Drug interactions
Fluconazole + Oxybutynin
Severity: Moderate
Fluconazole and Oxybutynin: 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
Fluconazole inhibits CYP3A4 and may raise oxybutynin concentrations. This could increase anticholinergic effects such as dry mouth, constipation, confusion and drowsiness, particularly in older adults.
What this interaction means in plain words
Fluconazole and Oxybutynin 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.
Fluconazole belongs to Anti Fungals; Oxybutynin belongs to Genitourinary.
Why it happens
Fluconazole inhibits intestinal and hepatic CYP3A4, reducing oxybutynin metabolism.
What to do
Monitor for anticholinergic adverse effects, especially in elderly patients, and reduce the oxybutynin dose if they occur.
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 Oxybutynin
Other interactions of Fluconazole
- Dihydroergotamine intranasal + Fluconazole Contraindicated
- Dihydroergotamine + Fluconazole Contraindicated
- Dofetilide + Fluconazole Contraindicated
- Domperidone + Fluconazole Contraindicated
- Dronedarone + Fluconazole Contraindicated
- Erythromycin + Fluconazole Contraindicated
Frequently asked questions
Can I take Fluconazole with Oxybutynin?
MediHelp rates the interaction as moderate. Fluconazole and Oxybutynin 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. Fluconazole inhibits CYP3A4 and may raise oxybutynin concentrations. This could increase anticholinergic effects such as dry mouth, constipation, confusion and drowsiness, particularly in older adults.
How serious is the interaction between Fluconazole and Oxybutynin?
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 for anticholinergic adverse effects, especially in elderly patients, and reduce the oxybutynin dose if they occur.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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