Drug interactions
Fosphenytoin + Ramelteon
Severity: Minor
Fosphenytoin and Ramelteon: 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
Fosphenytoin (phenytoin) induces CYP enzymes including CYP3A4 and may lower ramelteon concentrations, potentially reducing its hypnotic effect.
What this interaction means in plain words
Fosphenytoin and Ramelteon have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fosphenytoin belongs to Central Nervous System; Ramelteon belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 (and other CYPs) by phenytoin increases ramelteon clearance.
What to do
Monitor for loss of sleep-promoting effect; consider an alternative hypnotic if ramelteon becomes ineffective.
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 Ramelteon
- Calcium / magnesium / potassium / sodium oxybates + Ramelteon Contraindicated
- Fluvoxamine + Ramelteon Contraindicated
- Ramelteon + Sodium oxybate Contraindicated
- Alfentanil + Ramelteon Moderate
- Amitriptyline + Ramelteon Moderate
- Amobarbital + Ramelteon Moderate
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Ramelteon?
MediHelp rates the interaction as minor. Fosphenytoin and Ramelteon have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Fosphenytoin (phenytoin) induces CYP enzymes including CYP3A4 and may lower ramelteon concentrations, potentially reducing its hypnotic effect.
How serious is the interaction between Fosphenytoin and Ramelteon?
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 loss of sleep-promoting effect; consider an alternative hypnotic if ramelteon becomes ineffective.
What other medicines interact with Ramelteon?
MediHelp also lists interactions of Ramelteon with, for example, Calcium / magnesium / potassium / sodium oxybates, Fluvoxamine, Sodium oxybate. The full list is on the Ramelteon page.
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