Posted on 08/05/2025 11:30:25 AM PDT by Red Badger
In A Nutshell
A study of nearly 2,700 older adults found no higher risk of brain bleeding in patients taking the blood thinner warfarin.
Even those with very high blood-thinning levels didn’t experience bleeding events after head trauma.
Current ER practices for these patients may be overly cautious, but more research is needed before guidelines change.
Findings could ease concerns for seniors and their families after a fall.
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BOCA RATON, Fla. — For years, doctors have taken extra precautions when older adults on blood thinners arrive in the emergency room with head injuries. These patients often stay in the hospital longer and get multiple brain scans, based on the belief that blood thinners make brain bleeds more likely. But new research suggests that assumption may not always hold true.
A study of nearly 2,700 older adults found that those taking the blood thinner warfarin were not at greater risk of bleeding in the brain after a fall, even if their blood was thinned more than recommended. In fact, the small group of patients with the thinnest blood didn’t experience any bleeding at all.
The study, published in the American Journal of Emergency Medicine, found no clear link between how thin a person’s blood was and their risk of brain bleeding after a head injury. “In older emergency department patients prescribed preinjury warfarin, elevated INR levels do not appear to be a risk factor for acute ICH,” the researchers wrote.
Why Blood Thinners Raise Concerns
Warfarin, sold under the brand name Coumadin, is a common medication used to prevent strokes and blood clots. It works by slowing the blood’s ability to clot. For that reason, doctors have long worried that a head injury while on warfarin could lead to serious internal bleeding.
To track how “thin” a patient’s blood is, doctors use a test called the INR. A normal INR is around 1.0. Patients on warfarin typically aim for a range between 2.0 and 3.0. Higher than that has traditionally been seen as dangerous.
Because falls are so common in older adults, and also because brain bleeds can be deadly, emergency rooms usually take a “better safe than sorry” approach. But that could mean hospital stays and scans that aren’t always needed.
Surprising Results From Florida Hospitals
The new study out of Florida Atlantic University looked at head injury patients aged 65 and older treated at two hospitals in Florida. About 10% of those on warfarin experienced brain bleeding, compared to just under 6% of those not on blood thinners—a small difference that wasn’t considered meaningful.
When researchers looked more closely at warfarin users, they found that those with slightly lower-than-recommended blood-thinning levels had the highest bleeding rate. Meanwhile, those with the highest blood-thinning levels had no bleeds at all.
That finding goes against the grain. Older studies suggested that the thinner your blood, the greater your risk of bleeding. But those studies were smaller and mostly looked backward at past patient records. This one followed patients in real time.
Could Hospital Guidelines Change?
Currently, patients on warfarin who hit their heads are usually admitted for monitoring, just in case bleeding starts later. The new research doesn’t recommend throwing out that practice, but it does suggest a closer look may be warranted.
Warfarin users in the study were more likely to be admitted to the hospital and stayed longer — on average, four days instead of three. That adds stress for patients and families, and costs for the healthcare system.
If other studies confirm these results, doctors might one day feel more confident sending some patients home sooner.
But the researchers caution against jumping to conclusions. The number of patients with the highest blood thinning levels was small, and about 16% of patients didn’t have their levels measured at all. Also, most of the patients were white, so it’s not clear if the results apply broadly to more diverse populations.
Still, the takeaway is hopeful: being on warfarin after a fall may not automatically mean high risk. The real story may be more complicated and potentially less alarming than many people assume.
Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about medications or head injuries.
Paper Summary
Methodology
Researchers conducted a secondary analysis of a prospective study at two Florida trauma centers, tracking 2,686 patients aged 65 and older who came to the emergency department after blunt head trauma. Patients were split into two groups: 263 were taking warfarin pre-injury, and 2,423 were not on anticoagulants or antiplatelet medications. Warfarin patients were further subdivided based on their INR levels. Data on CT scan results and clinical outcomes were collected and patients were followed for 14 days.
Results
The overall rate of intracranial hemorrhage (ICH) was 10.9%. Among warfarin patients, 7.4% developed ICH, compared to 5.7% of patients not on blood thinners. No statistically significant difference was observed between patients with INR levels above 3.0 and those with lower values. Secondary analysis showed the highest ICH rate (19.1%) occurred in patients with INR <2.0. Patients with INR 2.0–3.0 had a 6.8% rate, those with INR 3.1–4.9 had 7.7%, and none of the 11 patients with INR ≥5 experienced any ICH.
Limitations
Only 43 warfarin patients had INR levels above 3.0. Additionally, 16% of warfarin patients did not have INR values recorded. Follow-up was conducted by phone and chart review, which could have missed delayed or minor bleeding events. The cohort was 90% white, limiting generalizability. The study was observational and not randomized, so findings are associative rather than causal.
Funding and Disclosures
The study was funded by the Florida Medical Malpractice Joint Underwriting Association (Grant #2018-01, “The GREAT STOP Project”). The authors declared no conflicts of interest.
Publication Details
Title: Supratherapeutic warfarin and risk of intracranial hemorrhage in geriatric patients with blunt head trauma Authors: Chelsea Caplan, Gabriella Engstrom, Mike Wells, et al.
Journal: American Journal of Emergency Medicine, Volume 96, 2025, pages 75–79
DOI: 10.1016/j.ajem.2025.06.020
Still not taking up bungee jumping, though.
My mother used top take warfarin and her Dr would say there’s warfarin and then there’s rat poison ,LOl
Warfarin is rat poison!..............
Sometimes I hear the crowd in my head yell, “you have been renewed!”
Logan?..................
Curious warfarin (rat poison) is a topic now?
The profit in warfarin has run out.
Xarelto, Eloquis and even newer drugs are far more expensive for Medicare & Medicaid & thus have more room for excess profit.
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