Cimetidine and Hydroxychloroquine Interaction
Drug interaction information between Cimetidine and Hydroxychloroquine.
Cimetidine and Hydroxychloroquine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Cimetidine and Hydroxychloroquine. 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
Cimetidine can slow down how your body breaks down hydroxychloroquine, which can double the amount of the drug in your system. This makes side effects much more likely.
FDA Label Information
7.8 Cimetidine Concomitant use of cimetidine resulted in a 2-fold increase of exposure of chloroquine, which is structurally related to hydroxychloroquine. Interaction of cimetidine with hydroxychloroquine cannot be ruled out. Avoid concomitant use of cimetidine.
Cimetidine Also Interacts With
- Levofloxacin major
- Posaconazole major
- Risperidone major
- Valproate major
- Empagliflozin moderate
Hydroxychloroquine Also Interacts With
- Chloroquine moderate
- Heparin moderate
- Remdesivir moderate
- Methotrexate minor
- Cyclosporine minor
Frequently Asked Questions
What SPL severity band is on file for Cimetidine + Hydroxychloroquine?
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?
Cimetidine has 77 labeled pairs on file vs Hydroxychloroquine's 7. In the moderate band specifically: Cimetidine has 10 (also Empagliflozin, Empagliflozin/Linagliptin, Ertugliflozin, Linagliptin); Hydroxychloroquine has 4 (also Chloroquine, Heparin, Remdesivir).
What mechanism field is on file for Cimetidine and Hydroxychloroquine?
Cimetidine can slow down how your body breaks down hydroxychloroquine, which can double the amount of the drug in your system. This makes side effects much more likely.
Cimetidine carries more major-labeled pairs than Hydroxychloroquine
SPL source-record counts only. This page's band is moderate · classes on file: Cimetidine (H2 Receptor Antagonist); Hydroxychloroquine (Disease-Modifying Antirheumatic Drug (DMARD)).
Cimetidine has 4 major-labeled pairs vs Hydroxychloroquine's 0. This page itself is in the moderate band, not the major band.
4 major · 10 moderate · 63 minor · 77 total
- Other moderate peers for Cimetidine
- Empagliflozin
- Empagliflozin/Linagliptin
- Ertugliflozin
- Linagliptin
0 major · 4 moderate · 3 minor · 7 total
- Other moderate peers for Hydroxychloroquine
- Chloroquine
- Heparin
- Remdesivir
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.