Drug interactions
Oxybutynin + Zafirlukast
Severity: Minor
Oxybutynin and Zafirlukast: 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
Oxybutynin is metabolized by CYP3A4, which zafirlukast may weakly inhibit. A clinically important rise in anticholinergic effects is unlikely.
What this interaction means in plain words
Oxybutynin and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Oxybutynin belongs to Genitourinary; Zafirlukast belongs to Respiratory.
Why it happens
Possible weak CYP3A4 inhibition by zafirlukast reducing oxybutynin clearance.
What to do
No adjustment is needed. Watch for dry mouth, constipation or confusion, especially in older patients.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Oxybutynin and Zafirlukast, 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 14 days on the web. No card needed.
Other interactions of Zafirlukast
- Pimozide + Zafirlukast Contraindicated
- Lomitapide + Zafirlukast Major
- Nilotinib + Zafirlukast Major
- Warfarin + Zafirlukast Major
- Apalutamide + Zafirlukast Moderate
- Carbamazepine + Zafirlukast Moderate
Other interactions of Oxybutynin
Frequently asked questions
Can I take Oxybutynin with Zafirlukast?
MediHelp rates the interaction as minor. Oxybutynin and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Oxybutynin is metabolized by CYP3A4, which zafirlukast may weakly inhibit. A clinically important rise in anticholinergic effects is unlikely.
How serious is the interaction between Oxybutynin and Zafirlukast?
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 adjustment is needed. Watch for dry mouth, constipation or confusion, especially in older patients.
What other medicines interact with Zafirlukast?
MediHelp also lists interactions of Zafirlukast with, for example, Pimozide, Lomitapide, Nilotinib. The full list is on the Zafirlukast 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.
