Chloroquine and Cyclosporine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cyclosporine
Chloroquine
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
An increased risk of cycloSPORINE toxicity (renal dysfunction, cholestasis, paresthesias)
Interaction Deep Dive
The introduction of chloroquine was followed by a sudden increase in the serum cycloSPORINE level in a 51-year-old patient. The patient also showed transient nephrotoxicity when cycloSPORINE levels were high1. A 28-year-old patient also experienced an increase in his cycloSPORINE level, blood pressure, and serum creatinine when chloroquine was twice introduced to his therapeutic regimen 2. Although the exact mechanism has not been determined, it is postulated that chloroquine may inhibit cycloSPORINE metabolism by direct enzyme inhibition or by enzyme competition 1.
Why it happens (mechanism)
Unknown
Literature reports
2 reports — tap to read
a) A 51-year-old male who underwent a living donor kidney transplant was receiving immunosuppressant therapy with cycloSPORINE 3.4 mg/kg, azathioprine 0.5 mg/kg, and prednisolone 17.5 mg daily. Because of a fever of unknown origin and recent travel to a malaria-endemic country, he was given a therapeutic trial of chloroquine without alteration of his immunosuppressant regimen. The cycloSPORINE level increased from a baseline value of 149 ng/mL to 420 ng/mL within 48 hours of initiating chloroquine treatment. Serum creatinine also increased from 95 mmol/L to 140 mmol/L. A week after the discontinuation of chloroquine, both the serum cycloSPORINE level and the serum creatinine value had returned to their previous baseline values 1.
b) Chloroquine 100 mg daily for six days caused an increase in the cycloSPORINE level of a 28-year-old male kidney transplant patient. His immunosuppression therapy consisted of prednisone 15 mg daily, cycloSPORINE 70 mg daily, and azathioprine 75 mg daily. Prior to chloroquine treatment, his cycloSPORINE concentration was 105 ng/mL, serum creatinine was 200 mmol/L, and his blood pressure was 130/80 mm Hg. Six days after the start of chloroquine, the patient's serum creatinine level was 234 mmol/L, serum cycloSPORINE was 470 ng/mL, and blood pressure had increased to 160/100 mm Hg. These values returned to normal after the discontinuation of chloroquine. The patient was rechallenged with chloroquine at the same dose one month later, and an increase in the serum cycloSPORINE level and hypertension again occurred 2.
Common questions
Can I take Chloroquine and Cyclosporine together?
An increased risk of cycloSPORINE toxicity (renal dysfunction, cholestasis, paresthesias) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Chloroquine and Cyclosporine interaction?
It is rated moderate. Can be significant — usually manageable with 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Chloroquine or Cyclosporine 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 anything you'd monitor while I'm on both?
References (2)
Keep reading about Cyclosporine
Keep reading about Chloroquine
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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