Reported Reactions

Drugs

Product name as reported

Coumadin: adverse event reports filed with FDA

22,987 reports list it as a suspect or interacting product, 2004–2026. Also reported as Coumadin /00014802/, Coumadin /00627701/.

22,987
reports as suspect product
0.1% of all reports · about 1,022 a year
67
reports, 12 months to June 2026
77 in the 12 months before
69.2%
marked serious by the reporter
57.4% across all reports
8.9%
record death among outcomes, as reported
2,042 reports · not verified by FDA

Between January 2004 and June 2026, 22,987 adverse event reports received by FDA list the product name "Coumadin" as reporters wrote it as a suspect or interacting product. Reports that mention it only as a concomitant medication (60,546) are left out of every figure here.

In the 12 months to June 2026, 67 reports listed it, down 13% from 77 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 1,022 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.

Reporters most often recorded international normalised ratio increased (15.9%), drug interaction (6.7%) and gastrointestinal haemorrhage (5.9%). A report can list several reactions, so shares add to more than 100%; 1,736 different terms appear across these reports. International normalised ratio increased is recorded in 15.9% of these reports, against 0.1% of all reports in the database.

69.2% of the reports are marked serious by the reporter; 8.9% record death among the outcomes and 44% record hospitalisation, as reported. 58.1% of the reports came from consumers, and the largest patient age group is 75 and over (30.5%). 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

01631Jul 2021: 13Aug 2021: 19Sep 2021: 31Oct 2021: 11Nov 2021: 9Dec 2021: 82022Jan 2022: 13Feb 2022: 9Mar 2022: 14Apr 2022: 14May 2022: 12Jun 2022: 24Jul 2022: 11Aug 2022: 17Sep 2022: 12Oct 2022: 14Nov 2022: 8Dec 2022: 132023Jan 2023: 7Feb 2023: 7Mar 2023: 12Apr 2023: 13May 2023: 7Jun 2023: 12Jul 2023: 7Aug 2023: 17Sep 2023: 8Oct 2023: 9Nov 2023: 15Dec 2023: 42024Jan 2024: 11Feb 2024: 7Mar 2024: 7Apr 2024: 9May 2024: 11Jun 2024: 3Jul 2024: 6Aug 2024: 12Sep 2024: 2Oct 2024: 8Nov 2024: 7Dec 2024: 112025Jan 2025: 8Feb 2025: 13Mar 2025: 2Apr 2025: 3May 2025: 2Jun 2025: 3Jul 2025: 3Aug 2025: 3Sep 2025: 4Oct 2025: 1Nov 2025: 9Dec 2025: 122026Jan 2026: 6Feb 2026: 8Mar 2026: 3Apr 2026: 1May 2026: 7Jun 2026: 10

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

01,0622,1242004: 66120042005: 1,1302006: 1,2052007: 44620072008: 1,1082009: 1,3282010: 83520102011: 1,8042012: 1,5622013: 1,20820132014: 1,9202015: 2,1242016: 1,94820162017: 1,4422018: 1,2862019: 1,12420192020: 1,0392021: 3432022: 16120222023: 1182024: 942025: 6320252026: 35

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Coumadin reports recording the termall reports in the database

  1. International normalised ratio increasedblood clotting slower than intended (raised INR)15.9%3,658
  2. Drug interactionan interaction between medicines6.7%1,532
  3. Gastrointestinal haemorrhagebleeding in the stomach or bowel5.9%1,350
  4. Haemorrhagebleeding5.8%1,336
  5. Anaemialow red blood cells5.5%1,275
  6. Epistaxisnosebleed4.6%1,062
  7. Falla fall4%919
  8. International normalised ratio fluctuation3.9%901
  9. International normalised ratio decreasedblood clotting faster than intended (low INR)3.7%860
  10. Contusiona bruise3.7%858
  11. International normalised ratio abnormal3.3%760
  12. Drug ineffectivethe medicine did not work as expected3.2%731
  13. Dyspnoeashortness of breath3%688
  14. Thrombosis2.9%658
  15. Astheniaweakness or lack of energy2.8%643
  16. Haematomaa collection of blood under the skin or in tissue2.7%622
  17. Fatiguetiredness2.5%577
  18. Nauseafeeling sick2.4%552
  19. Diarrhoealoose or frequent stools2.3%538
  20. Dizzinesslight-headedness or unsteadiness2.3%522
  21. Haematuriablood in the urine2.2%517
  22. Headachehead pain2.2%511
  23. Deaththe patient died; cause not stated by this term2.1%475
  24. Pulmonary embolisma blood clot in the lung2%463
  25. Vomitingbeing sick1.8%421
  26. Off label useused for a purpose or in a way not on the label1.8%418

Top 30 of 1,736 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

Death8.9%2,042
Life-threatening4.3%984
Hospitalisation (initial or prolonged)44%10,104
Disability1.4%316
Congenital anomaly0.2%44
Other serious36.9%8,490
Not serious30.8%7,076

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 20.1%18
2 to 110.1%25
12 to 170.2%42
18 to 444%920
45 to 6413.6%3,128
65 to 7415.5%3,567
75 and over30.5%7,014
Age not given36%8,273

Patient sex

Female49.9%11,482
Male42.2%9,704
Not given7.8%1,801

Who reported

Physician16.8%3,852
Pharmacist8.9%2,048
Other health professional13.9%3,186
Lawyer0.4%94
Consumer or non-health professional58.1%13,366
Not given1.9%441

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 74.3% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Atrial fibrillation4,25718.5%
Deep vein thrombosis9544.2%
Thrombosis7883.4%
Pulmonary embolism6732.9%
Anticoagulant therapy5582.4%
Thrombosis prophylaxis4111.8%

The indication field is filled in by the reporter and is often blank; shares are of all 22,987 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Coumadin reports
Lasix1,9288.4%
Aspirin1,8568.1%
Xarelto1,6167%
Furosemide1,1004.8%
Plavix1,0584.6%
Lovenox9254%
Lisinopril8283.6%
Lipitor7013%
Digoxin6712.9%
Simvastatin6502.8%

Other products listed in reports where Coumadin 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

MeasureCoumadinAll reports
Reports as suspect product22,98720,646,523
Share of that pool—0.1%
Reports, latest 12 months671,332,454
Marked serious69.2%57.4%
Death recorded among outcomes, per 1,000 reports8991
Hospitalisation recorded, per 1,000 reports440213
Consumer-filed share58.1%45.8%
Top term, share of reportsInternational normalised ratio increased 15.9%0.1%

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 Coumadin reports

How many adverse event reports has FDA received for Coumadin?

22,987 reports list Coumadin as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 67 of them arrived in the latest 12 months. Another 60,546 list it only as a concomitant medication.

What reactions are recorded in Coumadin reports?

international normalised ratio increased (15.9%), drug interaction (6.7%), gastrointestinal haemorrhage (5.9%), haemorrhage (5.8%) and anaemia (5.5%). 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 Coumadin was responsible.

How serious are the reports?

69.2% are marked serious by the reporter. Among the outcomes recorded, 8.9% of reports include death and 44% 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?

consumer or non-health professional (58.1%), physician (16.8%) and other health professional (13.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Coumadin rising?

67 reports in the 12 months to June 2026, down 13% from 77 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 Coumadin 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 Coumadin?

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 Coumadin as a suspect or interacting product; reports listing it only as a concomitant medication (60,546) 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.