Drug interactions
Fluticasone-salmeterol + Fosphenytoin
Severity: Minor
Fluticasone-salmeterol and Fosphenytoin: 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 is converted to phenytoin, a CYP3A4 inducer, which may speed the metabolism of fluticasone and salmeterol. Systemic exposure and possibly effect of both components could be reduced, though inhaled doses have low systemic bioavailability so the practical impact is probably small.
What this interaction means in plain words
Fluticasone-salmeterol and Fosphenytoin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fluticasone-salmeterol belongs to Respiratory; Fosphenytoin belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 by phenytoin increases clearance of fluticasone and salmeterol.
What to do
Monitor asthma or COPD control and step up therapy if symptoms worsen.
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 Fluticasone-salmeterol
- Darunavir + Fluticasone-salmeterol Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Fluticasone-salmeterol Contraindicated
- Fluticasone-salmeterol + Fosamprenavir Contraindicated
- Fluticasone-salmeterol + Indinavir Contraindicated
- Fluticasone-salmeterol + Lopinavir Contraindicated
- Fluticasone-salmeterol + Nelfinavir Contraindicated
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 Fluticasone-salmeterol with Fosphenytoin?
MediHelp rates the interaction as minor. Fluticasone-salmeterol and Fosphenytoin 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 is converted to phenytoin, a CYP3A4 inducer, which may speed the metabolism of fluticasone and salmeterol. Systemic exposure and possibly effect of both components could be reduced, though inhaled doses have low systemic bioavailability so the practical impact is probably small.
How serious is the interaction between Fluticasone-salmeterol and Fosphenytoin?
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 asthma or COPD control and step up therapy if symptoms worsen.
What other medicines interact with Fluticasone-salmeterol?
MediHelp also lists interactions of Fluticasone-salmeterol with, for example, Darunavir, Elvitegravir / cobicistat / emtricitabine / tenofovir df, Fosamprenavir. The full list is on the Fluticasone-salmeterol page.
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