Ethinyl Estradiol and Ketoconazole Interaction

Drug interaction information between Ethinyl Estradiol and Ketoconazole.

Ethinyl Estradiol and Ketoconazole have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Ethinyl Estradiol and Ketoconazole. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Ethinyl Estradiol

Combined Oral Contraceptive

Drug B

Ketoconazole

Azole Antifungal

How They Interact

Ketoconazole blocks a specific liver enzyme that normally clears birth control hormones from your body. This leads to higher levels of the hormones in your system.

FDA Label Information

CYP3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels.

Frequently Asked Questions

What SPL severity band is on file for Ethinyl Estradiol/Levonorgestrel + Ketoconazole?

Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Ketoconazole has 113 labeled pairs on file vs Ethinyl Estradiol's 14. In the minor band specifically: Ethinyl Estradiol has 14 (also Atorvastatin, Estradiol, Lamotrigine, Topiramate); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).

What mechanism field is on file for Ethinyl Estradiol/Levonorgestrel and Ketoconazole?

Ketoconazole blocks a specific liver enzyme that normally clears birth control hormones from your body. This leads to higher levels of the hormones in your system.

Ketoconazole carries more major-labeled pairs than Ethinyl Estradiol

SPL source-record counts only. This page's band is minor · classes on file: Ethinyl Estradiol (Combined Oral Contraceptive); Ketoconazole (Azole Antifungal).

Ketoconazole has 6 major-labeled pairs vs Ethinyl Estradiol's 0. This page itself is in the minor band, not the major band.

Ethinyl Estradiol

0 major · 0 moderate · 14 minor · 14 total

Ketoconazole

6 major · 22 moderate · 85 minor · 113 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.