Triazole antifungal
Fluconazole and smoking: how tobacco affects the medication
Tobacco smoking is one of the most underappreciated drug-drug interactions in chronic medication. Compounds in tobacco smoke induce hepatic enzymes (especially CYP1A2) and can shift the plasma concentration of many medications, including Fluconazole (Fluconazole), enough to matter clinically at 50mg, 100mg, 150mg, 200mg.
How smoking affects Fluconazole
Polycyclic aromatic hydrocarbons in tobacco smoke induce CYP1A2 and to a lesser extent other CYP enzymes. For medications metabolised primarily by CYP1A2, smokers can have plasma levels 30–50% lower than non-smokers at the same dose. Whether Fluconazole is affected depends on its specific metabolic pathway. Fluconazole is a triazole antifungal that inhibits the cytochrome P450-dependent enzyme lanosterol 14-alpha-demethylase, blocking the synthesis of ergosterol from lanosterol.
Practical guidance
According to the prescribing information for Fluconazole, smoking status should be disclosed at every dose review of Fluconazole. Stopping smoking can paradoxically raise plasma levels of CYP1A2-metabolised medications enough to cause new-onset side effects within days, and may require a temporary dose reduction. The 50mg, 100mg, 150mg, 200mg starting strength assumed in the prescribing information is usually for non-smokers.
Frequently asked questions
Does smoking change how Fluconazole works? ▾
For medications metabolised by CYP1A2, yes — smokers may need higher doses or have reduced effect at standard 50mg, 100mg, 150mg, 200mg. Whether Fluconazole specifically is affected depends on whether Fluconazole uses CYP1A2. The prescribing information notes any documented interaction.
Will I need to adjust Fluconazole if I quit smoking? ▾
Possibly, if Fluconazole is one of the medications affected by CYP1A2 induction. Stopping smoking restores CYP1A2 to normal within days, raising plasma levels and potentially causing side effects. Discuss the timing of any dose adjustment with the prescriber when planning to quit.
Products containing Fluconazole
More on Fluconazole
- With alcoholFluconazole and alcohol — is it safe to drink?
- With foodShould Fluconazole be taken with food?
- Side effectsFluconazole side effects: common, rare and warning signs
- Dosage guideFluconazole dosage guide: how much to take and when
- OnsetHow fast does Fluconazole start working?
- DurationHow long does Fluconazole last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.