Remdesivir and Chloroquine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Chloroquine
Remdesivir
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced antiviral activity of remdesivir
Interaction Deep Dive
The antiviral activity of remdesivir was reduced by chloroquine phosphate in a dose-dependent manner in Hep-2 cells with respiratory syncytial virus when co-incubated at clinically relevant concentrations. Higher remdesivir EC(50) values were observed with increasing concentrations of chloroquine phosphate. Chloroquine phosphate reduced remdesivir triphosphate in human bronchial epithelial cells. Concurrent use of remdesivir and chloroquine is not recommended1.
Why it happens (mechanism)
Antagonistic effect of chloroquine on metabolic activation of remdesivir
Common questions
Can I take Remdesivir and Chloroquine together?
Reduced antiviral activity of remdesivir Always confirm with your pharmacist or prescriber before making any change.
How serious is the Remdesivir and Chloroquine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Remdesivir or Chloroquine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: VEKLURY(R) intravenous injection, remdesivir intravenous injection. Gilead Sciences Inc (per FDA), Foster City, CA, 2024. DailyMed
Keep reading about Chloroquine
Keep reading about Remdesivir
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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