Desloratadine and Ketoconazole Interaction
Drug interaction information between Desloratadine and Ketoconazole.
Desloratadine and Ketoconazole have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Desloratadine 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.
How They Interact
Ketoconazole stops the body's natural process for breaking down desloratadine, which increases the amount of medicine in your bloodstream. This increase has not been shown to cause any dangerous side effects in clinical studies.
FDA Label Information
7 DRUG INTERACTIONS 7.1 Inhibitors of Cytochrome P450 3A4 In controlled clinical studies co-administration of desloratadine with ketoconazole, erythromycin, or azithromycin resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine.
Desloratadine Also Interacts With
- Fluoxetine minor
- Azithromycin minor
- Erythromycin minor
- Cimetidine minor
Ketoconazole Also Interacts With
- Alfuzosin major
- Dronedarone major
- Ranolazine major
- Saxagliptin major
- Sildenafil major
Frequently Asked Questions
What SPL severity band is on file for Desloratadine + 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 Desloratadine's 5. In the minor band specifically: Desloratadine has 5 (also Fluoxetine, Azithromycin, Erythromycin, Cimetidine); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).
What mechanism field is on file for Desloratadine and Ketoconazole?
Ketoconazole stops the body's natural process for breaking down desloratadine, which increases the amount of medicine in your bloodstream. This increase has not been shown to cause any dangerous side effects in clinical studies.
Ketoconazole carries more major-labeled pairs than Desloratadine
SPL source-record counts only. This page's band is minor · classes on file: Desloratadine (Second-Generation Antihistamine); Ketoconazole (Azole Antifungal).
Ketoconazole has 6 major-labeled pairs vs Desloratadine's 0. This page itself is in the minor band, not the major band.
0 major · 0 moderate · 5 minor · 5 total
- Other minor peers for Desloratadine
- Fluoxetine
- Azithromycin
- Erythromycin
- Cimetidine
6 major · 22 moderate · 85 minor · 113 total
- Other minor peers for Ketoconazole
- Abiraterone
- Acetaminophen/Oxycodone
- Alosetron
- Amphotericin B
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.