The Most Common Blood Thinners

Blood thinners or anticoagulant medications are used to prevent and treat blood clots. They are commonly prescribed to patients at risk or already diagnosed with deep vein thrombosis (DVT), atrial fibrillation (A-Fib), or any other heart and blood vessel disease. Blood clots are harmful to health and can lead to heart attacks and strokes. A blood thinner reduces the chances of complications due to a blood clot.

The most common blood thinners include traditional options like warfarin (Coumadin), direct oral anticoagulants (DOACs), low-molecular-weight heparin (LMWH), and antiplatelet drugs. DOACs, while being newer and potentially more expensive, have become popular due to their convenience and efficacy.

Continue reading to learn more about what blood thinning medications are used most often, how they work, potential side effects, and proper uses to keep in mind. While using blood thinners, it is essential to attend all follow-up appointments and follow instructions in treatment and ongoing monitoring from your doctor to ensure safety and efficacy of your blood thinner therapy.

What is a blood clot?

Blood clotting is an important natural process in the body to prevent life-threatening blood loss from an injury. Naturally, blood clots are dissolved after the injury is healed. However, when a blood clot spontaneously forms inside blood vessels without a causative injury, this can lead to serious health consequences.

A blood clot, or a thrombus, is a clump formed inside blood vessels when blood, naturally a liquid, turns solid. As mentioned, blood clots form due to the automatic body's defense system to stop excessive bleeding when blood vessels are damaged. The blood clotting process is a complex cascade involving different clotting factors essential to bind blood cells together to form blood clots. However, blood clots can become problematic when they form inside a person’s veins or arteries and compromise the blood flow as a result. There are several risk factors that can put a person at risk for developing blood clots. Certain medical conditions and medication side effects play significant roles here.

Thrombosis is when blood clots block certain blood vessels. The following are the major types of blood clots:

Arterial thrombosis

They impede the blood flow inside arteries. An artery carries oxygen-rich blood from the heart and supplies different body parts. Peripheral artery disease (PAD) can occur when the arteries in the arms or legs are narrowed due to plaque accumulation. PAD can cause pain, numbness, and weakness in the limbs. Besides PAD, arterial thrombosis can be fatal when the blood clots compromise the blood flow to the heart or brain, leading to heart attacks and strokes.

Venous thrombosis

The veins carry deoxygenated blood from the body back to the heart. Venous thrombosis is blood clots in the veins. Venous clots can lead to deep vein thrombosis (DVT) or pulmonary embolism (PE).

Prolonged immobility, atrial fibrillation, clotting disorders, surgery, pregnancy, obesity, smoking, and genetic predispositions can be the causes of blood clots. Existing clots can cause organ damage, tissue death, stroke, heart attack, or even death in serious cases.

How blood thinner pills work to prevent blood clots

As mentioned, blood clotting is a complex process involving different clotting factors. Blood thinners work by interfering with the normal clotting process. While their names can be misleading, remember that blood thinners do not make blood “thinner.” They are designed to make it harder for blood clots to form.

Also, there are different types of blood thinners, and while they all work to reduce the risk of blood clots, these different types of blood thinner have their unique working mechanism.

Warfarin (Coumadin), the oldest blood thinner, works by blocking the activity of vitamin K-dependent clotting factors. In other words, vitamin K is essential for the synthesis of certain clotting factors in the liver. By blocking the formation of vitamin-K-dependent clotting factors, warfarin prevents blood clots from forming. On the other hand, Xarelto (rivaroxaban) blocks the effects of factor Xa (ten A), a vitamin-K dependent protein, and Eliquis (apixaban) affects the production of thrombin, an enzyme essential for the blood clotting process.

Blood thinners also work by preventing the aggregation of platelets. Antiplatelet drugs prevent the aggregation of platelets in the blood and regulate blood fluidity and reduce the risk of clotting or the formation of unwanted blood clots. Platelets are tiny cells and facilitate the formation of a blood clot.

Commonly prescribed types of blood thinners

Warfarin (Coumadin)

Coumadin is the common brand of warfarin, a vitamin K antagonist. Warfarin is the oldest and still one of the most widely used blood thinners in medical practice. It is an oral anticoagulant that prevents and treats blood clotting. It comes in tablet form and is usually taken once daily. One of the major disadvantages of warfarin is the stringent monitoring requirement of INR (international normalized ratio) and dietary restriction, which can be challenging for many people.

How warfarin works and its effects on clotting factors

This blood thinner works by stopping the activity of the enzyme vitamin K epoxide reductase. This enzyme recycles vitamin K in the liver. Increased levels of vitamin K result in the production of clotting factors.

Warfarin reduces the production of vitamin K-dependent factors such as II, VII, IX, and X, as well as proteins C and S.

Potential side effects

Bleeding

Healthcare research has shown that while warfarin may prevent a harmful blood clot, it tends to cause serious bleeding.

Mild bleeding is characterized by easy bruising, nosebleeds, or bleeding from minor cuts.

Severe bleeding is rare and can be seen in the gastrointestinal tract, brain, or other critical organs.

Medications and foods interactions

Warfarin can interact with prescription, over-the-counter, and herbal medications. Interactions may affect the warfarin's activity and can cause excessive bleeding. Studies have shown that warfarin can interact with antibiotics, antifungal, and anti-inflammatory drugs such as NSAIDs (non-steroidal anti-inflammatory drugs). Leafy green foods high in vitamin K can interfere with warfarin's effectiveness. That’s the reason why a consistent daily intake of vitamin K is crucial for warfarin therapy.

Direct Oral Anticoagulants (DOACs)

Direct Oral Anticoagulants (DOACs) are newer blood thinners. They act directly on clotting factors such as Xa or thrombin. They do not require regular blood tests as compared to warfarin.

Unlike warfarin, DOACs anticoagulant effect is typically predictable and can be taken orally in fixed doses with more predictable anticoagulant effect.

Commonly prescribed DOACs and their uses

Apixaban (Eliquis)

Apixaban, brand name Eliquis, prevents strokes and systemic embolism in non-valvular atrial fibrillation patients. It also prevents and treats deep vein thrombosis (DVT) and pulmonary embolism (PE).

Rivaroxaban (Xarelto)

Rivaroxaban, brand name Xarelto, is indicated in the case of stroke and systemic embolism in non-valvular atrial fibrillation, treatment of DVT, and PE. It also prevents recurrent DVT (deep vein thrombosis) and PE.

Dabigatran (Pradaxa)

Dabigatran, brand name Pradaxa, is usually prescribed for conditions like strokes and systemic embolism.

Edoxaban (Savaysa)

Edoxaban, brand name Savaysa, is also used to treat strokes and embolisms of various types.

These blood thinner pills have a rapid onset of action compared to warfarin. DOACs also have fixed dosing, removing the need for routine INR monitoring. These anticoagulant medicines also reduce the frequency of hospital visits and regular blood tests.

Safety guidelines and potential side effects

DOACs may cause bleeding, gastrointestinal problems like stomach upset and nausea, and may also cause allergic reactions rarely. Prompt reporting of any concerning symptoms to a healthcare provider is essential to stop bleeding.

Low Molecular Weight Heparin (LMWH)

Overview and uses

It is a type of blood thinner derived from unfractionated heparin. Unfractionated heparin has a larger molecular size as compared to LMWH. Small size allows LMWH to show predictable anticoagulant effects. It has a longer duration of action and is used to prevent and treat a blood clot.

Precautions and potential risks

LMWH blood thinner is also associated with an increased risk of bleeding. It can cause prolonged bleeding in case of cuts and injuries. You may also observe blood in the urine and stools. Getting a prompt medical check-up is advisable if you observe unusual bleeding while taking LMWH.

LMWH may cause allergic skin reactions as well as bruising, pain, or irritation at the injection site.

Immediate medical attention should be sought if you suspect difficulty breathing, swelling of the face or throat, rash, or hives.

Antiplatelet agents

Platelets are small, colorless cells found in the blood. They help to form a blood clot and prevent bleeding. Antiplatelet agents prevent the platelets from clumping together, thereby reducing the risk of blood clot formation. They are prescribed to prevent heart attacks, strokes, and other similar conditions.

Commonly used anti-platelet drugs

Aspirin, clopidogrel (Plavix), prasugrel (Effient), and ticagrelor (Brilinta) are some of the commonly prescribed antiplatelet drugs used to treat various cardiovascular events like heart attacks, strokes, percutaneous coronary intervention, or with acute coronary syndrome.

What should you do when taking both blood thinners and antiplatelet drugs?

Some medical conditions require the intake of both blood thinners (anticoagulant medications) and antiplatelet drugs. Healthcare research has revealed the combination may increase the risk of excessive bleeding. Adhere to the prescription instructions of the healthcare provider if you are taking both drugs. Always consult your healthcare provider before stopping your medications to optimize effectiveness and safety. Make sure you keep all of your appointments with primary care physicians and specialists for follow-up and blood work. Always let your dentist know that you are on a blood thinner. Let your doctors and pharmacists know if you have any questions.

Safety guidelines and precautions

Communicate with your healthcare provider regarding the use of blood thinners. To ensure safe and effective treatment, inform healthcare professionals about your medications, including blood thinner prescriptions.

Let your doctor know about any and all medical conditions, allergies, or previous bleeding episodes so they can make informed decisions about your care.

Use a soft toothbrush and waxed dental floss to maintain oral health and hygiene, thereby reducing the risk of gum bleeding.

Signs of serious bleeding include excessive bleeding, blood in the urine or stools, coughing up blood, or severe headaches.

Other complications are allergic reactions, such as difficulty breathing, swelling, or rash.

Seek immediate medical attention at the nearest emergency department if you experience any of these symptoms. If you notice you start to bruise easier, get more frequent nosebleeds, or have prolonged bleeding from minor cuts while taking blood thinners, report them to your healthcare provider, even if they seem minor.

Consult a registered dietitian for dietary recommendations to maintain a balanced and healthy lifestyle while on blood thinners.

When to see a doctor

Call your doctor if you experience signs of excessive bleeding, injury, or trauma, severe allergic reactions (swelling of the face, lips, tongue, or throat), developing blood clots, severe dizziness or fainting, etc.

References