Drug Interaction Report

Chloroquine and Rabies Vaccine: Interaction Details

A pharmacist-reviewed analysis of the Chloroquine and Rabies Vaccine interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Rabies Vaccine

Imovax Imovax® RabAvert®
+

Chloroquine

Aralen®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 332 documented Chloroquine interactions, 294 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
delayed
Evidence
theoretical
Severity
Major

What happens

Decreased antibody response

Interaction Deep Dive

Depressed antibody response has been reported in patients who have been given rabies vaccine, human diploid cell (HDCV), intradermally when on concurrent chloroquine therapy123. It is recommended that persons on immunosuppressive therapy receive rabies vaccine by the intramuscular route until more definitive information is available 4.

Why it happens (mechanism)

Unknown

Common questions

Can I take Chloroquine and Rabies Vaccine together?

Decreased antibody response Always confirm with your pharmacist or prescriber before making any change.

How serious is the Chloroquine and Rabies Vaccine interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

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 Chloroquine or Rabies Vaccine 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 (4)

  1. Grabenstein JD: Drug interactions involving immunologic agents. Part I. Vaccine-vaccine, vaccine-immunoglobulin, and vaccine-drug interactions. DICP 1990; 24:67-81. DOI
  2. Anon: Rabies prevention - United States, 1991. Recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR 1991; 40:1-19. DOI
  3. Taylor DN, Wasi C, & Bernard K: Chloroquine prophylaxis associated with a poor antibody response to human diploid cell rabies vaccine. Lancet 1984; 1:1405. PubMed
  4. Product Information: Imovax(R) Rabies, rabies vaccine. Connaught Laboratories, Inc. Swiftwater, PA, 1991. DailyMed
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Rabies Vaccine

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Beyond drug–drug

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:

Chloroquine + Activated Charcoal Hibiscus Sabdariffa Biofeedback Coffee Charcoal Dendrobium European Mandrake Fever Bark Ginkgo + 21 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.