What Are the Top 5 Blood Thinners?

Blood thinners are drugs that prevent blood clots from forming in people who are at a high risk of diseases of the heart and blood vessels.

Blood thinners can prevent clotting and stave off the growth of existing clots but can lead to serious, potentially life-threatening bleeding if not taken in the recommended dosage.

Blood clots help stop bleeding from wounds and prevent excessive bleeding when a blood vessel is injured. However, they can block blood vessels and prevent blood flow to organs such as the brain, heart, or lungs, causing a heart attack, stroke, or other serious medical problems.

Blood thinners help prevent blood clots from traveling to the brain and causing a stroke. They ward off the development of blood clots in the veins of the legs (deep vein thrombosis) that can move to the lungs and cause a life-threatening pulmonary embolism.

For most people with atrial fibrillation or a history of blood clots in their legs or lungs, warfarin (coumadin) used to be the only drug prescribed as an oral anticoagulant medication. However, now newer medications called direct oral anticoagulants are available that can be prescribed depending on the individual’s overall health and lifestyle.

Blood thinners are prescribed to treat a variety of health conditions that can cause blood clots, including:

• Certain heart or blood vessel diseases
• Atrial fibrillation (an abnormal heart rhythm)
• Heart valve replacement
• Risk of blood clots after surgery, such as hip or knee replacement surgery
• Congenital heart defects
• Diseases of the blood vessels, such as deep vein thrombosis or pulmonary embolism

The main types of blood thinners are anticoagulants and antiplatelets:

• Anticoagulants
  • Slow down the process of clot formation by targeting clotting factors—proteins thrombin and fibrin and vitamin K. They also help blood flow smoothly through blood vessels and work to reduce a person’s risk of blood clots.
  • Examples include:
    • Heparin 
    • Warfarin
    • Lovenox
• Antiplatelets
  • Prevent platelets from clumping together to form a clot at the site of blood vessel injuries. Many of these medications act on receptors—proteins that receive chemical signals and cause cells to bind—to achieve this effect. They are preferably given to people who have a history of heart attack or stroke.
  • Examples include:
    • Aspirin
    • Clopidogrel
    • Ticagrelor

Natural blood thinners are non-medication products that slow or prevent blood clotting. These may include alcohol and certain foods and herbs, such as garlic, ginger, celery seed, and aniseed.

Water also has the potential to naturally thin the blood. Dehydration causes the blood to thicken, which can lead to an increased risk of clots. 

Warfarin

• Warfarin works by inhibiting vitamin K, which is an essential component in the formation of clots. 
• Consequently, changes in the dietary intake of vitamin K (found in green leafy vegetables, broccoli, cauliflower, and other foods) can affect the activity of warfarin. 
• People who take warfarin have to undergo periodic calculations of their international normalized ratio (INR), a measurement of how long it takes blood to form a clot. A high INR possesses a higher risk of blood clots, whereas a lower INR suggests an increased risk of bleeding. Hence, people on warfarin need frequent dosage adjustments to keep their INR within a therapeutic range.
• Moreover, a wide array of medications and supplements can interact with warfarin and alter its effects.

Direct oral anticoagulants (DOACs)

• Given in fixed doses
• Much more convenient
• Do not require INR monitoring
• Fewer medication interactions
• Do not require dietary restrictions
• Lower risk of bleeding than warfarin
• Easier to stop before surgery or other invasive medical procedures and to resume it later

Bleeding is the primary risk associated with blood thinners. Blood thinners can cause an upset stomach, nausea, and diarrhea.

Although studies have reported that the newest drugs work as well as warfarin, direct oral anticoagulants (DOACs) do have some downsides despite their advantages:

• DOACs are more expensive than warfarin.
• Warfarin remains the preferred choice for people with liver disease, kidney failure, mechanical heart valves, and certain clotting disorders (thrombophilia).
• Warfarin offers protection for several days, whereas DOACs have much shorter half-lives.
• Missed doses of the newer drugs, especially those taken once a day, can leave the individual completely unprotected (making it a bad option for non-compliant people).

Because blood thinners can interact with certain foods, medicines, vitamins, and alcohol, doctors recommend the following before choosing an anticoagulant:

• Inform your doctor about all supplements or medications you are taking that inhibit blood clottings such as aspirin, nonsteroidal anti-inflammatory drugs, clopidogrel, prasugrel, ticagrelor, or any other medication that contains heparin.
• While on anticoagulation therapy, avoid contact sports or other activities that might increase your risk of a potentially life-threatening bleeding event.
• Carry a card in your wallet or wear a bracelet or pendant that helps identify which anticoagulant drug you take.
• Always take blood thinners exactly as prescribed to avoid any unnecessary risks or side effects.
• People who drink alcohol while taking warfarin may be at risk of excessive bleeding because alcohol can enhance the drug’s anticoagulation effects.
• Foods to limit while taking blood thinners may include:
  • Spinach
  • Kale
  • Swiss chard
  • Parsley
  • Cabbage
  • Endive
  • Asparagus
  • Vitamin E supplements
  • Dietary supplements with vitamin K