Drug interactions
Mycophenolate + Phenytoin
Severity: Minor
Mycophenolate and Phenytoin: minor 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
Mycophenolate's metabolite can displace phenytoin from albumin in vitro, slightly raising the free fraction. Phenytoin may also lower mycophenolic acid exposure. The clinical significance of the binding shift is thought to be small.
What this interaction means in plain words
Mycophenolate and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Protein binding displacement of phenytoin by mycophenolic acid glucuronide or mycophenolic acid.
What to do
Monitor free phenytoin concentrations if toxicity is suspected, especially with hypoalbuminemia or renal impairment.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Mycophenolate with Phenytoin?
MediHelp rates the interaction as minor. Mycophenolate and Phenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Mycophenolate's metabolite can displace phenytoin from albumin in vitro, slightly raising the free fraction. Phenytoin may also lower mycophenolic acid exposure. The clinical significance of the binding shift is thought to be small.
How serious is the interaction between Mycophenolate and Phenytoin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor free phenytoin concentrations if toxicity is suspected, especially with hypoalbuminemia or renal impairment.
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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