Sulfinpyrazone and Cyclosporine Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Sulfinpyrazone
No brand names on recordCyclosporine Injection
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 cycloSPORINE exposure and an increased risk of organ rejection
Interaction Deep Dive
Concomitant use of cycloSPORINE and sulfinpyrazone may decrease cycloSPORINE levels. Adjust cycloSPORINE dosage to achieve the desired cycloSPORINE concentrations when these drugs are administered concomitantly12. In a retrospective study of heart transplant patients, cycloSPORINE (CsA) levels decreased upon concurrent administration of sulfinpyrazone, including unexpected acute rejection occurring in 2 patients. While the exact mechanism for this interaction has not been studied, cytochrome P450-mediated induction of CsA metabolism by sulfinpyrazone is believed to be the cause. Due to the risk of organ rejection and until further studies are conducted, sulfinpyrazone should not be administered routinely in combination with cycloSPORINE 3.
Why it happens (mechanism)
Increased cycloSPORINE metabolism by sulfinpyrazone
Literature reports
1 report — tap to read
a) In a retrospective study of heart transplant patients, cycloSPORINE (CsA) levels decreased upon addition of sulfinpyrazone. Heart transplant recipients (n=120) were on either a double therapy (n=56) of CsA and azaTHIOprine (Aza) or on a triple therapy (n=64) of CsA, Aza, and oral predniSONE. Additionally all patients were on allopurinol for at least 6 months for history of gout and/or hyperuricemia with mild renal dysfunction. Allopurinol was discontinued 1 month prior to initiation of sulfinpyrazone which was administered as a daily oral dose of 200 milligrams (mg) for approximately 6 months. At the end of the treatment period, mean uricemia reduction achieved with sulfinpyrazone was comparable to that obtained with allopurinol treatment. However, with sulfinpyrazone treatment, CsA levels dropped from 183 +/- 89 nanograms/milliliter (ng/mL) to 121 +/- 63 ng/mL (p=0.0001) despite an increase in CsA daily dose. Results were similar for patients on either double or triple immunosuppressant therapy, although mean CsA daily dose at the end of sulfinpyrazone treatment was higher for patients on triple therapy. Unexpected late acute rejection occurred in 2 patients, both on triple therapy. Although the exact mechanism for this reduction in CsA levels is not known and further studies are warranted, the investigators propose that cytochrome P450-mediated induction of CsA metabolism by sulfinpyrazone may be partly responsible 3.
Common questions
Can I take Sulfinpyrazone and Cyclosporine Injection together?
Reduced cycloSPORINE exposure and an increased risk of organ rejection Always confirm with your pharmacist or prescriber before making any change.
How serious is the Sulfinpyrazone and Cyclosporine Injection 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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Sulfinpyrazone or Cyclosporine Injection 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 (3)
- Product Information: NEORAL(R) oral soft gelatin capsules oral solution, cyclosporine modified oral soft gelatin capsules oral solution. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Product Information: SANDIMMUNE(R) oral capsules, oral solution, intravenous injection, cyclosporine oral capsules, oral solution, intravenous injection. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Caforio ALP, Gambino A, Tona F, et al: Sulfinpyrazone reduces cyclosporine levels: a new drug interaction in heart transplant recipients. J Heart Lung Transplant 2000; 19:1205-1208. PubMed
Keep reading about Sulfinpyrazone
Keep reading about Cyclosporine Injection
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.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist