Drug interactions
Nirmatrelvir / ritonavir + Simvastatin
Severity: Contraindicated
Nirmatrelvir / ritonavir and Simvastatin: contraindicated 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
Ritonavir-boosted nirmatrelvir strongly inhibits CYP3A and substantially increases simvastatin concentrations, which can cause myopathy and rhabdomyolysis. The combination is contraindicated.
What this interaction means in plain words
Nirmatrelvir / ritonavir and Simvastatin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Ritonavir and nirmatrelvir inhibit CYP3A4, blocking simvastatin metabolism.
What to do
Stop simvastatin before starting the antiviral, keep it stopped during the 5-day course, and resume about 5 days after completion; a short statin pause is generally acceptable.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Simvastatin
- Atazanavir + Simvastatin Contraindicated
- Clarithromycin + Simvastatin Contraindicated
- Cobicistat + Simvastatin Contraindicated
- Cyclosporine + Simvastatin Contraindicated
- Cyclosporin + Simvastatin Contraindicated
- Danazol + Simvastatin Contraindicated
Frequently asked questions
Can I take Nirmatrelvir / ritonavir with Simvastatin?
MediHelp rates the interaction as contraindicated. Nirmatrelvir / ritonavir and Simvastatin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Ritonavir-boosted nirmatrelvir strongly inhibits CYP3A and substantially increases simvastatin concentrations, which can cause myopathy and rhabdomyolysis. The combination is contraindicated.
How serious is the interaction between Nirmatrelvir / ritonavir and Simvastatin?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Stop simvastatin before starting the antiviral, keep it stopped during the 5-day course, and resume about 5 days after completion; a short statin pause is generally acceptable.
What other medicines interact with Simvastatin?
MediHelp also lists interactions of Simvastatin with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Simvastatin page.
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