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. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
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.
What To Do
Use this combination with caution as it may cause increased sleepiness. Your doctor may need to lower your dose of midazolam.
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
Can I take Midazolam and Ketoconazole together?
This is a moderate interaction. Use this combination with caution as it may cause increased sleepiness. Your doctor may need to lower your dose of midazolam.
How serious is the interaction between Midazolam and Ketoconazole?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Midazolam and Ketoconazole 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.
Understanding the Midazolam and Ketoconazole Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Midazolam belongs to the Benzodiazepine class and Ketoconazole belongs to the Azole Antifungal class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Ketoconazole blocks the specific liver enzyme that your body uses to break down midazolam. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Midazolam has 39 total documented interactions on file in this dataset, and Ketoconazole has 113. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Use this combination with caution as it may cause increased sleepiness. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Midazolam or Ketoconazole based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.