How Do Anticoagulants Work?

Anticoagulants also called blood thinners are drugs that are used to treat and prevent blood clots. They interrupt the process involved in the formation of blood clots and work by targeting the clotting factors such as thrombin, fibrin, and vitamin K. The most commonly prescribed anticoagulant is warfarin and the use of newer anticoagulants (rivaroxaban, dabigatran, apixaban, edoxaban) is becoming increasingly common.

Thrombin is a clotting factor that is formed from prothrombin. Thrombin burst (excess formation of thrombin) is feedback for the formation of fibrin from fibrinogen. Thrombin and fibrin are required for the formation of a clot to stop bleeding caused by any injury. Anticoagulant drugs focus on limiting the generation of thrombin and inhibit the activity of thrombin that exists. Vitamin K is required for the generation of thrombin, so vitamin K antagonists inhibit thrombin formation. Heparin acts directly on factor Xa and inhibits thrombin formation. Dabigatrin, an anticoagulant drug directly inhibits thrombin formation.

Anticoagulants are used to treat and prevent blood clots, the most common cause being a deep vein thrombosis (a blood clot forms in a deep vein, usually in the legs) and/or pulmonary embolism (one or more arteries in the lungs become blocked by a blood clot). Other conditions where anticoagulants may be used include:

• Myocardial infarction (heart attack)
• Unstable angina (a condition in which the heart does not get enough blood flow and oxygen)
• Rheumatic heart disease (a condition in which the heart valves have been permanently damaged by rheumatic fever)
• Stroke
• Atrial fibrillation (an irregular, often rapid heart rate that commonly causes poor blood flow)
• Cerebrovascular disease
• Vascular surgery

The most common side effects of anticoagulants include:

• Bleeding
• Chest pain, noncardiac
• Passing blood in urine and feces
• Severe bruising
• Nose bleeds and bleeding from gums
• Vomiting blood (hematemesis)
• Coughing up blood (hemoptysis)
• Dizziness
• Shortness of breath
• Headache
• Prolonged bleeding after a cut or a procedure
• Changes in hepatic enzymes causing jaundice
• Injection site itching
• Diarrhea or constipation

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Drug names include:

• Acova
• Angiomax
• Angiomax RTU
• Apixaban
• Argatroban
• Bivalirudin
• Coumadin
• Dabigatran
• Dalteparin
• Eliquis
• Enoxaparin
• Fragmin
• Heparin
• Jantoven
• Lovenox
• Pradaxa
• Rivaroxaban
• Warfarin
• Xarelto