Drug interactions
Cigarette smoking + Pirfenidone
Severity: Moderate
Cigarette smoking and Pirfenidone: 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
Smoking induces CYP1A2, the main enzyme clearing pirfenidone, which lowers pirfenidone exposure and may reduce efficacy. The legacy framing as inhibition is mistaken; smoking induces rather than inhibits CYP1A2.
What this interaction means in plain words
Cigarette smoking and Pirfenidone 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.
Why it happens
Induction of CYP1A2 by polycyclic aromatic hydrocarbons in tobacco smoke increases pirfenidone clearance.
What to do
Advise patients to stop smoking before and during pirfenidone therapy. If smoking continues, monitor for reduced clinical response and reassess the need for dose adjustment.
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 Pirfenidone
Frequently asked questions
Can I take Cigarette smoking with Pirfenidone?
MediHelp rates the interaction as moderate. Cigarette smoking and Pirfenidone 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. Smoking induces CYP1A2, the main enzyme clearing pirfenidone, which lowers pirfenidone exposure and may reduce efficacy. The legacy framing as inhibition is mistaken; smoking induces rather than inhibits CYP1A2.
How serious is the interaction between Cigarette smoking and Pirfenidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to stop smoking before and during pirfenidone therapy. If smoking continues, monitor for reduced clinical response and reassess the need for dose adjustment.
What other medicines interact with Pirfenidone?
MediHelp also lists interactions of Pirfenidone with, for example, Carbamazepine, Ciprofloxacin, Fluvoxamine. The full list is on the Pirfenidone page.
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