Drug interactions
Paclitaxel + Ritonavir
Severity: Major
Paclitaxel and Ritonavir: 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 inhibits the enzymes and transporters that clear paclitaxel, so paclitaxel exposure can rise. This may increase myelosuppression and peripheral neuropathy.
What this interaction means in plain words
Paclitaxel and 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.
Paclitaxel belongs to Oncology; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir inhibits CYP3A4 and P-glycoprotein and may also inhibit CYP2C8, reducing paclitaxel metabolism and efflux.
What to do
Avoid the combination if an alternative antiretroviral is possible. If it is unavoidable, monitor blood counts and neuropathy closely and reduce the paclitaxel dose as needed.
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 Paclitaxel
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 Paclitaxel with Ritonavir?
MediHelp rates the interaction as major. Paclitaxel and 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 inhibits the enzymes and transporters that clear paclitaxel, so paclitaxel exposure can rise. This may increase myelosuppression and peripheral neuropathy.
How serious is the interaction between Paclitaxel and 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: Avoid the combination if an alternative antiretroviral is possible. If it is unavoidable, monitor blood counts and neuropathy closely and reduce the paclitaxel dose as needed.
What other medicines interact with Paclitaxel?
MediHelp also lists interactions of Paclitaxel with, for example, Adenovirus types 4 and 7 live, Cobicistat, Cyclosporine. The full list is on the Paclitaxel page.
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