Drug interactions
Phenytoin + Trofinetide
Severity: Minor
Phenytoin and Trofinetide: 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
Trofinetide may modestly raise phenytoin concentrations through weak enzyme inhibition. Because phenytoin has a narrow therapeutic index, small increases may matter.
What this interaction means in plain words
Phenytoin and Trofinetide have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Phenytoin belongs to Central Nervous System; Trofinetide belongs to Central Nervous System.
Why it happens
Trofinetide is a weak CYP3A4 inhibitor, slightly reducing phenytoin metabolism.
What to do
Monitor for signs of phenytoin toxicity and check levels if symptoms arise.
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
Other interactions of Trofinetide
Frequently asked questions
Can I take Phenytoin with Trofinetide?
MediHelp rates the interaction as minor. Phenytoin and Trofinetide have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Trofinetide may modestly raise phenytoin concentrations through weak enzyme inhibition. Because phenytoin has a narrow therapeutic index, small increases may matter.
How serious is the interaction between Phenytoin and Trofinetide?
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 for signs of phenytoin toxicity and check levels if symptoms arise.
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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