Drug interactions
Axitinib + Fosphenytoin
Severity: Major
Axitinib and Fosphenytoin: 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
Fosphenytoin, converted to phenytoin, is a strong CYP3A4 inducer and can markedly lower axitinib concentrations. This may lead to loss of antitumor efficacy.
What this interaction means in plain words
Axitinib and Fosphenytoin 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.
Axitinib belongs to Oncology; Fosphenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4, increasing axitinib clearance.
What to do
Use a non-enzyme-inducing anticonvulsant such as levetiracetam; if unavoidable, monitor response and consider axitinib dose increase with careful tolerability monitoring.
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 Axitinib
- Amobarbital + Axitinib Major
- Apalutamide + Axitinib Major
- Atazanavir + Axitinib Major
- Axitinib + Carbamazepine Major
- Axitinib + Clarithromycin Major
- Axitinib + Cobicistat Major
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Axitinib with Fosphenytoin?
MediHelp rates the interaction as major. Axitinib and Fosphenytoin 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. Fosphenytoin, converted to phenytoin, is a strong CYP3A4 inducer and can markedly lower axitinib concentrations. This may lead to loss of antitumor efficacy.
How serious is the interaction between Axitinib and Fosphenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-enzyme-inducing anticonvulsant such as levetiracetam; if unavoidable, monitor response and consider axitinib dose increase with careful tolerability monitoring.
What other medicines interact with Axitinib?
MediHelp also lists interactions of Axitinib with, for example, Amobarbital, Apalutamide, Atazanavir. The full list is on the Axitinib page.
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