CLOT+

Doctor, I have finished 6 months of Xarelto® for my blood clot. Can I switch to aspirin now?

Continuing Xarelto® will protect you from developing another blood clot better than taking aspirin. After 6 months, some people can switch to a lower dose of Xarelto®, which appears to work just as well as the standard dose.

Study highlights

People who took low-dose Xarelto® did not have more new blood clots than people who continued standard dose Xarelto®.

Both doses of Xarelto® prevented more blood clots than aspirin.

People who took either dose of Xarelto® did not have more major bleeding than people who took aspirin. 

Understanding the problem

Anticoagulants protect people who have deep vein thrombosis or pulmonary embolism from forming new blood clots while their body works on breaking down the old blood clots. How long people with DVT or PE should take an anticoagulant is not based on when the clot is gone. Instead, it is based on when the risk factor that caused the blood clot is gone.

For example, Alice develops a DVT one week after hip replacement surgery. She is treated with anticoagulants for 3 months, and then her doctor tells her she can stop taking them. Alice's risk factor for DVT was surgery. Her DVT is called "provoked". 

For many people, the risk factor that caused the DVT or PE is either weak (e.g. travel) or unknown. This type of DVT or PE is called "unprovoked". These people remain at risk for forming new blood clots for the rest of their lives. To protect themselves from another clot, they may decide to take anticoagulants indefinitely.

Anticoagulants also have safety concerns because they increase the risk of bleeding.

For example, Sam has an ulcer in his stomach that is bleeding, but so slowly, he hasn't noticed it. But when Sam is diagnosed with a PE and starts taking anticoagulants, the bleeding from his ulcer increases and he vomits up blood.

Researchers are always looking for ways to protect people from blood clots while lowering the risk of bleeding. For this reason, the study described below was designed to find out if aspirin was just as good at preventing new blood clots as Xarelto®, but with a lower risk of bleeding.

Who? The study included 3396 adults (average age 59; 57% male) who completed 6 to 12 months of standard dose Xarelto® for DVT or PE, and the risk factor that caused their DVT or PE was either weak or unknown. 

What? The study compared 2 doses of Xarelto® (20 mg daily or 10 mg daily) with aspirin (100 mg daily).

Xarelto®

vs

Aspirin

Xarelto® 20 mg once a day (standard dose)

Xarelto® 10 mg once a day (low dose)


Aspirin 100 mg once a day


Xarelto® vs aspirin in patients with DVT or PE who had completed 6 to 12 months of Xarelto®

Outcomes at 1 year

Rate of events with Xarelto®, 20 mg daily

Rate of events with Xarelto®, 10 mg daily

Rate of events with aspirin, 100 mg daily

Results

DVT

1 out of 100 people

1 out of 100 people

3 out of 100 people

About 2 fewer people out of 100 who took Xarelto® had a new DVT at 1 year.

PE

1 out of 100 people

1 out of 100 people

2 out of 100 people

About 1 less person out of 100 who took Xarelto® had a new PE at 1 year.

Serious bleeding1 out of 100 people1 out of 100 people1 out of 100 peopleNo difference

*Although the rates for the 2 groups look different, the differences were not statistically significant—this means that the difference could simply be due to chance rather than due to the different treatments.

This Evidence Summary is based on the following article:

Weitz JI, Lensing AWA, Prins MH, et al. Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism. N Engl J Med. 2017 Mar 30;376(13):1211-1222.  PubMed

Published: Friday, May 11, 2018
Last Updated: Thursday, July 30, 2020


This Evidence Summary is also available in other formats:

Read the GP Summary