heparin Side Effects
Also known as: Heparin Sodium
Analysis of 12,966 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
12,966
Death-Related
2,519
19.4% of reports
Hospitalizations
5,169
39.9% 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 2,519 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 364 |
| SEPSIS | 339 |
| MULTIPLE ORGAN DYSFUNCTION SYNDROME | 309 |
| VOMITING | 279 |
| NAUSEA | 277 |
| GENERAL PHYSICAL HEALTH DETERIORATION | 266 |
| OFF LABEL USE | 264 |
| HEPARIN-INDUCED THROMBOCYTOPENIA | 254 |
| CARDIOGENIC SHOCK | 240 |
| ABDOMINAL PAIN | 239 |
| HYPONATRAEMIA | 233 |
| CONSTIPATION | 227 |
| STRESS | 227 |
| ASCITES | 224 |
| PULMONARY EMBOLISM | 216 |
| ABDOMINAL DISTENSION | 215 |
| APPENDICITIS | 209 |
| APPENDICOLITH | 206 |
| VENTRICULAR FIBRILLATION | 198 |
| CONDITION AGGRAVATED | 197 |
Reactions in Hospitalization Reports
Top reactions in 5,169 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| HEPARIN-INDUCED THROMBOCYTOPENIA | 565 |
| PYREXIA | 329 |
| NAUSEA | 308 |
| ANAEMIA | 294 |
| VOMITING | 287 |
| OFF LABEL USE | 284 |
| DRUG INEFFECTIVE | 283 |
| PULMONARY EMBOLISM | 277 |
| DYSPNOEA | 269 |
| SEPSIS | 256 |
| PNEUMONIA | 253 |
| CONDITION AGGRAVATED | 230 |
| DIARRHOEA | 220 |
| THROMBOSIS | 213 |
| ABDOMINAL PAIN | 212 |
| THROMBOCYTOPENIA | 212 |
| FEBRILE NEUTROPENIA | 204 |
| HYPOTENSION | 201 |
| CONSTIPATION | 190 |
| HAEMOGLOBIN DECREASED | 189 |
Nearby — Related Medications
What the FAERS Data Reveals About heparin Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 12,966 voluntary reports linked to heparin and its brand equivalents (Heparin Sodium), spanning 2004 through 2025. Of those, 2,519 (19.4%) listed death as an outcome and 5,169 (39.9%) 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, 45% were female and 53% male; age distribution skews toward 45-64, with 2,924 reports in that bracket. The single most reported reaction is heparin-induced thrombocytopenia with 1,207 submissions, followed by drug ineffective 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.