Drug interactions
Apixaban + Nirmatrelvir / ritonavir
Severity: Major
Apixaban and Nirmatrelvir / ritonavir: major interaction.
Last updated Sources: US FDA label
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 is a strong CYP3A4 and P-gp inhibitor and increases apixaban exposure during the course of treatment. This raises bleeding risk.
What this interaction means in plain words
Apixaban and Nirmatrelvir / ritonavir 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.
Why it happens
Ritonavir inhibits CYP3A4 and P-gp, reducing apixaban metabolism and efflux.
What to do
Consider an alternative COVID-19 therapy. If co-prescribed, reduce apixaban from 5 mg to 2.5 mg twice daily, or hold or avoid it at the 2.5 mg dose, and monitor for bleeding.
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?
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References
Other interactions of Apixaban
- Apixaban + Dabigatran Contraindicated
- Apixaban + Defibrotide Contraindicated
- Apixaban + Edoxaban Contraindicated
- Apixaban + Ketorolac Contraindicated
- Apixaban + Mifepristone Contraindicated
- Abciximab + Apixaban Major
Frequently asked questions
Can I take Apixaban with Nirmatrelvir / ritonavir?
MediHelp rates the interaction as major. Apixaban and Nirmatrelvir / ritonavir 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. Ritonavir is a strong CYP3A4 and P-gp inhibitor and increases apixaban exposure during the course of treatment. This raises bleeding risk.
How serious is the interaction between Apixaban and Nirmatrelvir / ritonavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider an alternative COVID-19 therapy. If co-prescribed, reduce apixaban from 5 mg to 2.5 mg twice daily, or hold or avoid it at the 2.5 mg dose, and monitor for bleeding.
What other medicines interact with Apixaban?
MediHelp also lists interactions of Apixaban with, for example, Dabigatran, Defibrotide, Edoxaban. The full list is on the Apixaban page.
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