is a potent CYP3A4 and P-glycoprotein inhibitor, and tacrolimus is highly dependent on CYP3A4 clearance. Tacro...
Action
Avoid unless specialist therapeutic drug monitoring is available. Hold or drastically adjust tacrolimus with frequent le...
Frequently asked questions
Can I take Nirmatrelvir Ritonavir and Tacrolimus together?
No — this combination should generally be avoided. Avoid unless specialist therapeutic drug monitoring is available. Hold or drastically adjust tacrolimus with frequent levels and renal monitoring.
What is the severity of this interaction?
The interaction between Nirmatrelvir Ritonavir and Tacrolimus is classified as Major — avoid combination. Ritonavir is a potent CYP3A4 and P-glycoprotein inhibitor, and tacrolimus is highly dependent on CYP3A4 clearance. Tacrolimus concentrations can rise rapidly to toxic levels.
What should I do if I'm prescribed both?
Avoid unless specialist therapeutic drug monitoring is available. Hold or drastically adjust tacrolimus with frequent levels and renal monitoring. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.