Irinotecan Injection and Smallpox Monkeypox Vaccine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Irinotecan Injection
Smallpox Monkeypox Vaccine
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 infection by the live vaccine
Interaction Deep Dive
Do not administer smallpox and monkeypox vaccine to individuals with severe immunodeficiency2. Patients with leukemia, lymphoma, or other malignancies whose disease is in remission, who have restored immunocompetence, and whose chemotherapy has been discontinued for at least 3 months can receive a live vaccine 1.
Why it happens (mechanism)
Decreased immune response allows live vaccine to produce infection
Common questions
Can I take Irinotecan Injection and Smallpox Monkeypox Vaccine together?
An increased risk of infection by the live vaccine Always confirm with your pharmacist or prescriber before making any change.
How serious is the Irinotecan Injection and Smallpox Monkeypox Vaccine interaction?
It is rated contraindicated. These should generally not be used together.
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 "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Irinotecan Injection or Smallpox Monkeypox Vaccine 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)
- Centers for Disease Control and Prevention (CDC): Vaccines & Immunizations: altered immunocompetence. Centers for Disease Control and Prevention (CDC). Atlanta, GA. 2024.
- Product Information: ACAM2000 percutaneous injection, smallpox and mpox (vaccinia) vaccine, live percutaneous injection. Emergent Product Development Gaithersburg Inc (per FDA), Gaithersburg, MD, 2024. DailyMed
Keep reading about Irinotecan Injection
Keep reading about Smallpox Monkeypox Vaccine
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