Hydroxychloroquine and Chloroquine Interaction
Drug interaction information between Hydroxychloroquine and Chloroquine.
Hydroxychloroquine and Chloroquine have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Hydroxychloroquine and Chloroquine. 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
Both of these drugs can change the electrical rhythm of your heart. Taking them together increases the risk of a dangerous irregular heartbeat.
What To Do
This combination is not recommended. Talk to your doctor about using a different medication to avoid heart rhythm problems.
FDA Label Information
( 7 ) 7.1 Drugs Prolonging QT Interval and Other Arrhythmogenic Drugs Hydroxychloroquine sulfate tablets prolongs the QT interval. There may be an increased risk of inducing ventricular arrhythmias if hydroxychloroquine sulfate tablets are used concomitantly with other arrhythmogenic drugs. Therefore, hydroxychloroquine sulfate tablets are not recommended in patients taking other drugs that have the potential to prolong the QT interval or are arrhythmogenic [see Warnings and Precautions (5.1) ].
Hydroxychloroquine Also Interacts With
- Cimetidine moderate
- Heparin moderate
- Remdesivir moderate
- Methotrexate minor
- Cyclosporine minor
Chloroquine Also Interacts With
- Dapsone Topical moderate
- Lidocaine Topical moderate
- Remdesivir moderate
- Methylprednisolone minor
Frequently Asked Questions
Can I take Hydroxychloroquine and Chloroquine together?
This is a moderate interaction. This combination is not recommended. Talk to your doctor about using a different medication to avoid heart rhythm problems.
How serious is the interaction between Hydroxychloroquine and Chloroquine?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Hydroxychloroquine and Chloroquine interact?
Both of these drugs can change the electrical rhythm of your heart. Taking them together increases the risk of a dangerous irregular heartbeat.
Understanding the Hydroxychloroquine and Chloroquine Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Hydroxychloroquine belongs to the Disease-Modifying Antirheumatic Drug (DMARD) class and Chloroquine belongs to the Antimalarial class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both of these drugs can change the electrical rhythm of your heart. 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. Hydroxychloroquine has 7 total documented interactions on file in this dataset, and Chloroquine has 5. 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: This combination is not recommended. 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 Hydroxychloroquine or Chloroquine 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.