Drug Interaction Report

Piperaquine and Cyclophosphamide: Interaction Details

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

Piperaquine

No brand names on record
+

Cyclophosphamide

Cytoxan® Frindovyx
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Moderate
Can be significant — usually manageable with 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 91 documented Piperaquine interactions, 13 are rated moderate — including this one.
Onset
unspecified
Evidence
theoretical
Severity
Moderate

What happens

Increased exposure of CYP2C19 substrates

Interaction Deep Dive

Concurrent administration of piperaquine (a CYP2C19 inhibitor) and a CYP2C19 substrate may increase the exposure of the CYP2C19 substrate. Due to the long half-life of piperaquine, caution is advised with administration of a CYP2C19 substrate for up to 3 months after discontinuation of piperaquine therapy1. If concomitant administration is required, use caution and monitor the patient closely.

Why it happens (mechanism)

Inhibition of CYP2C19-mediated metabolism by piperaquine

Common questions

Can I take Piperaquine and Cyclophosphamide together?

Increased exposure of CYP2C19 substrates Always confirm with your pharmacist or prescriber before making any change.

How serious is the Piperaquine and Cyclophosphamide 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Piperaquine or Cyclophosphamide 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)

  1. Product Information: Eurartesim oral film-coated tablets, piperaquine tetraphosphate dihydroartemisinin oral film-coated tablets. Sigma-Tau Industrie Farmaceutiche Riunite S.p.A (per EMA), Rome, Italy, 2012.
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Beyond drug–drug

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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.