OpenClaim

Emicizumab Side Effects

The most commonly reported side effects of emicizumab include haemorrhage, no adverse event, and haemarthrosis, based on 11,166 FDA adverse event reports from 2009 to 2025. 1.8% of reports found the drug to be ineffective.

#1 Reported: HaemorrhageAll side effects ↓Top Co-Medication: RituximabDrug interactions ↓52% of Reports Are AdultDemographics ↓

Emicizumab side effects

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

1
Haemorrhage36.4%4,065
2
No Adverse Event6.8%754
3
Haemarthrosis6.6%740
4
Off Label Use6.5%726
5
Fall5.3%591
6
Arthralgia4.1%462
7
Contusion3.3%369
8
Epistaxis3.2%358
9
Head Injury2.8%313
10
Pain2.7%302
11
Muscle Haemorrhage2.5%282
12
Weight Increased1.9%217
13
Joint Injury1.9%209
14
Mouth Haemorrhage1.8%204
15
Limb Injury1.8%204

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

Report severity

36.4%Serious4,062 reports
15.1%Hospitalizations1,686 reports
3.1%Fatal347 reports

Seriousness is determined by the reporter, not by OpenClaim.

Emicizumab drug interactions

Other drugs that appear in adverse event reports alongside emicizumab. 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
Rituximab1.0%111
2
Estropipate0.3%35
3
Prednisolone0.3%31
4
Mycophenolate0.3%28
5
Cyclophosphamide0.2%24
6
Prednisone0.1%15
7
Cyclosporine<0.1%11
8
Venetoclax<0.1%10
9
Tranexamic-acid<0.1%9
10
Dexamethasone<0.1%9
11
Enoxaparin-sodium<0.1%8
12
Aspirin<0.1%6
13
Methylprednisolone<0.1%6
14
Clonidine<0.1%6
15
Gabapentin<0.1%6

Taken alongside

1
Acetaminophen1.4%159
2
Aminocaproic-acid1.2%139
3
Tranexamic-acid0.8%90
4
Sodium-chloride0.6%72
5
Celecoxib0.6%70
6
Amlodipine0.6%67
7
Tenofovir0.5%59
8
Dolutegravir0.5%57
9
Emtricitabine0.5%56
10
Prednisone0.5%55
11
Rituximab0.5%51
12
Prednisolone0.4%49
13
Estropipate0.4%47
14
Omeprazole0.4%41
15
Aspirin0.3%39

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 emicizumab side effects

3.5% of emicizumab adverse event reports involve female patients and 85.0% involve male patients. The largest age group is adult at 52%. These figures reflect who reports side effects, not underlying risk.

Sex

Female3.5%
Male85.0%
Unknown11.5%

Age group

< 24.4%
2–1122.4%
12–1712.9%
18–6451.9%
65+8.3%

What is emicizumab used for

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

Acquired HaemophiliaAcquired Von Willebrand^s DiseaseAutoimmune DisorderAcquired Von Willebrand^s DiseaseAcquired HaemophiliaAcute Respiratory FailureAnaemiaAnti Factor Viii Antibody IncreasedArthralgiaArthropathyAsymptomatic Hiv InfectionAutism Spectrum DisorderAutoimmune DisorderCoagulopathyCongenital Coagulopathy

Showing 15 of 110 indications

Emicizumab brand names and reporting trend

Emicizumab is sold under the brand name Hemlibra.

Brand names

Hemlibra1,283

Quarterly reports (2009–2025)

2009202020242025

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

Taking emicizumab with another medication?

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