Rituximab vs Natalizumab: side effects in FDA adverse event reports
At a glance
| Rituximab | Natalizumab | |
|---|---|---|
| Drug class | CD20-directed Cytolytic Antibody | Integrin Receptor Antagonist |
| Brand names | Rituxan | Tysabri |
| FAERS reports | 210,132 | 180,630 |
| Serious | 89% | 31% |
| Death outcome | 37,069 | 5,103 |
| Boxed warning | Yes FATAL INFUSION-RELATED REACTIONS, SEVERE MUCOCUTANEOUS REACTIONS, HEPATITIS B VIRUS REACTIVATION and PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY WARNING: FATAL I | Yes PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY TYSABRI increases the risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of t |
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 Natalizumab
- Multiple sclerosis relapse — n=16,902, PRR 37.4 Labeled (related wording)
- General symptom — n=2,192, PRR 47.4 Labeled (related wording)
- Progressive multifocal leukoencephalopathy — n=2,127, PRR 40.1 Labeled — boxed warning
- Musculoskeletal disorder — n=1,750, PRR 11.6 Labeled (related wording)
- Central nervous system lesion — n=1,674, PRR 15.9 Labeled (related wording)
- Coordination abnormal — n=1,227, PRR 11.0 Labeled (related wording)
- Immune reconstitution inflammatory syndrome — n=1,182, PRR 35.7 Labeled adverse reaction
- Opportunistic infection — n=494, PRR 42.0 Labeled adverse reaction
Common questions
Which has more reported side effects, Rituximab or Natalizumab?
Rituximab has 210,132 FAERS reports and Natalizumab 180,630. 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 31%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Rituximab and Natalizumab share?
They share no strong flagged signal after artifacts and lab terms are removed.
Is Rituximab or Natalizumab 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.