Anticoagulants

Heparin

In the acute period of a clot-related event (e.g. stroke, heart attack, vein thrombosis, pulmonary embolism) patients will receive heparin (intravenous or in the form of injections under the skin (subcutaneous)). They will then need transition to an anticoagulant that can be taken orally (by mouth).

Heparin is also used prophylactically after major surgical procedures, to prevent blood clot formation at the veins of the legs.

Warfarin (Coumadin)

Warfarin is the most frequently used anticoagulant. Warfarin decreases the body’s ability to form blood clots by blocking Vitamin K that is essential for the regulation of some clotting reactions. If you've had a recent heart attack or stroke, arterial or venous thrombosis or pulmonary embolism, your doctor will likely recommend you take warfarin unless you have a serious allergy or history of bleeding. Warfarin is also recommended as a prophylactic agent for medical conditions known to promote blood clots such as atrial fibrillation and mechanical heart valves.

In order for your doctor to adjust the dose of warfarin, it will be necessary for you to have frequent blood tests, at least in the beginning. Once the desired blood levels have been achieved blood tests will need to be repeated approximately once a month. The International Normalized Ratio (INR) test measures how fast your blood is clotting. In the majority of cases the target INR is between 2 and 3, sometimes 3 to 4. Illness, diet, medication changes, and physical activities may affect your INR.

The major side effect of taking Coumadin, as for any blood thinner, is bleeding the most serious one being hemorrhagic stroke or gastrointestinal bleeding.

If you're taking warfarin and need a surgical procedure or dental work, be sure to tell the surgeon or dentist that you are on warfarin and the reason you take it. There is a risk of excessive bleeding during surgery and you may be asked to discontinue it for 5-7 days; however don't stop taking it without talking to both your doctor who recommended warfarin and your surgeon or dentist.

Tips for Blood Thinner Users (PDF download)

Diet Guide for Warfarin (Coumadin) Users (PDF download)

Novel Anticoagulants

Four novel oral anticoagulants including apixaban (Eliquis), dabigatran (Pradaxa), Edoxaban (Savaysa), Rivaroxaban (Xarelto) are now available for treating some conditions where there is a risk of blood clots’ forming or when clot has already been formed (e.g. atrial fibrillation, deep venous thrombosis, pulmonary embolism). These drugs may be recommended as an alternative to warfarin/coumadin to avoid interactions with other treatments, food or alcohol. The great advantage of these new pills is that, unlike warfarin, they do not need to be monitored with blood tests (INR). Research suggests they are at least as effective as warfarin, and possibly safer.

The major side effect of taking any of these blood thinners (as it is with coumadin) is bleeding the most serious one being hemorrhagic stroke or gastrointestinal bleeding. Other side effects may include stomach disturbances but these are usually minor.

If you're taking any of these new blood thinners and need a surgical procedure or dental work, be sure to tell the surgeon or dentist that you are on it and the reason you take it. There is a risk of excessive bleeding during surgery and you may be asked to discontinue it for 5-7 days; however don't stop taking it without talking to both your doctor who recommended this pill and your surgeon or dentist.

Tips for Blood Thinner Users (PDF download)