Rituximab vs Omalizumab: side effects in FDA adverse event reports
At a glance
| Rituximab | Omalizumab | |
|---|---|---|
| Drug class | CD20-directed Cytolytic Antibody | Anti-IgE |
| Brand names | Rituxan | Xolair, Xolair Pfs |
| FAERS reports | 210,132 | 84,416 |
| Serious | 89% | 53% |
| Death outcome | 37,069 | 2,453 |
| Boxed warning | Yes FATAL INFUSION-RELATED REACTIONS, SEVERE MUCOCUTANEOUS REACTIONS, HEPATITIS B VIRUS REACTIVATION and PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY WARNING: FATAL I | Yes ANAPHYLAXIS Anaphylaxis presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue, has been reported to occur after |
Signals both drugs share
No strong shared signal after removing coding and lab terms.
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 Omalizumab
- Nasal oedema — n=375, PRR 65.4 Labeled (related wording)
- Smoke sensitivity — n=153, PRR 249.8 Labeled (related wording)
- Asthma-chronic obstructive pulmonary disease overlap syndrome — n=107, PRR 63.9 Labeled (related wording)
- Urinary tract discomfort — n=78, PRR 51.4 Labeled (related wording)
Common questions
Which has more reported side effects, Rituximab or Omalizumab?
Rituximab has 210,132 FAERS reports and Omalizumab 84,416. 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 53%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Rituximab and Omalizumab share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Rituximab or Omalizumab 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.