baloxavir marboxil Side Effects
Also known as: Xofluza
Analysis of 2,164 adverse event reports submitted to the FDA from 2017 to 2025.
Total Reports
2,164
Death-Related
130
6.0% of reports
Hospitalizations
417
19.3% of reports
Top Indication
Influenza
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 130 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 32 |
| PNEUMONIA | 18 |
| INFLUENZA | 10 |
| RESPIRATORY FAILURE | 9 |
| CARDIO-RESPIRATORY ARREST | 7 |
| MULTIPLE ORGAN DYSFUNCTION SYNDROME | 7 |
| ACUTE KIDNEY INJURY | 6 |
| DRUG INEFFECTIVE | 6 |
| OFF LABEL USE | 6 |
| ACUTE RESPIRATORY DISTRESS SYNDROME | 5 |
| DISSEMINATED INTRAVASCULAR COAGULATION | 5 |
| INFECTION | 5 |
| SEPSIS | 5 |
| CARDIAC FAILURE | 4 |
| DECREASED APPETITE | 4 |
| PNEUMONIA INFLUENZAL | 4 |
| ACUTE RESPIRATORY FAILURE | 3 |
| ALANINE AMINOTRANSFERASE INCREASED | 3 |
| BRAIN HERNIATION | 3 |
| CIRCULATORY COLLAPSE | 3 |
Reactions in Hospitalization Reports
Top reactions in 417 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| PNEUMONIA | 52 |
| DIARRHOEA | 29 |
| COLITIS ISCHAEMIC | 25 |
| VOMITING | 24 |
| RHABDOMYOLYSIS | 17 |
| OFF LABEL USE | 16 |
| ANAPHYLACTIC REACTION | 14 |
| PYREXIA | 13 |
| ABDOMINAL PAIN | 12 |
| DRUG ERUPTION | 12 |
| ABNORMAL BEHAVIOUR | 11 |
| ACUTE KIDNEY INJURY | 11 |
| DECREASED APPETITE | 11 |
| DRUG INEFFECTIVE | 11 |
| HEPATIC FUNCTION ABNORMAL | 11 |
| RASH | 11 |
| SEIZURE | 11 |
| DYSPNOEA | 10 |
| SEPSIS | 10 |
| HAEMATOCHEZIA | 9 |
Nearby — Related Medications
What the FAERS Data Reveals About baloxavir marboxil Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 2,164 voluntary reports linked to baloxavir marboxil and its brand equivalents (Xofluza), spanning 2017 through 2025. Of those, 130 (6.0%) listed death as an outcome and 417 (19.3%) involved hospitalization. The most common indication reported alongside adverse events was Influenza.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 54% were female and 46% male; age distribution skews toward 0-17, with 619 reports in that bracket. The single most reported reaction is no adverse event with 518 submissions, followed by off label use and intentional product use issue.
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.