Drug interactions
Pirfenidone + Zileuton
Severity: Moderate
Pirfenidone and Zileuton: 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
Pirfenidone is metabolized mainly by CYP1A2, and inhibitors increase its exposure and the risk of nausea, photosensitivity, rash and liver enzyme elevation. Zileuton is a weak CYP1A2 inhibitor, so the effect is smaller than with strong inhibitors.
What this interaction means in plain words
Pirfenidone and Zileuton 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.
Pirfenidone belongs to Miscellaneous; Zileuton belongs to Respiratory.
Why it happens
Zileuton inhibits CYP1A2, reducing pirfenidone clearance.
What to do
Monitor liver function and tolerability, and reduce the pirfenidone dose if adverse effects emerge. Consider an alternative to zileuton if effects persist.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Pirfenidone and Zileuton, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Zileuton
- Fezolinetant + Zileuton Contraindicated
- Pimozide + Zileuton Contraindicated
- Alosetron + Zileuton Major
- Clozapine + Zileuton Major
- Lomitapide + Zileuton Major
- Lonafarnib + Zileuton Major
Other interactions of Pirfenidone
Frequently asked questions
Can I take Pirfenidone with Zileuton?
MediHelp rates the interaction as moderate. Pirfenidone and Zileuton 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. Pirfenidone is metabolized mainly by CYP1A2, and inhibitors increase its exposure and the risk of nausea, photosensitivity, rash and liver enzyme elevation. Zileuton is a weak CYP1A2 inhibitor, so the effect is smaller than with strong inhibitors.
How serious is the interaction between Pirfenidone and Zileuton?
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 liver function and tolerability, and reduce the pirfenidone dose if adverse effects emerge. Consider an alternative to zileuton if effects persist.
What other medicines interact with Zileuton?
MediHelp also lists interactions of Zileuton with, for example, Fezolinetant, Pimozide, Alosetron. The full list is on the Zileuton page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
