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Omalizumab Side Effects

The most commonly reported side effects of omalizumab include asthma, no adverse event, and urticaria, based on 79,895 FDA adverse event reports from 2004 to 2025. 9.5% of reports found the drug to be ineffective.

Omalizumab side effects

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

1
Asthma13.4%10,701
2
No Adverse Event12.8%10,202
3
Urticaria12.6%10,100
4
Off Label Use12.4%9,929
5
Dyspnoea11.6%9,297
6
Drug Ineffective9.5%7,621
7
Cough8.2%6,544
8
Pruritus7.2%5,732
9
Fatigue7.0%5,623
10
Malaise6.6%5,286
11
Wheezing6.2%4,992
12
Headache6.2%4,934
13
Pneumonia6.0%4,801
14
Pain5.0%4,018
15
Nasopharyngitis4.7%3,745

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

Report severity

53.5%Serious42,751 reports
19.0%Hospitalizations15,168 reports
3.0%Fatal2,391 reports

Seriousness is determined by the reporter, not by OpenClaim.

Omalizumab drug interactions

Other drugs that appear in adverse event reports alongside omalizumab. 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
Montelukast-sodium5.3%4,241
2
Prednisone4.0%3,210
3
Albuterol2.5%1,983
4
Fluticasone2.0%1,607
5
Budesonide1.9%1,520
6
Clonazepam1.8%1,416
7
Dupilumab1.7%1,340
8
Rosuvastatin1.6%1,240
9
Tiotropium-bromide1.5%1,200
10
Mepolizumab1.5%1,187
11
Amlodipine1.5%1,163
12
Formoterol1.3%1,052
13
Rituximab1.3%1,021
14
Salmeterol-xinafoate1.2%973
15
Risedronate-sodium1.2%950

Taken alongside

1
Albuterol14.4%11,479
2
Montelukast-sodium14.2%11,336
3
Fluticasone9.9%7,935
4
Prednisone9.5%7,581
5
Budesonide8.2%6,512
6
Formoterol7.1%5,711
7
Cetirizine-hydrochloride6.6%5,273
8
Salmeterol-xinafoate6.4%5,119
9
Tiotropium-bromide5.6%4,441
10
Epinephrine3.9%3,099
11
Diphenhydramine3.7%2,925
12
Levothyroxine-sodium3.1%2,483
13
Fexofenadine-hydrochloride3.1%2,437
14
Mometasone-furoate3.0%2,432
15
Hydroxyzine2.8%2,224

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 omalizumab side effects

66.1% of omalizumab adverse event reports involve female patients and 23.8% involve male patients. The largest age group is adult at 70%. These figures reflect who reports side effects, not underlying risk.

Sex

Female66.1%
Male23.8%
Unknown10.1%

Age group

< 20.4%
2–112.7%
12–174.5%
18–6470.3%
65+22.1%

What is omalizumab used for

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

Accidental ExposureAcromegalyAcute Respiratory FailureAcute SinusitisAdenomatous Polyposis ColiAdrenal InsufficiencyAdverse EventAllergic BronchitisAllergic Bronchopulmonary MycosisAllergic ColitisAllergic EosinophiliaAllergic GastroenteritisAllergic Granulomatous AngiitisAllergic KeratitisAllergic Respiratory Disease

Showing 15 of 875 indications

Omalizumab brand names and reporting trend

Omalizumab is sold under the brand name Xolair.

Brand names

Xolair42,184

Quarterly reports (20042025)

20052010201520202025

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

Taking omalizumab with another medication?

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