Drug interactions
Budesonide + Phenytoin
Severity: Moderate
Budesonide and Phenytoin: 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
Phenytoin is a strong inducer of CYP3A4 and may substantially lower budesonide concentrations, reducing its therapeutic effect. This has been shown for other corticosteroids and is expected for budesonide, especially oral forms.
What this interaction means in plain words
Budesonide and Phenytoin 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; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4 and P-glycoprotein, increasing budesonide clearance.
What to do
Monitor for loss of budesonide efficacy and increase the dose or consider an alternative if disease control is lost. Reassess the dose if 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 Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Budesonide with Phenytoin?
MediHelp rates the interaction as moderate. Budesonide and Phenytoin 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. Phenytoin is a strong inducer of CYP3A4 and may substantially lower budesonide concentrations, reducing its therapeutic effect. This has been shown for other corticosteroids and is expected for budesonide, especially oral forms.
How serious is the interaction between Budesonide and Phenytoin?
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 for loss of budesonide efficacy and increase the dose or consider an alternative if disease control is lost. Reassess the dose if 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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