Coumadinwarfarin
According to the FDA label: Warfarin sodium tablets are indicated for: Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (PE). Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation (AF) and/or cardiac valve replacement. Reduction in the risk of death, recurrent myocardial infarction (MI), and thromboembolic events such as stroke or systemic embolization after myocardial infarction.
125,609 adverse event reports submitted to the FDA (1999–2026)
Top Reported Adverse Events
The most frequently reported events in association with Coumadin in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
Show these terms with plain-language definitions
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- International Normalised Ratio Increased 10,310 reports
Dyspnoea 8,448 reports
Shortness of breath or difficulty breathing. Also spelled dyspnea in American English.
Full definition in the glossary → See all drugs reporting this event →Drug Interaction 6,331 reports
A report that two or more medications may have affected each other when taken together.
Full definition in the glossary →Fatigue 6,187 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Nausea 5,948 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →Diarrhoea 5,940 reports
Loose or watery bowel movements, often frequent. Also spelled diarrhea in American English.
Full definition in the glossary → See all drugs reporting this event →Dizziness 5,190 reports
A feeling of being lightheaded, unsteady, or like the room is spinning.
Full definition in the glossary → See all drugs reporting this event →Drug Ineffective 5,154 reports
A report that the medication did not work as expected for the person taking it. This is a reporting category, not a sign the drug is defective. It simply means someone felt it was not helping their condition.
Full definition in the glossary →Fall 4,834 reports
A report that the person fell down. Falls are tracked because they can signal issues like dizziness, weakness, or balance problems.
Full definition in the glossary →Death 4,741 reports
A report that the person died. A death appearing in reports for a drug does not mean the drug caused it. Reports record that a death occurred while the medication was being used, which can happen for many unrelated reasons.
Full definition in the glossary →Headache 4,683 reports
Pain in the head or upper neck.
Full definition in the glossary → See all drugs reporting this event →Asthenia 4,388 reports
Physical weakness or lack of strength.
Full definition in the glossary →Pneumonia 4,120 reports
An infection that inflames the air sacs in the lungs, which can cause cough, fever, and difficulty breathing.
Full definition in the glossary →Haemorrhage 4,055 reports
Bleeding, particularly heavy or uncontrolled bleeding. Also spelled hemorrhage in American English.
Full definition in the glossary →Anaemia 3,954 reports
A condition where there are too few healthy red blood cells to carry enough oxygen, often causing tiredness and paleness. Also spelled anemia in American English.
Full definition in the glossary → See all drugs reporting this event →
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Male | 57,882 |
| Female | 56,584 |
| Unknown | 340 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 1,427 |
| 18-34 | 3,057 |
| 35-49 | 7,726 |
| 50-64 | 20,425 |
| 65-74 | 24,086 |
| 75+ | 32,171 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Coumadin. A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Hospitalization | 57,546 |
| Other Serious | 55,219 |
| Non-Serious | 25,393 |
| Death | 16,035 |
| Life-Threatening | 8,147 |
| Disability | 3,621 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Coumadin. Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 1999 | 1 |
| 2004 | 2,226 |
| 2005 | 2,631 |
| 2006 | 2,679 |
| 2007 | 2,657 |
| 2008 | 3,130 |
| 2009 | 3,568 |
| 2010 | 4,552 |
| 2011 | 4,864 |
| 2012 | 5,364 |
| 2013 | 5,250 |
| 2014 | 7,742 |
| 2015 | 10,029 |
| 2016 | 10,358 |
| 2017 | 9,931 |
| 2018 | 10,902 |
| 2019 | 9,482 |
| 2020 | 7,886 |
| 2021 | 6,216 |
| 2022 | 4,693 |
| 2023 | 4,063 |
| 2024 | 3,628 |
| 2025 | 3,090 |
| 2026 (partial) | 667 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Coumadin
In FDA adverse event reports that mention Coumadin, these medications appeared most often in the same report.
- Furosemide (24,944 reports)
- Aspirin (13,226 reports)
- Metoprolol (12,023 reports)
- Omeprazole (11,709 reports)
- Digoxin (10,377 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026