Tolterodine and Estradiol Interaction
Drug interaction information between Tolterodine and Estradiol.
Tolterodine and Estradiol have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Tolterodine and Estradiol. 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
Tolterodine does not interfere with how birth control medications work or change the amount of hormone in your body.
What To Do
No changes to your medication schedule or dose are necessary when taking these together.
FDA Label Information
7.3 Other Interactions No clinically relevant interactions have been observed when tolterodine was co-administered with warfarin, with a combined oral contraceptive drug containing ethinyl estradiol and levonorgestrel, or with diuretics [see Clinical Pharmacology (12.3) ] . Oral Contraceptives Tolterodine immediate release 4 mg (2 mg bid) had no effect on the pharmacokinetics of an oral contraceptive (ethinyl estradiol 30 µg/levonorgestrel 150 µg) as evidenced by the monitoring of ethinyl estradiol and levonorgestrel over a 2-month period in healthy female volunteers.
Tolterodine Also Interacts With
- Clarithromycin moderate
- Omeprazole minor
- Hydrochlorothiazide minor
- Fluoxetine minor
- Furosemide minor
Estradiol Also Interacts With
- Drospirenone/Ethinyl Estradiol major
- Glecaprevir/Pibrentasvir moderate
- Etonogestrel moderate
- Tacrolimus Topical moderate
- Rosuvastatin minor
Frequently Asked Questions
Can I take Tolterodine and Estradiol together?
This is a minor interaction. No changes to your medication schedule or dose are necessary when taking these together.
How serious is the interaction between Tolterodine and Estradiol?
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 Tolterodine and Estradiol interact?
Tolterodine does not interfere with how birth control medications work or change the amount of hormone in your body.
Understanding the Tolterodine and Estradiol Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Tolterodine belongs to the Anticholinergic (Overactive Bladder) class and Estradiol belongs to the Estrogen Hormone class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Tolterodine does not interfere with how birth control medications work or change the amount of hormone in your body. 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. Tolterodine has 15 total documented interactions on file in this dataset, and Estradiol has 54. 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: No changes to your medication schedule or dose are necessary when taking these together. 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 Tolterodine or Estradiol 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.