anastrozole Side Effects
Also known as: Arimidex
Analysis of 35,161 adverse event reports submitted to the FDA from 2003 to 2025.
Total Reports
35,161
Death-Related
2,383
6.8% of reports
Hospitalizations
7,649
21.8% of reports
Top Indication
Breast Cancer
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 2,383 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 926 |
| DIARRHOEA | 347 |
| FATIGUE | 344 |
| DYSPNOEA | 333 |
| NAUSEA | 332 |
| VOMITING | 304 |
| ASCITES | 299 |
| FALL | 288 |
| ASTHENIA | 272 |
| ARTHRALGIA | 269 |
| DECREASED APPETITE | 269 |
| SEPSIS | 264 |
| HEADACHE | 257 |
| COUGH | 249 |
| DIZZINESS | 249 |
| ABDOMINAL PAIN | 247 |
| PRURITUS | 244 |
| CARDIO-RESPIRATORY ARREST | 243 |
| HAEMORRHAGIC STROKE | 241 |
| TACHYCARDIA | 241 |
Reactions in Hospitalization Reports
Top reactions in 7,649 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| NAUSEA | 703 |
| FATIGUE | 673 |
| DIARRHOEA | 633 |
| DYSPNOEA | 558 |
| VOMITING | 438 |
| ASTHENIA | 436 |
| FALL | 432 |
| ARTHRALGIA | 425 |
| PNEUMONIA | 417 |
| HEADACHE | 387 |
| PAIN | 383 |
| DIZZINESS | 372 |
| MALAISE | 353 |
| PYREXIA | 351 |
| ANAEMIA | 334 |
| WEIGHT DECREASED | 299 |
| OFF LABEL USE | 290 |
| DECREASED APPETITE | 272 |
| COUGH | 269 |
| HYPERTENSION | 260 |
Nearby — Related Medications
What the FAERS Data Reveals About anastrozole Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 35,161 voluntary reports linked to anastrozole and its brand equivalents (Arimidex), spanning 2003 through 2025. Of those, 2,383 (6.8%) listed death as an outcome and 7,649 (21.8%) involved hospitalization. The most common indication reported alongside adverse events was Breast Cancer.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 95% were female and 5% male; age distribution skews toward 45-64, with 9,987 reports in that bracket. The single most reported reaction is fatigue with 3,256 submissions, followed by arthralgia and nausea.
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.