Nafcillin Injection and Pacritinib: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nafcillin Injection
Pacritinib
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
Reduce pacritinib exposure and risk of impaired efficacy
Interaction Deep Dive
Avoid coadministration of pacritinib with a moderate CYP3A4 inducer. Although not studied in vivo, concurrent use may cause a significant decrease in pacritinib exposure and risk for reduced efficacy may result, based on clinical study of coadministration of pacritinib with a strong CYP3A4 inducer1.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of pacritinib
Literature reports
1 report — tap to read
a) Although not studied in vivo, concurrent use may cause a significant decrease in pacritinib exposure and risk for reduced efficacy may result, based on clinical study of coadministration of pacritinib with a strong CYP3A4 inducer 1.
Common questions
Can I take Nafcillin Injection and Pacritinib together?
Reduce pacritinib exposure and risk of impaired efficacy Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nafcillin Injection and Pacritinib 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Nafcillin Injection or Pacritinib 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 (1)
- Product Information: VONJO(TM) oral capsules, pacritinib oral capsules. CTI BioPharma Corp (per FDA), Seattle, WA, 2022. DailyMed
Keep reading about Nafcillin Injection
Keep reading about Pacritinib
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.
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