Dexamethasone and Ketoconazole Interaction
Drug interaction information between Dexamethasone and Ketoconazole.
Dexamethasone and Ketoconazole have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Dexamethasone 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 slows down how your body breaks down the steroid, which can cause the medicine to build up to high levels. This increases your risk of having serious side effects from the steroid.
FDA Label Information
Drugs which inhibit CYP 3A4 (e.g., ketoconazole, macrolide antibiotics such as erythromycin) have the potential to result in increased plasma concentrations of corticosteroids. Ketoconazole: Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to increased risk of corticosteroid side effects. In addition, ketoconazole alone can inhibit adrenal corticosteroid synthesis and may cause adrenal insufficiency during corticosteroid withdrawal.
Dexamethasone Also Interacts With
- Aspirin moderate
- Nirmatrelvir/Ritonavir moderate
- Warfarin minor
- Cyclosporine minor
- Hydrocortisone 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 Dexamethasone + Ketoconazole?
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 Dexamethasone's 21. In the moderate band specifically: Dexamethasone has 3 (also Aspirin, Nirmatrelvir/Ritonavir); Ketoconazole has 22 (also Alprazolam, Aprepitant, Budesonide/Formoterol, Fesoterodine).
What mechanism field is on file for Dexamethasone and Ketoconazole?
Ketoconazole slows down how your body breaks down the steroid, which can cause the medicine to build up to high levels. This increases your risk of having serious side effects from the steroid.
Ketoconazole carries more major-labeled pairs than Dexamethasone
SPL source-record counts only. This page's band is moderate · classes on file: Dexamethasone (Corticosteroid); Ketoconazole (Azole Antifungal).
Ketoconazole has 6 major-labeled pairs vs Dexamethasone's 0. This page itself is in the moderate band, not the major band.
0 major · 3 moderate · 18 minor · 21 total
- Other moderate peers for Dexamethasone
- Aspirin
- Nirmatrelvir/Ritonavir
6 major · 22 moderate · 85 minor · 113 total
- Other moderate peers for Ketoconazole
- Alprazolam
- Aprepitant
- Budesonide/Formoterol
- Fesoterodine
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.