omalizumab Side Effects
Also known as: Xolair
Analysis of 79,748 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
79,748
Death-Related
2,390
3.0% of reports
Hospitalizations
15,129
19.0% of reports
Top Indication
Asthma
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 2,390 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 1,455 |
| ASTHMA | 301 |
| PNEUMONIA | 179 |
| DYSPNOEA | 165 |
| MALAISE | 129 |
| FATIGUE | 111 |
| OFF LABEL USE | 105 |
| ASTHENIA | 101 |
| COUGH | 99 |
| MYOCARDIAL INFARCTION | 86 |
| WHEEZING | 85 |
| HEART RATE INCREASED | 81 |
| WEIGHT DECREASED | 81 |
| DRUG INEFFECTIVE | 75 |
| CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 67 |
| FALL | 67 |
| FORCED EXPIRATORY VOLUME DECREASED | 63 |
| LUNG DISORDER | 61 |
| HEADACHE | 60 |
| RESPIRATORY FAILURE | 59 |
Reactions in Hospitalization Reports
Top reactions in 15,129 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| ASTHMA | 5,346 |
| DYSPNOEA | 4,226 |
| COUGH | 3,043 |
| PNEUMONIA | 2,699 |
| MALAISE | 2,262 |
| WHEEZING | 2,208 |
| FATIGUE | 2,039 |
| URTICARIA | 1,872 |
| HEADACHE | 1,727 |
| DRUG INEFFECTIVE | 1,707 |
| WEIGHT DECREASED | 1,613 |
| NASOPHARYNGITIS | 1,605 |
| PYREXIA | 1,573 |
| PRURITUS | 1,338 |
| PAIN | 1,320 |
| CHEST DISCOMFORT | 1,313 |
| INFLUENZA | 1,307 |
| PRODUCTIVE COUGH | 1,285 |
| BLOOD PRESSURE INCREASED | 1,234 |
| HYPERSENSITIVITY | 1,216 |
Nearby — Related Medications
What the FAERS Data Reveals About omalizumab Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 79,748 voluntary reports linked to omalizumab and its brand equivalents (Xolair), spanning 2004 through 2025. Of those, 2,390 (3.0%) listed death as an outcome and 15,129 (19.0%) involved hospitalization. The most common indication reported alongside adverse events was Asthma.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 73% were female and 26% male; age distribution skews toward 45-64, with 15,541 reports in that bracket. The single most reported reaction is asthma with 11,601 submissions, followed by urticaria and no adverse event.
FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice — speak with a licensed clinician about any side-effect concerns.
Read our methodology — how this data is sourced, computed, and verified.