Rituximab vs Cyclophosphamide For: side effects in FDA adverse event reports
At a glance
| Rituximab | Cyclophosphamide For | |
|---|---|---|
| Drug class | CD20-directed Cytolytic Antibody | – |
| Brand names | Rituxan | Cyclophosphamide |
| FAERS reports | 210,132 | 175,993 |
| Serious | 89% | 96% |
| Death outcome | 37,069 | 35,641 |
| Boxed warning | Yes FATAL INFUSION-RELATED REACTIONS, SEVERE MUCOCUTANEOUS REACTIONS, HEPATITIS B VIRUS REACTIVATION and PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY WARNING: FATAL I | No |
Signals both drugs share
| Reaction | Rituximab | Cyclophosphamide For | Label screen (A / B) |
|---|---|---|---|
| Diffuse large b-cell lymphoma recurrent | 1,437 · PRR 205.1 | 1,247 · PRR 166.5 | Labeled (related wording) / Likely indication confounding |
| Follicular lymphoma | 383 · PRR 81.3 | 256 · PRR 50.9 | Labeled adverse reaction / Likely indication confounding |
| Diffuse large b-cell lymphoma refractory | 450 · PRR 93.7 | 391 · PRR 86.5 | Likely indication confounding / Likely indication confounding |
| B-cell lymphoma recurrent | 325 · PRR 150.8 | 230 · PRR 87.9 | Likely indication confounding / Likely indication confounding |
| Mantle cell lymphoma recurrent | 263 · PRR 160.2 | 190 · PRR 95.1 | Likely indication confounding / Likely indication confounding |
| Lymphoma transformation | 212 · PRR 143.5 | 94 · PRR 41.8 | 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)
- Lupus vulgaris — n=827, PRR 231.6 Labeled (related wording)
- Granuloma skin — n=507, PRR 158.9 Labeled (related wording)
Labeled signals distinctive to Cyclophosphamide For
- Cytomegalovirus infection reactivation — n=1,352, PRR 55.1 Labeled (related wording)
- Cystitis haemorrhagic — n=1,125, PRR 46.1 Labeled (related wording)
- Hepatitis b reactivation — n=791, PRR 39.3 Labeled (related wording)
- Viral haemorrhagic cystitis — n=284, PRR 80.2 Labeled (related wording)
- Secondary immunodeficiency — n=283, PRR 36.8 Labeled (related wording)
- Cystitis viral — n=177, PRR 103.7 Labeled (related wording)
- Ovarian failure — n=143, PRR 42.7 Labeled adverse reaction
- Cystitis bacterial — n=100, PRR 49.4 Labeled (related wording)
Common questions
Which has more reported side effects, Rituximab or Cyclophosphamide For?
Rituximab has 210,132 FAERS reports and Cyclophosphamide For 175,993. 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 96%) is a better like-for-like signal of the kind of problems reported.
Which side effects do Rituximab and Cyclophosphamide For share?
Both drugs carry disproportionality signals for diffuse large b-cell lymphoma recurrent, follicular lymphoma, diffuse large b-cell lymphoma refractory, b-cell lymphoma recurrent, mantle cell lymphoma recurrent. Shared signals often reflect a shared drug class or the condition both are used for.
Is Rituximab or Cyclophosphamide For 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.