Warfarin - Its History, Uses And Side Effects.

Warfarin is an anticoagulant , which in turn is a substance that actually prevents blood from clotting. It is often prescribed to people who have an increased tendency for thrombosis, those who have suffered blood clots or for the thinning of the blood for people who have had heart replacement valves or stents.

It was initially marketed as a pesticide against rats and mice and is still popular for this purpose. A few years after its introduction, warfarin was found to be effective and relatively safe for preventing thrombosis and was approved as a medication in the early 1950’s.

An incident took place in 1951, where a US Army inductee unsuccessfully attempted suicide with multiple doses of warfarin, { which at that time was being used as a pesticide } and recovered fully being treated with vitamin K { which was then known as a specific antidote} This was when studies began in the use of warfarin as a therapeutic anticoagulant. A famous early recipient of warfarin was the US president Dwight Eisenhower, who was prescribed the drug after having a heart attack in 1955.

Warfarin works by slowing down the process in the liver that uses vitamin K to make certain proteins { clotting factors } that cause clotting. It usually takes several days before warfarin becomes completely effect, therefore heparin or LMWH is given concurrently until the warfarin takes effects.

Warfarin patients need to have their blood tested regularly to see how well the drug is working and to be monitored for safety also. The blood test measures how long it takes blood to clot. This results are reported with an INR number{ International Normalized Ratio } that converts all clotting times to the same number. People who are not on warfarin have an INR between 0.8 and 1.2, whereas most patients on warfarin have an INR between 2 and 3, of which is considered to be their therapeutic range.

Foods that are high in vitamin K can affect blood clots, therefore affecting the way that warfarin protects you. This is often found in foods such as soybean, canola oils, spinach and broccoli. Garlic and liquorice may also interact with warfarin, therefore it would be advisable to discuss this with your doctor if you eat a lot of these foods.

Cranberries and cranberry juice can effect the way that warfarin works and increase your risk of bleeding, however an occasional glass of cranberry juice is unlikely to injure you, but you should avoid drinking it regularly. The occasional drink of alcohol shouldn't create a problem, but excessive drinking and binge drinking increases your bleeding risk.

Skin conditions, such as hives, rash or itching.

Swelling of the face, throat, mouth, hands, feet or legs.

Bruising that comes about without an injury you remember.

Nausea, vomiting or diarrhoea.

Joint and muscles aches, with difficulty moving.

Fever, or flu like symptoms.

Chest pain or pressure.

Severe bleeding, or bleeding from the rectum.

Gas / flatulence.

Feeling cold.

Fatigue.

Hair loss.

Changes in the way food tastes.

Always advisable to consult your doctor if any of these side effects occur.