Drug interactions
Nirmatrelvir + Vincristine
Severity: Major
Nirmatrelvir and Vincristine: 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 inhibits CYP3A4 and is used with ritonavir, which also affects P-gp. Increased vincristine exposure can cause severe neurotoxicity, ileus and myelosuppression.
What this interaction means in plain words
Nirmatrelvir and Vincristine 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; Vincristine belongs to Oncology.
Why it happens
Inhibition of CYP3A4 reduces vincristine clearance.
What to do
Avoid the combination where possible, for example by delaying vincristine or choosing a non-interacting COVID-19 antiviral. If unavoidable, monitor closely for neurotoxicity and bowel obstruction.
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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Other interactions of Vincristine
- Adenovirus types 4 and 7 live + Vincristine Contraindicated
- Apalutamide + Vincristine Major
- Atazanavir + Vincristine Major
- Ceritinib + Vincristine Major
- Chloramphenicol + Vincristine Major
- Clarithromycin + Vincristine Major
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 Vincristine?
MediHelp rates the interaction as major. Nirmatrelvir and Vincristine 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 inhibits CYP3A4 and is used with ritonavir, which also affects P-gp. Increased vincristine exposure can cause severe neurotoxicity, ileus and myelosuppression.
How serious is the interaction between Nirmatrelvir and Vincristine?
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 the combination where possible, for example by delaying vincristine or choosing a non-interacting COVID-19 antiviral. If unavoidable, monitor closely for neurotoxicity and bowel obstruction.
What other medicines interact with Vincristine?
MediHelp also lists interactions of Vincristine with, for example, Adenovirus types 4 and 7 live, Apalutamide, Atazanavir. The full list is on the Vincristine page.
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