Balancing XARELTO® Risks and Benefits

All blood thinners come with a risk of bleeding. So how can you know that a blood thinner will be right for you? Before prescribing a blood thinner, your healthcare professional may evaluate treatment options for you based not only on your risk for blood clots, but also on your risk for bleeding. If you and your healthcare professional choose XARELTO®, it is because the benefit of helping to protect you against blood clots and their potentially devastating effects outweighs your risk of bleeding.

It may also be helpful to learn more about what information your healthcare professional may take into account to make this decision.

Understanding the types of bleeding

It’s important to understand that when healthcare professionals talk about bleeding risks with blood thinners, they are considering two different types of bleeding:

  • Minor bleeds, like bruising or bleeding of the gums
  • Major bleeds, like those that occur in the brain, and can be life threatening

Major bleeds can have devastating, life-altering effects, and all bleeding events should be taken seriously. Now that you know there is more than one type of bleeding, it may help to ask your healthcare professional about the rates of both minor and major bleeding seen in clinical studies.

Evaluating clinical studies

Health of patient populations

Clinical studies publish certain health information about the patients taking part in the study. This matters because the health of people taking part in the study can affect how well the drug works and also the type and severity of side effects. Medicines should be safe and effective for the people for whom they are intended. The health of patients enrolled in clinical studies also matters when your healthcare professional looks at the rates of side effects, like bleeding.

In general, a person’s risk for bleeding tends to increase with age, even before taking a blood thinner. The CHA2DS2-VASc score* is used to help determine the risk of stroke in people with atrial fibrillation (AFib). The higher your CHA2DS2-VASc score, the higher your risk for an AFib-related stroke. People with a higher CHA2DS2-VASc score also have more risk factors, such as diabetes and hypertension.

If a clinical study only looks at healthier people, that study’s results may also show a lower rate of some side effects, such as bleeding. However, XARELTO® has been studied in more than 230,000 people since 2011—including older people with more health issues—and was also studied in real-world settings. When exploring treatment options with your healthcare professional, you should discuss your health and how that affects your personal risk level.

*The CHA2DS2-VASc score is a sum of total points (0–9) assigned to the following risk factors: congestive heart failure, hypertension, 75 years of age or older, diabetes, prior stroke, vascular disease, 65–74 years of age, being female.

Impact of once-daily vs twice-daily dosing in clinical studies

How often a medicine needs to be taken may have an effect on the results of clinical studies. For instance, if a medicine needs to be taken twice a day but some of the enrolled patients forget to take the medicine twice a day on a regular basis, you might see a lower rate of side effects, like bleeding, which may suggest the medicine is safer. What we can say is that failing to take medicines as prescribed can affect their ability to do what they are supposed to do. In the case of blood thinners, the medicine may not be as effective in helping to prevent potentially devastating events, like strokes in people with AFib.

Clinical studies vs "Real-World Evidence" studies

Healthcare professionals rely on the results of clinical studies to prescribe the right medicines to their patients. But sometimes, a medicine that was proven safe and effective in a clinical study does not show the same results once it is being widely prescribed for a broader population. This is because the overall health of the people in the clinical study may not be reflective of those treated with the medication in a real-world setting. The US Food and Drug Administration (FDA) defines "Real-World Evidence" as clinical evidence derived from the analysis of data gathered from various sources such as electronic health records (EHRs), claims and billing activities, product and disease registries, and patient-generated data.

So when healthcare professionals see that the results of "Real-World Evidence" studies are consistent with the results of the original clinical studies, they may be more confident prescribing that medicine to their patients. When discussing medication options, it may be important to consider the risk profile of the patient populations studied and how that compares to someone like you.

As for XARELTO®, the “Real-World Evidence” has been generally consistent with the results of the original clinical studies.

Note that you should not directly compare the results of “Real-World Evidence” studies and clinical trials because the approaches are different.

XARELTO® bleeding rates


In a clinical study comparing XARELTO® to warfarin for reducing the risk of AFib-related stroke:


In clinical studies of people taking XARELTO® to treat a DVT or PE:

Recurrent DVT/PE

In clinical studies of people taking XARELTO® to help reduce their risk of recurrent DVT or PE after at least six months of initial treatment:

Knee and Hip Replacement Surgery

In clinical studies of people taking XARELTO® to reduce their risk of DVT or PE blood clots following knee or hip replacement surgery:


In a clinical study of people taking XARELTO® 2.5 mg twice daily with low-dose aspirin once daily to reduce the risk of major cardiovascular events:

PAD Post Vascular Intervention

In a clinical study of people taking XARELTO® 2.5 mg twice daily with low-dose aspirin once daily to reduce the risk of major cardiovascular and leg events:

99% of people taking XARELTO® did not experience a serious bleed, such as bleeding into the brain. However, overall major bleeding was similar and gastrointestinal bleeding was about 1% higher.


Patients experienced a serious bleed - 0.2% for XARELTO® and 0.5% for warfarin. Patients experienced a gastro-intestinal bleed - 2.0% for XARELTO® and 1.2% for warfarin.

1% of patients taking XARELTO® experienced major bleeding vs 1.7% of patients taking the standard treatment enoxaparin and warfarin (Coumadin®).

Less than 1% of patients taking XARELTO® experienced major bleeding, which is similar to the rate of major bleeding in patients taking aspirin to reduce their risk of recurrent DVT or PE.

Less than 1% of patients taking either XARELTO® or enoxaparin, the standard treatment option, experienced a major bleeding event—0.3% with XARELTO® and 0.2% with enoxaparin.

Around 3% of people experienced a major bleeding event, such as bleeding into the brain. That represents about a 1% increase in bleeding in patients taking XARELTO® in addition to low-dose aspirin versus people taking only low-dose aspirin.

Less than 2% of people taking XARELTO®, in combination with aspirin, experienced a major bleeding event versus around 1% of people taking only low-dose aspirin.