- People may take aspirin for a variety of reasons, such as to help prevent heart attacks. Some people take warfarin to prevent blood clots.
- However, some people who take warfarin also take aspirin. Because aspirin is available over the counter, some people may take it without a recommendation from their doctor.
- The results of a new study show that in some patients taking warfarin, stopping aspirin may help prevent adverse bleeding events.
A recent study published in JAMA looked at how stopping aspirin may benefit some people who are already taking warfarin.
The results suggest that some people may have a lower risk of bleeding if they stop taking aspirin while taking warfarin.
The data is an important reminder for people to discuss their medication use with their doctors.
Use for aspirin and warfarin
Warfarin (also known as Jantoven or Coumadin) is an anticoagulant medication commonly known as a blood thinner. It helps prevent blood clots and reduces the risk of a heart attack or stroke in people who are at high risk of developing blood clots. The following people can take warfarin:
- People with mechanical heart valves
- People who have had a heart attack
- People with atrial fibrillation (a-FIB), an abnormal heart rhythm
Aspirin is a nonsteroidal anti-inflammatory drug. It has multiple uses, including relieving pain and reducing inflammation. Some people take aspirin to reduce the risk of a heart attack or stroke.
In some cases, people may take both warfarin and aspirin. However, this is not always medically indicated. Because both drugs carry the risk of severe bleeding, it is important that people discuss their medications with their doctors, including over-the-counter medications such as aspirin.
Study author Dr. Geoffrey Barnes and cardiology specialist from the University of Michigan Health Frankel Cardiovascular Center explained to MNT:
“Aspirin is not a benign medication, even if it is available over the counter. Be sure to discuss with your doctor the potential benefits and disadvantages of aspirin and decide whether or not you should take aspirin. This is especially true if you are taking another blood thinning medication.”
Taking warfarin and stopping aspirin
The study looked at the effects of reducing aspirin use among people taking warfarin. In particular, this included warfarin participants who had no clear indicator of taking aspirin.
For example, researchers tried to check aspirin use by people who had no history of coronary heart disease or heart attack.
The observational study involved over 6,000 adult participants who took warfarin for either a-Fib or blood clots. In collaboration with primary care professionals, participants were examined to determine whether or not they needed to take aspirin and warfarin.
Aspirin was discontinued when it was not considered medically necessary.
The researchers found that stopping taking aspirin was associated with a reduced risk of bleeding among participants.
This included the risk of severe bleeding episodes and emergency rooms associated with bleeding. They further found that stopping taking aspirin was not associated with increased blood clot events.
Dr. Barnes pointed out the following highlights of the study:
“First, we were able to show that stopping aspirin can reduce the risk of bleeding in patients taking an anticoagulant such as warfarin and also taking aspirin without a clear indication. Second, we were able to show that a systematic approach to evaluating aspirin needs and helping patients stop aspirin when it is not indicated can be highly effective. This is an excellent example of anticoagulation management.”
Study restrictions and areas for further research
The researchers acknowledged that their study had several limitations.
First, they identify limits based on data collection methods and study participants. They find that the study was unable to determine the cause, some data may be overlooked, and the results cannot be generalized.
The use of aspirin was also reported by participants, which increased the risk of data collection errors.
The study only involved participants from one state, and researchers were unable to gather information about incidents of myocardial infarction as accurately as they would have liked. The participants could have received medical care for events that the study could not record. The number of events that occurred was low, which limits some of the data analysis. The study also lacked a control group.
Overall, the study serves as an important reminder to use medications carefully and that some medications, such as aspirin, are not always needed. Because the indications are different for everyone, some people still need the use of aspirin plus warfarin or aspirin plus a newer type of blood thinner, such as Eliquis or Xarelto.
People should work carefully with their doctors to take medication appropriately.
The author outside of the study, Dr. Naveed Saqib, vascular surgeon at UTHealth Houston Heart & Vascular and Memorial Hermann, explained to MNT:
“This study has significant results that will help doctors bleed and remove aspirin from high-risk patients taking combination therapy for. This must also be investigated in patients receiving new oral anticoagulants. Currently, patients with recent heart attacks, heart valves, coronary and carotid stents, and peripheral stents who require anticoagulation continue to require combination therapy with aspirin/clopidogrel plus warfarin/eliquis/Xarelto.”
Dr. Barnes further pointed out the following components of future research:
“While we were able to demonstrate a reduction in bleeding in patients who received warfarin when we stopped taking aspirin, we need to understand how the same approach is used for patients taking direct oral anticoagulants, including apixaban and rivaroxaban. Patients taking these medications are usually not observed in an anticoagulation clinic. That’s why we need to develop new ways to systematically check their medicines and prescribe unnecessary medicines.”