Drug interactions
Buspirone + Phenytoin
Severity: Moderate
Buspirone and Phenytoin: moderate 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
Phenytoin is an inducer of CYP3A4 and can reduce buspirone exposure, potentially leading to reduced anxiolytic efficacy. The effect is predicted from the pharmacology of related inducers.
What this interaction means in plain words
Buspirone and Phenytoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Buspirone belongs to Central Nervous System; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4, accelerating the metabolism of buspirone.
What to do
Monitor clinical response to buspirone and increase the dose as needed. Lower the dose again if phenytoin is withdrawn.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Buspirone
- Buspirone + Isocarboxazid Contraindicated
- Buspirone + Linezolid Contraindicated
- Buspirone + Phenelzine Contraindicated
- Buspirone + Procarbazine Contraindicated
- Buspirone + Selegiline Contraindicated
- Buspirone + Selegiline transdermal 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 Buspirone with Phenytoin?
MediHelp rates the interaction as moderate. Buspirone and Phenytoin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenytoin is an inducer of CYP3A4 and can reduce buspirone exposure, potentially leading to reduced anxiolytic efficacy. The effect is predicted from the pharmacology of related inducers.
How serious is the interaction between Buspirone and Phenytoin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clinical response to buspirone and increase the dose as needed. Lower the dose again if phenytoin is withdrawn.
What other medicines interact with Buspirone?
MediHelp also lists interactions of Buspirone with, for example, Isocarboxazid, Linezolid, Phenelzine. The full list is on the Buspirone page.
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