Busulfan Injection and Blinatumomab: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Busulfan Injection
Blinatumomab
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
Increased busulfan exposure
Interaction Deep Dive
Blinatumomab causes a transient elevation of cytokines which may suppress CYP450 enzyme activities and result in increased exposure of CYP450 substrates, especially those with a narrow therapeutic index. Risk of interaction is increased during the first 9 days of the first cycle of blinatumomab and the first 2 days of the second cycle1. In a case report, administration of blinatumomab followed 48-hours later with busulfan resulted in a decrease in busulfan clearance necessitating a 31% lower dosage requirement to achieve the target AUC 2. Patients coadministered blinatumomab and CYP450 substrates should be monitored for toxicity or drug concentrations. Dosage of the substrate should be adjusted as needed 1.
Why it happens (mechanism)
Transient elevation of cytokines by blinatumomab may suppress CYP450-mediated metabolism of busulfan
Literature reports
1 report — tap to read
a) In a 35-year-old man with relapsed Philadelphia-like acute lymphoblastic leukemia, administration of blinatumomab followed 48-hours later with busulfan required a decreased busulfan dosage of 0.8 mg/kg to attain the target AUC of 4800 mcmol x min/dose. A test dose analysis demonstrated a delay in busulfan clearance resulting in a recommended dose of 9.92 mg/kg to achieve the target AUC. In repeat pharmacokinetic testing 2 weeks later, the busulfan clearance increased from 2.16 to 3.02 mL/min/kg, therefore the calculated dose was 12.96 mg/kg (31% greater) 2.
Common questions
Can I take Busulfan Injection and Blinatumomab together?
Increased busulfan exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Busulfan Injection and Blinatumomab interaction?
It is rated major. Potentially serious — often needs a change or close 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 Busulfan Injection or Blinatumomab 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 (2)
Keep reading about Busulfan Injection
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