Nirmatrelvir Ritonavir and Simvastatin: Drug Interaction Guide

Quick answer: This is a major interaction — avoid combining Nirmatrelvir Ritonavir and Simvastatin unless specifically directed by your doctor.

Interaction severity: Major — avoid combination

How Nirmatrelvir Ritonavir interacts with Simvastatin

Ritonavir is a strong CYP3A4 inhibitor and markedly reduces simvastatin metabolism. Simvastatin concentrations can rise sharply, increasing risk of rhabdomyolysis.

What you should do

Withhold simvastatin before and during nirmatrelvir-ritonavir treatment and restart only after the recommended washout period. Use a non-CYP3A4 statin if lipid therapy cannot be interrupted.

Key facts

Severity

Major — avoid combination

Mechanism

Ritonavir is a strong CYP3A4 inhibitor and markedly reduces simvastatin metabolism. Simvastatin concentrations can rise ...

Action

Withhold simvastatin before and during nirmatrelvir-ritonavir treatment and restart only after the recommended washout p...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Nirmatrelvir Ritonavir and Simvastatin together?

No — this combination should generally be avoided. Withhold simvastatin before and during nirmatrelvir-ritonavir treatment and restart only after the recommended washout period. Use a non-CYP3A4 statin if lipid therapy cannot be interrupted.

What is the severity of this interaction?

The interaction between Nirmatrelvir Ritonavir and Simvastatin is classified as Major — avoid combination. Ritonavir is a strong CYP3A4 inhibitor and markedly reduces simvastatin metabolism. Simvastatin concentrations can rise sharply, increasing risk of rhabdomyolysis.

What should I do if I'm prescribed both?

Withhold simvastatin before and during nirmatrelvir-ritonavir treatment and restart only after the recommended washout period. Use a non-CYP3A4 statin if lipid therapy cannot be interrupted. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.