Warfarin: The anticoagulant

Some medical conditions require thinning of the blood in order to prevent formation of dangerous blood clots in veins and arteries, which can be life-threatening. These medical conditions range from atrial fibrillation that causes irregular heartbeat; to mechanical heart valve and after a heart attack. (National Institutes of Health, 2013).

Cardiovascular diseases can encourage the formation of intravascular clots-inside blood vessels, especially if the latter are being damaged by arteriosclerosis which is the hardening of the arteries that occurs at old age. When arteries are damaged, resistance to blood flow increase so platelets tend to stick together as the blood circulation goes slower. The formation of a blood clot inside an unbroken vessel can potentially travel in the bloodstream targeting a smaller vessel thus blocking the blood flow to a vital organ; this condition is known as embolism and it is a medical emergency. As a preventative measure, patients who are at high risk of developing intravascular blood clots as a result of all of the above mentioned conditions are often prescribed a pharmaceutical drug called “Warfarin”. This drug belongs to a class of drugs called anticoagulants, or blood thinners. (Tortora & Derrickson, 2011).

The chemical structure of the drug and its systematic name are the following:

4hydroxy-3-(3-oxo-1-phenylbutyl)-2H-chromen-2-one. (Royal Society of Chemistry, 2013).

Gerard J. Tortora and Bryan Derrickson explained that the drug Warfarin antagonises the effects of vitamin K which is produced naturally by the Bacteria that live in the large intestine; Vitamin K plays a major role in blood clotting. The anticoagulant drug ‘Warfarin’ slows the production of vitamin K which increases the time it takes for the blood to clot, thus blocking the synthesis of four important clotting factors: II, VII, IX and X.

The National Institutes of Health highlighted that food containing large amounts of vitamin K can affect the way this drug works; therefore patients who are on Warfarin need to monitor their intake of vitamin K rich food, of which large amounts is restricted. A regular blood test is carried out on such patients, in order to monitor their blood tendency to clot so that the dosage of Warfarin can be adjusted accordingly. These values are measured in international units (INR).

Like any pharmaceutical drug, Warfarin does have side effects and probably the most dangerous of all is severe bleeding, given the fact that the drug blocks the synthesis of four clotting factors as mentioned before. Apart from that, the national institutes of Health cited some side effects associated with the ingestion of the drug, these include: Bloating, abdominal pain, gas, loss of hair, change in the way things taste, and feeling cold. Some warning symptoms which require medical assistance are: Difficulty breathing or swallowing, chest pain or pressure, vomiting, yellowing of the skin or eyes, and infection.

According to the royal pharmaceutical society, although Warfarin has been used for years, some patients cannot tolerate Warfarin therapy for many reasons including allergies, contraindications, inability to adhere to regular monitoring, and inability to stabilize their (INR) values. Therefore, alternative drugs will be considered for those with atrial fibrillation.