Famotidine and Ketoconazole Interaction
Drug interaction information between Famotidine and Ketoconazole.
Famotidine and Ketoconazole have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Famotidine 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
Famotidine reduces stomach acid, which can prevent ketoconazole from being absorbed into your system.
FDA Label Information
See the prescribing information for other drugs dependent on gastric pH for absorption for administration instructions, including atazanavir, erlotinib, ketoconazole, itraconazole, ledipasvir/sofosbuvir, nilotinib, and rilpivirine.
Famotidine Also Interacts With
- Theophylline major
- Tizanidine moderate
- Ledipasvir/Sofosbuvir minor
- Itraconazole minor
- Aripiprazole 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 Famotidine + 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 Famotidine's 11. In the minor band specifically: Famotidine has 9 (also Ledipasvir/Sofosbuvir, Itraconazole, Aripiprazole, Cidofovir); Ketoconazole has 85 (also Abiraterone, Acetaminophen/Oxycodone, Alosetron, Amphotericin B).
What mechanism field is on file for Famotidine and Ketoconazole?
Famotidine reduces stomach acid, which can prevent ketoconazole from being absorbed into your system.
Ketoconazole carries more major-labeled pairs than Famotidine
SPL source-record counts only. This page's band is minor · classes on file: Famotidine (H2 Receptor Antagonist); Ketoconazole (Azole Antifungal).
Ketoconazole has 6 major-labeled pairs vs Famotidine's 1. This page itself is in the minor band, not the major band.
1 major · 1 moderate · 9 minor · 11 total
- Other minor peers for Famotidine
- Ledipasvir/Sofosbuvir
- Itraconazole
- Aripiprazole
- Cidofovir
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.