Drug interactions
Buprenorphine transdermal + Phenytoin
Severity: Moderate
Buprenorphine transdermal 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 induces CYP3A4 and can lower buprenorphine concentrations from the patch. This may cause reduced analgesia or withdrawal symptoms.
What this interaction means in plain words
Buprenorphine transdermal 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.
Why it happens
CYP3A4 induction by phenytoin increases buprenorphine metabolism.
What to do
Monitor pain control and withdrawal symptoms and consider a higher buprenorphine dose or supplemental analgesia. Reassess the dose if phenytoin is discontinued.
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 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 Buprenorphine transdermal with Phenytoin?
MediHelp rates the interaction as moderate. Buprenorphine transdermal 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 induces CYP3A4 and can lower buprenorphine concentrations from the patch. This may cause reduced analgesia or withdrawal symptoms.
How serious is the interaction between Buprenorphine transdermal 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 pain control and withdrawal symptoms and consider a higher buprenorphine dose or supplemental analgesia. Reassess the dose if phenytoin is discontinued.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
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