Pentostatin Injection and Fludarabine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 9, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Pentostatin Injection
Fludarabine
No brand names on record
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 severe and fatal pulmonary toxicity
Interaction Deep Dive
Avoid use of fludarabine in combination with pentostatin2 due to the risk of severe pulmonary toxicity 3. In a drug interaction study, concurrent use of pentostatin and fludarabine at the recommended dose in 6 patients with refractory chronic lymphocytic leukemia resulted in 4 of the 6 patients suffering severe or fatal pulmonary toxicity 1.
Why it happens (mechanism)
Unknown
Literature reports
1 report — tap to read
a) In a drug interaction study, concurrent use of pentostatin and fludarabine at the recommended dose in 6 patients with refractory chronic lymphocytic leukemia resulted in 4 of the 6 patients suffering severe or fatal pulmonary toxicity 1.
Common questions
Can I take Pentostatin Injection and Fludarabine together?
An increased risk of severe and fatal pulmonary toxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Pentostatin Injection and Fludarabine 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 "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Pentostatin Injection or Fludarabine 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: NIPENT(TM) intravenous injection, pentostatin intravenous injection. Hospira, Inc. (per manufacturer), Lake Forest, IL, 2015. DailyMed
- Product Information: FLUDARABINE PHOSPHATE intravenous injection, fludarabine phosphate intravenous injection. Sandoz (per FDA), Princeton, NJ, 2024. DailyMed
- Product Information: Fludara(R) IV injection, fludarabine phosphate IV injection. Genzyme Corporation, Cambridge, MA, 2010.
Keep reading about Pentostatin Injection
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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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