Anticoagulants are medicines that help prevent blood clots. They’re given to people at a high risk of getting clots, to reduce their chances of developing serious conditions. A blood clot is a seal created by the blood to stop bleeding from wounds. While they’re useful in stopping bleeding, they can block blood vessels and stop blood flowing to organs such as the brain, heart or lungs if they form in the wrong place.
Anticoagulants work by interrupting the process involved in the formation of blood clots. They’re sometimes called “blood-thinning” medicines, although they don’t actually make the blood thinner.
Why are they used?
An anticoagulant medicine is used in patients to prevent blood clots from forming in veins, arteries, the heart, and the brain of a patient. For example, if the clot travels to the patient’s heart it can cause a heart attack or if one forms in the brain it may cause a stroke or TIA (mini-stroke, transient ischemic attack).
Examples of diseases and health conditions that require treatment with anticoagulants to reduce the risk of clots forming, or are used to prevent life-threatening problems include:
- Deep vein thrombosis (DVT)
- Heart attack
- For the prevention or treatment of:
- Pulmonary embolism
- Blood clots within venous and arterial catheters
- Stent thrombosis
- Blood clots during atrial fibrillation (afib) treatment
What are the types of blood thinners?
There are two main types of blood thinners. Anticoagulants such as heparin or warfarin (also called Coumadin) slow down your body’s process of making clots. Antiplatelet drugs, such as aspirin, prevent blood cells called platelets from clumping together to form a clot.
How to take anticoagulants
Anticoagulants are given either in oral form or by injection. Most injectable forms are administered in the hospital. The type of anticoagulant prescribed depends upon the condition being prevented. Oral anticoagulants are used to ward off clot formation in patients with heart-valve replacement, atrial fibrillation, or other heart diseases, and in patients with phlebitis (inflammation of a vein). Injectable anticoagulants are often used to prevent blood clots before or after major surgery, such as knee or hip replacement.
Your doctor or nurse should tell you how much of your anticoagulant medicine to take and when to take it. Most people need to take their tablets or capsules once or twice a day with water or food.
The length of time you need to keep taking your medicine for depends on why it’s been prescribed. In many cases, treatment will be lifelong. If you’re unsure how to take your medicine, or are worried that you missed a dose or have taken too much, check the patient information leaflet that comes with it or ask your GP, anticoagulant clinic or pharmacist what to do.
Common side effects of anticoagulants include stomach upset, loss of appetite, bloating, and diarrhea. If the dosage is too high, blood may be seen in the urine or stool or around the gums, or frequent nosebleeds may occur. These side effects, as well as easy bruising, dark stools, itching or hives, vomiting of blood, or back pain, should be reported to a healthcare professional immediately.
Many foods and drugs can increase or decrease the action of anticoagulants, especially warfarin. Patients should be aware of the foods that can interfere with anticoagulants and should avoid eating them often or in large quantities. Newer agents, however, have fewer dietary restrictions. Patients should inform their pharmacist and doctors that they are taking an anticoagulant. Precautions must be taken prior to certain medical and dental procedures in patients taking anticoagulants. Many commonly used prescription and OTC medicines, such as antibiotics and pain relievers, can affect the action of anticoagulants. Vitamin K, vitamin E, fish oil, herbal products, smoking, and alcohol can also affect anticoagulant activity.
Anticoagulant (Blood Thinner) Safety
When you take a blood thinner, follow directions carefully. Blood thinners may interact with certain foods, medicines, vitamins, and alcohol. Make sure that your health care provider knows all of the medicines and supplements you are using. You will probably need regular blood tests to check how well your blood is clotting. It is important to make sure that you’re taking enough medicine to prevent clots, but not so much that it causes bleeding.
Anticoagulants should be taken at the same time each day, and patients should understand what to do if they miss a dose. Brand-name and generic forms of oral anticoagulants are not always identical in their effect, especially between countries. For this reason, it is extremely important to take along a supply of anticoagulant medication when traveling abroad.