Ketoconazole and Budesonide/Formoterol Interaction
Drug interaction information between Ketoconazole and Budesonide/Formoterol.
Ketoconazole and Budesonide/Formoterol have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Ketoconazole and Budesonide/Formoterol. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Ketoconazole blocks the specific liver enzyme that normally breaks down budesonide. This causes the steroid levels in your body to rise higher than intended.
FDA Label Information
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally administered budesonide increased. Caution should be exercised when considering the coadministration of SYMBICORT with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) [see Warnings and Precautions (5.9) ] .
Ketoconazole Also Interacts With
- Alfuzosin major
- Dronedarone major
- Ranolazine major
- Saxagliptin major
- Sildenafil major
Budesonide/Formoterol Also Interacts With
- Clarithromycin moderate
- Itraconazole moderate
- Formoterol moderate
- Budesonide minor
Frequently Asked Questions
What SPL severity band is on file for Ketoconazole + Budesonide/Formoterol?
Compiled FDA labeling labels this pair moderate. 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 Budesonide/Formoterol's 5. In the moderate band specifically: Ketoconazole has 22 (also Alprazolam, Aprepitant, Dexamethasone, Fesoterodine); Budesonide/Formoterol has 4 (also Clarithromycin, Itraconazole, Formoterol).
What mechanism field is on file for Ketoconazole and Budesonide/Formoterol?
Ketoconazole blocks the specific liver enzyme that normally breaks down budesonide. This causes the steroid levels in your body to rise higher than intended.
Ketoconazole carries more major-labeled pairs than Budesonide/Formoterol
SPL source-record counts only. This page's band is moderate · classes on file: Ketoconazole (Azole Antifungal); Budesonide/Formoterol (Corticosteroid / Long-Acting Beta-2 Agonist Combination).
Ketoconazole has 6 major-labeled pairs vs Budesonide/Formoterol's 0. This page itself is in the moderate band, not the major band.
6 major · 22 moderate · 85 minor · 113 total
- Other moderate peers for Ketoconazole
- Alprazolam
- Aprepitant
- Dexamethasone
- Fesoterodine
0 major · 4 moderate · 1 minor · 5 total
- Other moderate peers for Budesonide/Formoterol
- Clarithromycin
- Itraconazole
- Formoterol
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.
Read our methodology - how this data is sourced, computed, and verified.