Hydroxychloroquine and Cimetidine Interaction
Drug interaction information between Hydroxychloroquine and Cimetidine.
Hydroxychloroquine and Cimetidine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Hydroxychloroquine and Cimetidine. 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.
Hydroxychloroquine Also Interacts With
- Chloroquine moderate
- Heparin moderate
- Remdesivir moderate
- Methotrexate minor
- Cyclosporine minor
Cimetidine Also Interacts With
- Levofloxacin major
- Posaconazole major
- Risperidone major
- Valproate major
- Empagliflozin moderate
Frequently Asked Questions
What SPL severity band is on file for Hydroxychloroquine + Cimetidine?
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: Hydroxychloroquine has 4 (also Chloroquine, Heparin, Remdesivir); Cimetidine has 10 (also Empagliflozin, Empagliflozin/Linagliptin, Ertugliflozin, Linagliptin).
What mechanism field is on file for Hydroxychloroquine and Cimetidine?
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: Hydroxychloroquine (Disease-Modifying Antirheumatic Drug (DMARD)); Cimetidine (H2 Receptor Antagonist).
Cimetidine has 4 major-labeled pairs vs Hydroxychloroquine's 0. This page itself is in the moderate band, not the major band.
0 major · 4 moderate · 3 minor · 7 total
- Other moderate peers for Hydroxychloroquine
- Chloroquine
- Heparin
- Remdesivir
4 major · 10 moderate · 63 minor · 77 total
- Other moderate peers for Cimetidine
- Empagliflozin
- Empagliflozin/Linagliptin
- Ertugliflozin
- Linagliptin
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.