Quetiapine and Ketoconazole Interaction
Drug interaction information between Quetiapine and Ketoconazole.
Quetiapine and Ketoconazole have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Quetiapine 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 the body's ability to break down quetiapine, which causes the level of quetiapine in your blood to rise significantly. This increase can lead to a higher risk of side effects.
FDA Label Information
7 DRUG INTERACTIONS Concomitant use of strong CYP3A4 inhibitors: Reduce quetiapine dose to one sixth when coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) ( 2.5 , 7.1 , 12.3 ) Concomitant use of strong CYP3A4 inducers: Increase quetiapine dose up to 5 fold when used in combination with a chronic treatment (more than 7-14 days) of potent CYP3A4 inducers (e.g., phenytoin, rifampin, St. Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype CYP3A4...
Quetiapine Also Interacts With
- Clarithromycin major
- Darunavir moderate
- Carbamazepine minor
- Rifampin minor
- Itraconazole 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 Quetiapine + 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 Quetiapine's 9. In the minor band specifically: Quetiapine has 7 (also Carbamazepine, Rifampin, Itraconazole, Dopamine); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).
What mechanism field is on file for Quetiapine and Ketoconazole?
Ketoconazole slows down the body's ability to break down quetiapine, which causes the level of quetiapine in your blood to rise significantly. This increase can lead to a higher risk of side effects.
Ketoconazole carries more major-labeled pairs than Quetiapine
SPL source-record counts only. This page's band is minor · classes on file: Quetiapine (Atypical Antipsychotic); Ketoconazole (Azole Antifungal).
Ketoconazole has 6 major-labeled pairs vs Quetiapine's 1. This page itself is in the minor band, not the major band.
1 major · 1 moderate · 7 minor · 9 total
- Other minor peers for Quetiapine
- Carbamazepine
- Rifampin
- Itraconazole
- Dopamine
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.