Drug interactions
Budesonide + Fosphenytoin
Severity: Moderate
Budesonide and Fosphenytoin: moderate 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
Fosphenytoin, via phenytoin, induces CYP3A4 and may reduce budesonide exposure and effectiveness. Loss of disease control in asthma or Crohn disease may occur.
What this interaction means in plain words
Budesonide and Fosphenytoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Budesonide belongs to Respiratory; Fosphenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4 and P-glycoprotein, increasing budesonide metabolism and efflux.
What to do
Monitor clinical response to budesonide and increase the dose or choose an alternative therapy if control is lost. Reassess when phenytoin is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Budesonide
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 Budesonide with Fosphenytoin?
MediHelp rates the interaction as moderate. Budesonide and Fosphenytoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Fosphenytoin, via phenytoin, induces CYP3A4 and may reduce budesonide exposure and effectiveness. Loss of disease control in asthma or Crohn disease may occur.
How serious is the interaction between Budesonide and Fosphenytoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clinical response to budesonide and increase the dose or choose an alternative therapy if control is lost. Reassess when phenytoin is stopped.
What other medicines interact with Budesonide?
MediHelp also lists interactions of Budesonide with, for example, Aldesleukin, Atazanavir, Bcg vaccine live. The full list is on the Budesonide page.
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