Blood Thinners: Anticoagulants & Antiplatelet Drugs

Doctors prescribe blood thinners to prevent clots that can cause heart attacks and strokes. This is important for patients with certain heart conditions, such as atrial fibrillation (AFib), and those who have undergone procedures, such as heart valve replacement.


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Patients who have received heart valve replacements and undergo other procedures take certain drugs to reduce blood clots. These so-called blood thinners (anticoagulants and antiplatelets) don’t actually make blood thin. Rather, they are drugs that decrease blood clots and keep existing clots from growing.

Did You Know?
Commonly prescribed blood thinners include Pradaxa, Xarelto and Eliquis.
Source: American Heart Association

Clots can block the blood flow to the heart, lungs and brain, causing heart attacks and strokes. Blood thinners are also given to patients after some surgical operations, such as knee and hip replacement.

People with an irregular heartbeat called atrial fibrillation (AFib) are five times more likely to have a stroke. And when they have strokes, they are twice as likely to be left unable to care for themselves or talk. They are also twice as likely to be unable to move at least one side of the body.

Pradaxa, Xarelto and Eliquis are among the blood thinners approved by the U.S. Food and Drug Administration in recent years.

While blood thinners lower clotting risks, they also come with potential pitfalls. These are mainly related to bleeding and can be minor, such as bruising, or major, such as bleeding in the brain.

blood thinner illustration


Warfarin Tablet
The oldest anticoagulant is warfarin, also known as Coumadin or Jantoven.

Anticoagulants slow down the process of making clots. They do this by targeting clotting factors, proteins made in the liver. These proteins need Vitamin K to form.

Warfarin patients need routine blood testing to monitor how quickly their blood clots.

In 2018, Warfarin patients who want to make monitoring easier will be able to purchase a new handheld device – Roche’s CoaguChek Vantus, the first self-testing device for coagulation monitoring with Bluetooth technology.

Anticoagulants compete with Vitamin K, inhibiting the circulation of clotting factors. They are recommended for people with atrial fibrillation and who are at high risk of strokes caused by clots originating in the heart. They are also prescribed for people with heart valve replacements, phlebitis and congestive heart failure.

Types of Anticoagulant Drugs
Hep-Lock (heparin)
This drug, also known as Hep-Lock, HepFlush-10, comes as a liquid that is injected. It works fast and is given when that is needed. It prevents the proteins thrombin and fibrin from working the way they’re supposed to in helping the blood to clot.
Lovenox (enoxaparin)
Lovenox, like heparin, is injectable. It is made from heparin, but it produces a more predictable anticoagulant response. Patients don’t need to be monitored as closely as those taking heparin. Patients can inject themselves with enoxaparin at home.
Pradaxa (dabigitran)
Pradaxa is part of a newer class of blood thinners. It was approved in 2010. It inhibits the clotting factor called thrombin.
Eliquis (apixaban)
Eliquis was approved in 2012. It inhibits the clotting factor known as Xa. This enzyme comes before thrombin in the biological steps of clotting blood.
Xarelto (Rivaroxaban)
Xarelto, approved in 2011, is a Factor Xa inhibitor.
Coumadin (warfarin)
Coumadin weakens Vitamin K, prolonging clotting time.
Blood thinner icons

Antiplatelet Drugs

Antiplatelet drugs like aspirin reduce the severity of strokes and heart attacks and prevent them from occurring.

The most common and widely used blood thinner is aspirin, an antiplatelet drug.

Antiplatelet drugs prevent blood cell fragments known as platelets from sticking together and forming clots. They do this by inhibiting the production of a chemical that signals platelets to stick together.

This chemical process is needed when you are cut and the platelets form a scab to seal the wound. But it can threaten the lives of stroke survivors by creating clots that can block blood from flowing to the brain or heart.

Types of Antiplatelet Drugs
Plavix (clopidogrel)
Plavix works by reducing the number of platelets in the blood, limiting its ability to clot.
Effient (prasugrel)
Effient works by irreversibly blocking the platelet receptor P2Y12 ADP, inhibiting platelet function.
Brilinta (ticagrelor)
Brilinta reversibly interacts with the platelet P2Y12 ADP-receptor to prevent platelets from sticking together.
Persantine (dipyridamole)
Persantine stimulates the production of prostacyclin, which inhibits platelet activation.
Ticlid (ticlopidine)
Ticlid interacts with the platelet P2Y12 ADP-receptor to prevent platelet activation.
Aspirin, also sold under the Easprin and Ecotrin brand names, inhibits a blood-clotting chemical called thromboxane.
Blood thinner icons

Blood Thinner Precautions

Patients taking blood thinners must follow instructions precisely.

Blood Thinners & Pregnancy
Patients should alert their doctors if they are pregnant or plan to get pregnant.

They also must communicate with their doctors about all other medications and supplements they are taking.

Patients also should tell their doctors if they are taking blood thinners before any surgical or dental procedure.

Women should be aware of pregnancy risks.

Many blood thinners can cause birth defects or bleeding that can harm fetuses.


Ask your doctor about the risks of alcohol and tobacco use while taking these medications and potential interactions with other medicines or supplements.

Some drugs increase the effects of anticoagulants and the chance of bleeding. Others decrease the effects and increase the chance of blood clots.

Such interactions can be dangerous to your health.

Dietary Concerns

Most blood thinners can cause deficiencies of certain nutrients, including vitamin D, vitamin C and calcium. Some doctors may recommend taking supplements to compensate for this.

Avoiding Falls and Injuries

When you are taking blood thinners, you should be extra careful about avoiding injuries.

  • Make sure things you need are easy to reach
  • Keep a working flashlight or a cell phone close to your bed
  • Minimize clutter, remove throw rugs

Side Effects

Possible side effects of Xarelto and other blood thinners include uncontrolled internal bleeding, bruising and rash.

Get help immediately if:
  • Your urine turns dark red or dark brown
  • Your stools turn red, dark brown or black
  • You bleed more than normal during your period
  • You are coughing up blood
  • Your gums or nose bleeds and doesn’t stop quickly
  • You experience bad headaches or stomach pain that doesn’t go away
  • You are feeling sick, weak, faint or dizzy
  • You have an increase in bruises or blood blisters
  • You have a cut that doesn’t stop bleeding

Please seek the advice of a medical professional before making health care decisions.

22 Cited Research Articles

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  6. Texas Heart Institute. (n.d.). Antiplatelet Therapy. Retrieved from
  7. National Jewish Health. (n.d.). MEDfacts. What You Need to Know When Taking Anticoagulation Medicine. Retrieved from
  8. Paikin, J. and Eikelboom, J.W. (2012, March 12). Aspirin. Retrieved from
  9. Healthline. (n.d.). Blood Thinners for Heart Disease. Retrieved from
  10. Mayo Clinic. (n.d.). Daily aspirin therapy: Understand the benefits and risks. Retrieved from
  11. Agency for Healthcare Research and Quality. (n.d.). Blood Thinner Pills: Your Guide to Using Them Safely. Retrieved from
  12. Sinatra, S. (n.d.) Common Blood Thinners and Anticoagulant Drugs. Retrieved from
  13. The Johns Hopkins Lupus Center. (n.d.). Anticoagulants. Retrieved from
  14. U.S. Food and Drug Administration. (n.d.). Generic Enoxaparin Questions and Answers. Retrieved from
  15. Nordqvist, C. (2017, October 13). Plavix: What does it do and is it safe? Retrieved from
  16. Jauregui, M., et al. (2009, August). Prasugrel (Effient), an Adenosine Diphosphate Receptor Antagonist for the Treatment Of Acute Coronary Syndrome. Retrieved from
  17. Medscape. (n.d.) ticagrelor (Rx). Retrieved from
  18. Medscape. (n.d.) ticlopidine (Rx). Retrieved from
  19. Science Direct. (n.d.). Dipyridamole. Retrieved from
  20. American College of Cardiology. CardioSmart. (n.d.). Understanding Risks of Stroke and Blood Thinners. Retrieved from
  21. Cigna. (n.d.). Blood Thinners Other Than Warfarin: Taking Them Safely. Retrieved from
  22. Roche introduces first self-testing device for Warfarin monitoring with built in Bluetooth® technology. (2018, June 11). Retrieved from
View All Sources
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