What the FDA labels say about taking them together
Ibritumomab tiuxetan and rituximab
Ibritumomab tiuxetan's FDA label of April 25, 2023 names rituximab in its boxed warning section; the rituximab labels PlainMeds reads (4) do not name ibritumomab tiuxetan. The ibritumomab tiuxetan label: “… warning Serious Infusion Reactions, some fatal, may occur within 24 hours of rituximab infusion. Prolonged and Severe Cytopenias occur in most patients. …”
Check it at the source: the ibritumomab tiuxetan FDA label on DailyMed (effective April 25, 2023, Acrotech Biopharma Inc); the rituximab FDA label on DailyMed (effective January 6, 2025, Genentech, Inc.).
What does the ibritumomab tiuxetan label say about rituximab?
Ibritumomab tiuxetan label, boxed warningSERIOUS INFUSION REACTIONS, PROLONGED AND SEVERE CYTOPENIAS, and SEVERE CUTANEOUS AND MUCOCUTANEOUS REACTIONS See full prescribing information for complete boxed warning Serious Infusion Reactions, some fatal, may occur within 24 hours of rituximab infusion. ( 5.1 ) Prolonged and Severe Cytopenias occur in most patients. ( 5.2 ) Severe Cutaneous and Mucocutaneous Reactions, some fatal, reported with Zevalin therapeutic regimen. ( 5.3 , 6.2 ) Do not exceed 32 mCi (1184 MBq) of Y-90 Zevalin.
Ibritumomab tiuxetan label, warnings and precautionsWARNINGS AND PRECAUTIONS Serious Infusion Reactions: Immediately discontinue rituximab and Y-90 Zevalin. ( 5.1 , 6.1 ) Prolonged and Severe Cytopenias:
Source: FDA drug label (Zevalin), BLA125019 (Spectrum Pharms), as published by Acrotech Biopharma Inc, effective April 25, 2023 (SPL set 25d367dc-da65-44c9-a844-1bf15339c285), via openFDA; the full label on DailyMed
What does the rituximab label say about ibritumomab tiuxetan?
Rituximab's label (effective January 6, 2025) and its 3 other brand-application labels do not name ibritumomab tiuxetan in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Rituxan), Genentech, Inc., effective January 6, 2025 (SPL set b172773b-3905-4a1c-ad95-bab4b6126563), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Ibritumomab tiuxetan | Rituximab | |
|---|---|---|
| Labeled for | Leukemia, lymphoma and myeloma | Leukemia, lymphoma and myeloma, Rheumatoid arthritis |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | n/a |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once