tamsulosin Side Effects
Also known as: Flomax
Analysis of 18,628 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
18,628
Death-Related
2,065
11.1% of reports
Hospitalizations
6,635
35.6% of reports
Top Indication
Product Used For Unknown Indication
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 2,065 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 638 |
| DYSPNOEA | 308 |
| SEPSIS | 295 |
| CARDIO-RESPIRATORY ARREST | 279 |
| DIARRHOEA | 276 |
| FALL | 273 |
| HAEMORRHAGIC STROKE | 265 |
| DIZZINESS | 255 |
| ALTERED STATE OF CONSCIOUSNESS | 248 |
| FATIGUE | 232 |
| HEADACHE | 231 |
| DECREASED APPETITE | 225 |
| MALAISE | 224 |
| ASTHENIA | 216 |
| TACHYCARDIA | 212 |
| CHILLS | 211 |
| ASCITES | 209 |
| INSOMNIA | 209 |
| ABDOMINAL PAIN | 208 |
| PYREXIA | 208 |
Reactions in Hospitalization Reports
Top reactions in 6,635 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| DYSPNOEA | 623 |
| PNEUMONIA | 435 |
| FALL | 380 |
| DIZZINESS | 351 |
| FATIGUE | 345 |
| DIARRHOEA | 343 |
| OFF LABEL USE | 336 |
| HYPOTENSION | 320 |
| ASTHENIA | 296 |
| ASTHMA | 272 |
| ACUTE KIDNEY INJURY | 256 |
| HYPERTENSION | 254 |
| PYREXIA | 251 |
| WHEEZING | 244 |
| ATRIAL FIBRILLATION | 241 |
| PRODUCTIVE COUGH | 238 |
| URINARY TRACT INFECTION | 232 |
| ANAEMIA | 229 |
| BENIGN PROSTATIC HYPERPLASIA | 227 |
| NAUSEA | 223 |
Nearby — Related Medications
What the FAERS Data Reveals About tamsulosin Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 18,628 voluntary reports linked to tamsulosin and its brand equivalents (Flomax), spanning 2004 through 2025. Of those, 2,065 (11.1%) listed death as an outcome and 6,635 (35.6%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.
Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 5% were female and 95% male; age distribution skews toward 75+, with 5,689 reports in that bracket. The single most reported reaction is fatigue with 1,417 submissions, followed by dyspnoea and dizziness.
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.