Drug interactions
Lurasidone + Phenytoin
Severity: Contraindicated
Lurasidone and Phenytoin: contraindicated interaction.
Last updated Sources: US FDA label
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 is expected to substantially lower lurasidone exposure. Lurasidone labeling advises against use with strong CYP3A4 inducers because efficacy is likely lost.
What this interaction means in plain words
Lurasidone and Phenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Lurasidone belongs to Central Nervous System; Phenytoin belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 by phenytoin increasing lurasidone clearance.
What to do
Do not combine; choose an antipsychotic less dependent on CYP3A4 metabolism.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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References
Other interactions of Lurasidone
- Apalutamide + Lurasidone Contraindicated
- Atazanavir + Lurasidone Contraindicated
- Carbamazepine + Lurasidone Contraindicated
- Clarithromycin + Lurasidone Contraindicated
- Cobicistat + Lurasidone Contraindicated
- Conivaptan + Lurasidone Contraindicated
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 Lurasidone with Phenytoin?
MediHelp rates the interaction as contraindicated. Lurasidone and Phenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Phenytoin induces CYP3A4 and is expected to substantially lower lurasidone exposure. Lurasidone labeling advises against use with strong CYP3A4 inducers because efficacy is likely lost.
How serious is the interaction between Lurasidone and Phenytoin?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not combine; choose an antipsychotic less dependent on CYP3A4 metabolism.
What other medicines interact with Lurasidone?
MediHelp also lists interactions of Lurasidone with, for example, Apalutamide, Atazanavir, Carbamazepine. The full list is on the Lurasidone page.
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