Drug interactions
Nirmatrelvir + Vinblastine
Severity: Major
Nirmatrelvir and Vinblastine: 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 is given with ritonavir, a strong CYP3A4 and P-glycoprotein inhibitor, which can markedly raise vinblastine concentrations. This may cause severe neutropenia, neurotoxicity, constipation or ileus.
What this interaction means in plain words
Nirmatrelvir and Vinblastine 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; Vinblastine belongs to Oncology.
Why it happens
Inhibition of CYP3A4 and P-glycoprotein reduces vinblastine metabolism and efflux, increasing exposure.
What to do
Avoid the combination where possible, and consider delaying vinblastine or choosing an alternative COVID-19 antiviral. If unavoidable, monitor blood counts and neurological and bowel function closely.
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 Vinblastine
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 Vinblastine?
MediHelp rates the interaction as major. Nirmatrelvir and Vinblastine 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 is given with ritonavir, a strong CYP3A4 and P-glycoprotein inhibitor, which can markedly raise vinblastine concentrations. This may cause severe neutropenia, neurotoxicity, constipation or ileus.
How serious is the interaction between Nirmatrelvir and Vinblastine?
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, and consider delaying vinblastine or choosing an alternative COVID-19 antiviral. If unavoidable, monitor blood counts and neurological and bowel function closely.
What other medicines interact with Vinblastine?
MediHelp also lists interactions of Vinblastine with, for example, Adenovirus types 4 and 7 live, Apalutamide, Atazanavir. The full list is on the Vinblastine page.
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