Rituximab vs Rituximab-Abbs: side effects in FDA adverse event reports
At a glance
| Rituximab | Rituximab-Abbs | |
|---|---|---|
| Drug class | CD20-directed Cytolytic Antibody | CD20-directed Cytolytic Antibody |
| Brand names | Rituxan | Truxima |
| FAERS reports | 210,132 | 4,946 |
| Serious | 89% | 73% |
| Death outcome | 37,069 | 516 |
| Boxed warning | Yes FATAL INFUSION-RELATED REACTIONS, SEVERE MUCOCUTANEOUS REACTIONS, HEPATITIS B VIRUS REACTIVATION and PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY WARNING: FATAL I | Yes FATAL INFUSION-RELATED REACTIONS, SEVERE MUCOCUTANEOUS REACTIONS, HEPATITIS B VIRUS REACTIVATION and PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY (PML) WARNING: F |
Signals both drugs share
| Reaction | Rituximab | Rituximab-Abbs | Label screen (A / B) |
|---|---|---|---|
| Pemphigus | 9,375 · PRR 315.6 | 130 · PRR 44.8 | Likely indication confounding / Likely indication confounding |
| Synovitis | 8,767 · PRR 94.5 | 129 · PRR 30.5 | Not in label — unassessed / Not in label — unassessed |
| Hand deformity | 7,685 · PRR 143.3 | 122 · PRR 39.9 | Not in label — unassessed / Not in label — unassessed |
| Helicobacter infection | 5,074 · PRR 99.1 | 132 · PRR 55.6 | Not in label — unassessed / Not in label — unassessed |
| Folliculitis | 4,291 · PRR 70.8 | 81 · PRR 33.5 | Likely indication confounding / Likely indication confounding |
Labeled signals distinctive to Rituximab
- Duodenal ulcer perforation — n=4,935, PRR 208.1 Labeled — boxed warning
- Rheumatic fever — n=3,199, PRR 280.1 Labeled (related wording)
- Sleep disorder due to general medical condition, insomnia type — n=2,715, PRR 72.7 Labeled (related wording)
- Peripheral venous disease — n=1,611, PRR 67.4 Labeled (related wording)
- Diffuse large b-cell lymphoma recurrent — n=1,437, PRR 205.1 Labeled (related wording)
- Lupus vulgaris — n=827, PRR 231.6 Labeled (related wording)
- Granuloma skin — n=507, PRR 158.9 Labeled (related wording)
- Follicular lymphoma — n=383, PRR 81.3 Labeled adverse reaction
Labeled signals distinctive to Rituximab-Abbs
- Infusion related reaction — n=237, PRR 15.3 Labeled — boxed warning
- Systemic lupus erythematosus — n=156, PRR 18.8 Labeled (related wording)
- Type 2 diabetes mellitus — n=81, PRR 10.2 Labeled (related wording)
- Autoimmune disorder — n=47, PRR 20.9 Labeled (related wording)
Common questions
Which has more reported side effects, Rituximab or Rituximab-Abbs?
Rituximab has 210,132 FAERS reports and Rituximab-Abbs 4,946. More reports does not mean more dangerous: volume follows how widely and how long a drug has been used, prescription vs over-the-counter status, and publicity. The seriousness share (89% vs 73%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Rituximab and Rituximab-Abbs share?
Both drugs carry disproportionality signals for pemphigus, synovitis, hand deformity, helicobacter infection, folliculitis. Shared signals often reflect a shared drug class or the condition both are used for.
Is Rituximab or Rituximab-Abbs safer?
FAERS cannot answer that: it has no denominator and no comparator. Use this page to see which risks are already on each label and which signals are unlabeled, then check the prescribing information and your clinician for your situation.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, openFDA count queries for seriousness and deaths. Pair chosen because it is a commonly searched comparison. Generated 2026-10-08.