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Belimumab Side Effects

The most commonly reported side effects of belimumab include product dose omission issue, systemic lupus erythematosus, and fatigue, based on 30,525 FDA adverse event reports from 2011 to 2025. 5.8% of reports found the drug to be ineffective.

Belimumab side effects

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

1
Product Dose Omission Issue15.9%4,840
2
Systemic Lupus Erythematosus12.2%3,730
3
Fatigue6.4%1,943
4
Drug Ineffective5.8%1,779
5
Pain5.5%1,689
6
Headache4.8%1,461
7
Wrong Technique In Device Usage Process4.7%1,430
8
Malaise4.5%1,383
9
Nausea4.5%1,361
10
Injection Site Pain4.4%1,328
11
Arthralgia4.2%1,293
12
Product Complaint3.9%1,181
13
Off Label Use3.4%1,044
14
Pyrexia3.1%932
15
Accidental Exposure To Product3.0%917

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

Report severity

42.3%Serious12,898 reports
14.7%Hospitalizations4,481 reports
2.9%Fatal895 reports

Seriousness is determined by the reporter, not by OpenClaim.

Belimumab drug interactions

Other drugs that appear in adverse event reports alongside belimumab. 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
Hydroxychloroquine-sulfate3.0%931
2
Mycophenolate3.0%907
3
Prednisone2.5%776
4
Methotrexate1.7%514
5
Azathioprine1.7%511
6
Rituximab1.4%434
7
Prednisolone1.2%374
8
Cyclophosphamide0.9%281
9
Tacrolimus0.7%226
10
Methylprednisolone0.7%204
11
Voclosporin0.6%183
12
Cyclosporine0.5%152
13
Acetaminophen0.5%149
14
Diphenhydramine0.3%93
15
Leflunomide0.3%82

Taken alongside

1
Hydroxychloroquine-sulfate10.4%3,171
2
Prednisone7.9%2,418
3
Mycophenolate3.6%1,093
4
Acetaminophen2.8%846
5
Methotrexate2.5%765
6
Ergocalciferol2.3%699
7
Azathioprine2.1%655
8
Levothyroxine-sodium2.0%623
9
Aspirin1.8%542
10
Gabapentin1.7%531
11
Folic-acid1.7%529
12
Omeprazole1.7%519
13
Prednisolone1.4%433
14
Methylprednisolone1.4%416
15
Duloxetine-hydrochloride1.3%408

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 belimumab side effects

76.7% of belimumab adverse event reports involve female patients and 5.6% involve male patients. The largest age group is adult at 87%. These figures reflect who reports side effects, not underlying risk.

Sex

Female76.7%
Male5.6%
Unknown17.7%

Age group

< 20.6%
2–110.2%
12–171.2%
18–6487.4%
65+10.6%

What is belimumab used for

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

Accidental ExposureAcute Cutaneous Lupus ErythematosusAlopeciaAnkylosing SpondylitisAntinuclear Antibody PositiveAntiphospholipid AntibodiesAntiphospholipid SyndromeArthralgiaArthritisArthropathyAsthmaAutoantibody PositiveAutoimmune DisorderAutoimmune Haemolytic AnaemiaAutoimmune Hepatitis

Showing 15 of 469 indications

Belimumab brand names and reporting trend

Belimumab is sold under the brand name Benlysta.

Brand names

Benlysta6,190

Quarterly reports (20112025)

20122016202020242025

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

Taking belimumab with another medication?

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