Midazolam and Ketoconazole Interaction
Drug interaction information between Midazolam and Ketoconazole.
Midazolam and Ketoconazole have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Midazolam 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 blocks the specific liver enzyme that your body uses to break down midazolam. This can cause the midazolam to build up in your system and make its effects much stronger.
FDA Label Information
Other Drug Interactions Caution is advised when midazolam is administered concomitantly with drugs that are known to inhibit the P450-3A4 enzyme system such as cimetidine (not ranitidine), erythromycin, diltiazem, verapamil, ketoconazole and itraconazole.
Midazolam Also Interacts With
- Darunavir major
- Itraconazole major
- Nirmatrelvir/Ritonavir major
- Verapamil moderate
- Erythromycin moderate
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 Midazolam + 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 Midazolam's 39. In the moderate band specifically: Midazolam has 9 (also Verapamil, Erythromycin, Ranitidine, Cimetidine); Ketoconazole has 22 (also Alprazolam, Aprepitant, Budesonide/Formoterol, Dexamethasone).
What mechanism field is on file for Midazolam and Ketoconazole?
Ketoconazole blocks the specific liver enzyme that your body uses to break down midazolam. This can cause the midazolam to build up in your system and make its effects much stronger.
Ketoconazole carries more major-labeled pairs than Midazolam
SPL source-record counts only. This page's band is moderate · classes on file: Midazolam (Benzodiazepine); Ketoconazole (Azole Antifungal).
Ketoconazole has 6 major-labeled pairs vs Midazolam's 3. This page itself is in the moderate band, not the major band.
3 major · 9 moderate · 27 minor · 39 total
- Other moderate peers for Midazolam
- Verapamil
- Erythromycin
- Ranitidine
- Cimetidine
6 major · 22 moderate · 85 minor · 113 total
- Other moderate peers for Ketoconazole
- Alprazolam
- Aprepitant
- Budesonide/Formoterol
- Dexamethasone
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.