Oxybutynin and Clarithromycin Interaction
Drug interaction information between Oxybutynin and Clarithromycin.
Oxybutynin and Clarithromycin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Oxybutynin and Clarithromycin. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Clarithromycin blocks the natural enzymes that break down oxybutynin in your system. This leads to more of the drug staying in your body for a longer time.
What To Do
Tell your healthcare provider if you notice increased side effects, as they may need to change your dosage.
FDA Label Information
Other inhibitors of the cytochrome P450 3A4 enzyme system, such as antimycotic agents (e.g., itraconazole and miconazole) or macrolide antibiotics (e.g., erythromycin and clarithromycin), may alter oxybutynin mean pharmacokinetic parameters (i.e., C max and AUC).
Oxybutynin Also Interacts With
- Ketoconazole minor
- Erythromycin minor
- Itraconazole minor
- Metoclopramide minor
- Carbamazepine minor
Clarithromycin Also Interacts With
- Quetiapine major
- Pioglitazone major
- Fluconazole major
- Cyclosporine major
- Lurasidone major
Frequently Asked Questions
Can I take Oxybutynin and Clarithromycin together?
This is a minor interaction. Tell your healthcare provider if you notice increased side effects, as they may need to change your dosage.
How serious is the interaction between Oxybutynin and Clarithromycin?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Oxybutynin and Clarithromycin interact?
Clarithromycin blocks the natural enzymes that break down oxybutynin in your system. This leads to more of the drug staying in your body for a longer time.
Understanding the Oxybutynin and Clarithromycin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Oxybutynin belongs to the Anticholinergic / Antispasmodic class and Clarithromycin belongs to the Macrolide Antibiotic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Clarithromycin blocks the natural enzymes that break down oxybutynin in your system. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Oxybutynin has 7 total documented interactions on file in this dataset, and Clarithromycin has 81. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Tell your healthcare provider if you notice increased side effects, as they may need to change your dosage. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Oxybutynin or Clarithromycin based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.