Drug interactions
Ritonavir + Vinblastine
Severity: Major
Ritonavir 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
Ritonavir strongly inhibits CYP3A4 and P-glycoprotein, which can substantially raise vinblastine levels. Severe myelosuppression, neurotoxicity and ileus have been reported with vinca alkaloids and protease inhibitors.
What this interaction means in plain words
Ritonavir 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.
Ritonavir belongs to Anti Virals; Vinblastine belongs to Oncology.
Why it happens
Ritonavir inhibits CYP3A4 and P-glycoprotein, reducing vinblastine clearance.
What to do
Avoid the combination where possible, or reduce the vinblastine dose with close monitoring of blood counts and neurological and bowel function. Consider a non-boosted antiretroviral regimen.
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 Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Ritonavir with Vinblastine?
MediHelp rates the interaction as major. Ritonavir 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. Ritonavir strongly inhibits CYP3A4 and P-glycoprotein, which can substantially raise vinblastine levels. Severe myelosuppression, neurotoxicity and ileus have been reported with vinca alkaloids and protease inhibitors.
How serious is the interaction between Ritonavir 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, or reduce the vinblastine dose with close monitoring of blood counts and neurological and bowel function. Consider a non-boosted antiretroviral regimen.
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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