Reported Reactions

Drugs

Generic name

Heparin: adverse event reports filed with FDA

14,298 reports list it as a suspect or interacting product, 2004–2026. Also reported as Heparin Unspecified, Heparin /00027704/, Heparin Injection.

14,298
reports as suspect product
0.1% of all reports · about 636 a year
545
reports, 12 months to June 2026
746 in the 12 months before
92.6%
marked serious by the reporter
57.4% across all reports
19.8%
record death among outcomes, as reported
2,834 reports · not verified by FDA

14,298 adverse event reports received by FDA list heparin, a generic name as a suspect or interacting product, from January 2004 to June 2026. A further 34,273 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 545 reports listed it, down 27% from 746 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 636 reports a year and 0.1% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

The reactions recorded most often are heparin-induced thrombocytopenia (14.1%), drug ineffective (8.8%) and thrombocytopenia (6%). A report can list several reactions, so shares add to more than 100%; 1,708 different terms appear across these reports. Heparin-induced thrombocytopenia is recorded in 14.1% of these reports, against 0% of all reports in the database.

92.6% of the reports are marked serious by the reporter; 19.8% record death among the outcomes and 46.4% record hospitalisation, as reported. 38.5% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (24.6%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

057113Jul 2021: 104Aug 2021: 96Sep 2021: 102Oct 2021: 58Nov 2021: 69Dec 2021: 932022Jan 2022: 42Feb 2022: 50Mar 2022: 59Apr 2022: 69May 2022: 87Jun 2022: 46Jul 2022: 92Aug 2022: 55Sep 2022: 53Oct 2022: 64Nov 2022: 58Dec 2022: 602023Jan 2023: 67Feb 2023: 59Mar 2023: 78Apr 2023: 58May 2023: 63Jun 2023: 66Jul 2023: 68Aug 2023: 53Sep 2023: 45Oct 2023: 85Nov 2023: 54Dec 2023: 602024Jan 2024: 74Feb 2024: 55Mar 2024: 49Apr 2024: 75May 2024: 79Jun 2024: 59Jul 2024: 107Aug 2024: 58Sep 2024: 64Oct 2024: 113Nov 2024: 27Dec 2024: 442025Jan 2025: 46Feb 2025: 47Mar 2025: 50Apr 2025: 85May 2025: 38Jun 2025: 67Jul 2025: 52Aug 2025: 72Sep 2025: 58Oct 2025: 40Nov 2025: 26Dec 2025: 482026Jan 2026: 62Feb 2026: 34Mar 2026: 52Apr 2026: 39May 2026: 39Jun 2026: 23

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

05221,0442004: 29620042005: 3742006: 3022007: 26620072008: 8992009: 6362010: 34620102011: 4202012: 4322013: 61420132014: 4782015: 6632016: 64320162017: 8062018: 1,0442019: 97920192020: 9722021: 9542022: 73520222023: 7562024: 8042025: 62920252026: 249

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Heparin reports recording the termall reports in the database

  1. Heparin-induced thrombocytopenia14.1%2,020
  2. Drug ineffectivethe medicine did not work as expected8.8%1,264
  3. Thrombocytopenialow platelets6%851
  4. Off label useused for a purpose or in a way not on the label5.1%735
  5. Haemorrhagebleeding4.9%694
  6. Hypotensionlow blood pressure3.8%538
  7. Pulmonary embolisma blood clot in the lung3.6%519
  8. Foetal exposure during pregnancythe unborn baby was exposed to the medicine3.5%504
  9. Maternal exposure during pregnancythe mother took the medicine during pregnancy3.4%480
  10. Gastrointestinal haemorrhagebleeding in the stomach or bowel3.2%460
  11. Deep vein thrombosisa blood clot in a deep vein3.1%443
  12. Haemoglobin decreasedlow haemoglobin3.1%438
  13. Thrombosis2.8%400
  14. Premature babya baby born early2.8%396
  15. Dyspnoeashortness of breath2.8%395
  16. Haematomaa collection of blood under the skin or in tissue2.7%389
  17. Exposure during pregnancythe medicine was taken during pregnancy2.5%356
  18. Anaemialow red blood cells2.5%352
  19. Cardiac arrestthe heart stopped2.4%343
  20. Platelet count decreasedlow platelet count2.3%331
  21. Nauseafeeling sick2.3%323
  22. Condition aggravatedthe condition being treated got worse2.1%306
  23. Drug interactionan interaction between medicines2%293
  24. Deaththe patient died; cause not stated by this term2%292
  25. Activated partial thromboplastin time prolonged1.8%253
  26. Product use in unapproved indicationused for a purpose not on the label1.8%253

Top 30 of 1,708 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Death19.8%2,834
Life-threatening17%2,437
Hospitalisation (initial or prolonged)46.4%6,636
Disability3%436
Congenital anomaly0.7%103
Other serious53.7%7,683
Not serious7.4%1,056

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 21%136
2 to 111.3%189
12 to 170.9%126
18 to 4414.2%2,031
45 to 6424.6%3,513
65 to 7417.3%2,467
75 and over15.1%2,164
Age not given25.7%3,672

Patient sex

Female38.4%5,486
Male45.7%6,541
Not given15.9%2,271

Who reported

Physician28.2%4,026
Pharmacist17.1%2,446
Other health professional38.5%5,508
Lawyer0.7%96
Consumer or non-health professional9.7%1,380
Not given5.9%842

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 53.2% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Anticoagulant therapy2,00914.1%
Thrombosis prophylaxis1,0167.1%
Deep vein thrombosis5323.7%
Pulmonary embolism4993.5%
Prophylaxis2651.9%
Acute myocardial infarction2571.8%

The indication field is filled in by the reporter and is often blank; shares are of all 14,298 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Heparin reports
Aspirin2,50517.5%
Clopidogrel1,2018.4%
Acetylsalicylic Acid8065.6%
Warfarin7815.5%
Furosemide7405.2%
Xarelto4513.2%
Vancomycin4202.9%
Dexamethasone4182.9%
Prednisone4152.9%
Fentanyl3992.8%

Other products listed in reports where Heparin is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureHeparinAll reports
Reports as suspect product14,29820,646,523
Share of that pool—0.1%
Reports, latest 12 months5451,332,454
Marked serious92.6%57.4%
Death recorded among outcomes, per 1,000 reports19891
Hospitalisation recorded, per 1,000 reports464213
Consumer-filed share9.7%45.8%
Top term, share of reportsHeparin-induced thrombocytopenia 14.1%0%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Questions about Heparin reports

How many adverse event reports has FDA received for Heparin?

14,298 reports list Heparin as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 545 of them arrived in the latest 12 months. Another 34,273 list it only as a concomitant medication.

What reactions are recorded in Heparin reports?

heparin-induced thrombocytopenia (14.1%), drug ineffective (8.8%), thrombocytopenia (6%), off label use (5.1%) and haemorrhage (4.9%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Heparin was responsible.

How serious are the reports?

92.6% are marked serious by the reporter. Among the outcomes recorded, 19.8% of reports include death and 46.4% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

other health professional (38.5%), physician (28.2%) and pharmacist (17.1%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Heparin rising?

545 reports in the 12 months to June 2026, down 27% from 746 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Heparin was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Heparin?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Heparin as a suspect or interacting product; reports listing it only as a concomitant medication (34,273) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.