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Rituximab Side Effects

The most commonly reported side effects of rituximab include off label use, rheumatoid arthritis, and pain, based on 222,541 FDA adverse event reports from 2004 to 2025. 16.0% of reports found the drug to be ineffective.

Rituximab side effects

Percentages show how often each reaction appears relative to total reports for rituximab.

1
Off Label Use20.6%45,745
2
Drug Ineffective16.0%35,599
3
Rheumatoid Arthritis9.6%21,273
4
Pain8.3%18,395
5
Fatigue8.0%17,790
6
Arthralgia6.3%13,931
7
Rash6.1%13,570
8
Infusion Related Reaction5.8%12,971
9
Drug Intolerance5.8%12,901
10
Pneumonia5.6%12,497
11
Joint Swelling5.5%12,309
12
Nausea5.3%11,899
13
Pyrexia5.0%11,203
14
Alopecia4.9%10,989
15
Contraindicated Product Administered4.9%10,843

These are voluntary reports and do not establish that rituximab caused these reactions.

Report severity

89.0%Serious198,095 reports
31.7%Hospitalizations70,538 reports
16.7%Fatal37,247 reports

Seriousness is determined by the reporter, not by OpenClaim.

Rituximab drug interactions

Other drugs that appear in adverse event reports alongside rituximab. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Prednisone21.9%48,778
2
Cyclophosphamide20.6%45,811
3
Methotrexate20.0%44,530
4
Vincristine-sulfate17.4%38,741
5
Doxorubicin-hydrochloride16.4%36,446
6
Etanercept12.9%28,699
7
Adalimumab12.1%26,869
8
Tocilizumab11.9%26,501
9
Abatacept11.6%25,756
10
Leflunomide10.9%24,264
11
Hydroxychloroquine-sulfate10.8%24,069
12
Infliximab9.8%21,821
13
Sulfasalazine8.1%18,113
14
Prednisolone7.2%15,940
15
Golimumab6.6%14,794

Taken alongside

1
Acetaminophen14.4%32,019
2
Prednisone12.4%27,652
3
Methylprednisolone9.9%22,072
4
Diphenhydramine9.2%20,377
5
Methotrexate6.1%13,464
6
Pantoprazole-sodium5.9%13,052
7
Folic-acid4.6%10,271
8
Cyclophosphamide4.3%9,585
9
Hydroxychloroquine-sulfate4.1%9,059
10
Tofacitinib3.8%8,440
11
Levothyroxine-sodium3.7%8,305
12
Sulfamethoxazole3.6%8,085
13
Ergocalciferol3.4%7,618
14
Acyclovir3.4%7,548
15
Trimethoprim3.2%7,216

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports rituximab side effects

43.8% of rituximab adverse event reports involve female patients and 31.1% involve male patients. The largest age group is adult at 57%. These figures reflect who reports side effects, not underlying risk.

Sex

Female43.8%
Male31.1%
Unknown25.1%

Age group

< 20.9%
2–112.5%
12–172.0%
18–6457.1%
65+37.5%

What is rituximab used for

Conditions and purposes for which patients were taking rituximab when the adverse event was reported.

22q11.2 Deletion SyndromeAbdominal DistensionAbdominal LymphadenopathyAbdominal MassAbdominal NeoplasmAbo IncompatibilityAbo IncompatibilityAccidental ExposureAcquired Amegakaryocytic ThrombocytopeniaAcquired Antithrombin Iii DeficiencyAcquired Epidermolysis BullosaAcquired HaemophiliaAcquired Haemophilia With Anti Fviii, Xi, Or XiiiAcquired Von Willebrand^s DiseaseActivated Pi3 Kinase Delta Syndrome

Showing 15 of 3,133 indications

Rituximab brand names and reporting trend

Rituximab is sold under several brand names including Rituxan Hycela, Truxima, Ruxience.

Brand names

Rituxan Hycela289,798
Truxima277
Ruxience97
Riabni6

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking rituximab with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.