Drug side effects
benralizumab Side Effects
The reactions most often reported to the FDA for benralizumab (also sold as Fasenra), with demographics, serious outcomes, and reporting trends.
Data updated 2026-05-15
- 17,680
- FAERS reports
Data from the FDA Adverse Event Reporting System (FAERS), 2012 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.
The most commonly reported side effects of benralizumab come from 17,680 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.
This page analyzes 17,680 reports to the FDA Adverse Event Reporting System (FAERS) for benralizumab (Fasenra): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.
Total Reports
17,680
Reports Mentioning Death
1,749
9.9% of reports — not proof the medicine caused the death
Hospitalizations
4,130
23.4% 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 1,749 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 1,434 |
| PNEUMONIA | 45 |
| ASTHMA | 42 |
| COVID-19 | 26 |
| RESPIRATORY FAILURE | 22 |
| DYSPNOEA | 20 |
| CARDIAC ARREST | 19 |
| MYOCARDIAL INFARCTION | 16 |
| FALL | 13 |
| ABORTION SPONTANEOUS | 12 |
| CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 12 |
| EPILEPSY | 12 |
| GENERAL PHYSICAL HEALTH DETERIORATION | 12 |
| INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION | 11 |
| LUNG DISORDER | 11 |
| CARDIAC FAILURE | 10 |
| MALAISE | 9 |
Reactions in Hospitalization Reports
Top reactions in 4,130 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| ASTHMA | 1,048 |
| DYSPNOEA | 536 |
| PNEUMONIA | 464 |
| COUGH | 217 |
| WHEEZING | 180 |
| COVID-19 | 175 |
| PYREXIA | 172 |
| INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION | 171 |
| MALAISE | 170 |
| FALL | 157 |
| HEADACHE | 145 |
| FATIGUE | 126 |
| ILLNESS | 123 |
| INFLUENZA | 116 |
| ASTHENIA | 103 |
| PAIN | 103 |
| CHRONIC OBSTRUCTIVE PULMONARY DISEASE | 102 |
| INFECTION | 98 |
Nearby, Related Medications
What the FAERS Data Reveals About benralizumab Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 17,680 voluntary reports linked to benralizumab and its brand equivalents (Fasenra), spanning 2012 through 2025. Of those, 1,749 (9.9%) listed death as an outcome and 4,130 (23.4%) 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, 70% were female and 30% male; age distribution skews toward 45-64, with 1,909 reports in that bracket. The single most reported reaction is asthma with 2,775 submissions, followed by dyspnoea and death.
How to read these numbers
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.
Drugs With a Similar FAERS Report Volume
Other medications with a total FDA adverse-event report count closest to benralizumab's 17,680.
Read our methodology - how this data is sourced, computed, and verified.