Cyclophosphamide and Sparsentan: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cyclophosphamide
Sparsentan
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 CYP2B6 substrate exposure and reduced efficacy of CYP2B6 substrate
Interaction Deep Dive
Concomitant administration of sparsentan (CYP2B6 inducer) with CYP2B6 substrates may reduce the exposure of these substrates, which may reduce the efficacy related to these substrates. Monitor for efficacy of CYP2B6 substrates and consider dosage adjustment as required. In a study, concomitant use of sparsentan with buPROPion (CYP2B6 substrate) decreased the buPROPion Cmax by 32% and AUC by 33%1.
Why it happens (mechanism)
Induction of CYP2B6-substrate metabolism by sparsentan
Literature reports
1 report — tap to read
a) In a study, concomitant use of sparsentan (CYP2B6 inducer) with buPROPion (CYP2B6 substrate) decreased the buPROPion Cmax by 32% and AUC by 33% 1.
Common questions
Can I take Cyclophosphamide and Sparsentan together?
Reduced CYP2B6 substrate exposure and reduced efficacy of CYP2B6 substrate Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cyclophosphamide and Sparsentan interaction?
It is rated moderate. Can be significant — usually manageable with 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Cyclophosphamide or Sparsentan 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 (1)
- Product Information: FILSPARI® oral tablets, sparsentan oral tablets. Travere Therapeutics Inc, San Diego, CA, 2026. DailyMed
Keep reading about Cyclophosphamide
Keep reading about Sparsentan
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