Drug interactions
Fosaprepitant + Montelukast
Severity: Minor
Fosaprepitant and Montelukast: 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
Fosaprepitant, converted to aprepitant, is a moderate CYP3A4 inhibitor after single doses, so montelukast levels could rise slightly. Given the single or short-course use and montelukast's safety margin, the effect is unlikely to matter.
What this interaction means in plain words
Fosaprepitant and Montelukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fosaprepitant belongs to Gastrointestinal Tract; Montelukast belongs to Respiratory.
Why it happens
Aprepitant inhibits CYP3A4, modestly reducing montelukast metabolism.
What to do
No dose adjustment is required. Monitor for adverse effects if used repeatedly.
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 Montelukast
- Apalutamide + Montelukast Moderate
- Carbamazepine + Montelukast Moderate
- Deferasirox + Montelukast Moderate
- Enzalutamide + Montelukast Moderate
- Fosphenytoin + Montelukast Moderate
- Gemfibrozil + Montelukast Moderate
Other interactions of Fosaprepitant
- Flibanserin + Fosaprepitant Contraindicated
- Fosaprepitant + Pimozide Contraindicated
- Alprazolam + Fosaprepitant Moderate
- Amiodarone + Fosaprepitant Moderate
- Amobarbital + Fosaprepitant Moderate
- Apalutamide + Fosaprepitant Moderate
Frequently asked questions
Can I take Fosaprepitant with Montelukast?
MediHelp rates the interaction as minor. Fosaprepitant and Montelukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Fosaprepitant, converted to aprepitant, is a moderate CYP3A4 inhibitor after single doses, so montelukast levels could rise slightly. Given the single or short-course use and montelukast's safety margin, the effect is unlikely to matter.
How serious is the interaction between Fosaprepitant and Montelukast?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is required. Monitor for adverse effects if used repeatedly.
What other medicines interact with Montelukast?
MediHelp also lists interactions of Montelukast with, for example, Apalutamide, Carbamazepine, Deferasirox. The full list is on the Montelukast page.
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