Drug interactions
Lonapegsomatropin + Phenytoin
Severity: Minor
Lonapegsomatropin 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
Growth hormone products may increase cytochrome P450 activity, which could speed the metabolism of phenytoin and lower its serum concentrations. The effect is based on limited data, but phenytoin has a narrow therapeutic index, so a loss of seizure control is possible.
What this interaction means in plain words
Lonapegsomatropin 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.
Lonapegsomatropin belongs to Endocrine; Phenytoin belongs to Central Nervous System.
Why it happens
Growth hormone may induce CYP-mediated metabolism, potentially increasing phenytoin clearance.
What to do
Check phenytoin serum levels when starting or changing lonapegsomatropin therapy, and adjust the phenytoin dose if levels fall or seizure control worsens.
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 Lonapegsomatropin
Frequently asked questions
Can I take Lonapegsomatropin with Phenytoin?
MediHelp rates the interaction as minor. Lonapegsomatropin 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. Growth hormone products may increase cytochrome P450 activity, which could speed the metabolism of phenytoin and lower its serum concentrations. The effect is based on limited data, but phenytoin has a narrow therapeutic index, so a loss of seizure control is possible.
How serious is the interaction between Lonapegsomatropin 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: Check phenytoin serum levels when starting or changing lonapegsomatropin therapy, and adjust the phenytoin dose if levels fall or seizure control worsens.
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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