Coumadin (Warfarin) 1mg Tablets

Coumadin general information

What is Coumadin used for?

Coumadin tablets 1mg are used for treatment and prevention of blood clot formation (thrombosis) in conditions that could be life threatening. Blood clot formation is a normal response to blood vessel damage to stop bleeding. However, a blood clot (thrombus) can also form in situations where blood flow is disturbed such as if a blood vessel becomes blocked due to fatty deposits, a condition known as atherosclerosis. Also if blood flow slows down due to reduced mobility, heart failure and atrial fibrillation (irregular heart beat). If a clot becomes detached from the vessel it can travel through the circulation and this is a thromboembolism. Blood clot formation in the veins is called a venous thrombosis or deep vein thrombosis, because they usually occur in the deep veins of the leg or pelvis and can become lodged in the lungs causing a pulmonary embolism. If a clot form in an artery or in the heart, it can block the blood supply to the heart tissue and cause a myocardial infarction (heart attack); or it can travel to the brain and cause a stroke. Coumadin tablets 1mg are used to treat thrombosis and thromboembolisms in a variety of condition, particularly in those at risk, such as after a mini stroke (transient ischemic attack) or with atrial fibrillation; also to prevent an existing thrombus from causing fatal consequences. Coumadin tablets 1mg may be used alone or in conjunction with a rapidly acting anticoagulant like heparin.

How does Coumadin work?

Coumadin tablets 1mg contain warfarin, which is an anticoagulant that is used to treat and prevent blood clot formation (thrombosis), sometimes known as a “blood thinner”. Warfarin in Coumadin tablets 1mg acts by inhibiting the production of Vitamin K dependent blood coagulation factors. The first stage in the formation of a blood clot is the clumping or aggregation of small blood cells called platelets. The coagulation cascade is then activated either in response to injury, such as a cut, or to internal damage to a blood vessel surface. This triggers the activation of a series of coagulation factors, which are mostly enzymes, resulting in the generation of plug formed by a fibrous protein (fibrin) that combines with the clump of aggregated platelets and becomes a blood clot or thrombus. Several of the coagulation factors, which are made in the liver, are dependent on Vitamin K as a cofactor in their production and include factors VII, IX, X and II. Warfarin in Coumadin tablets 1mg inhibits the synthesis of these Vitamin K dependent coagulation factors, which ultimately prevents thrombus formation. This anticoagulant effect can take up to 3 days to be apparent, while existing coagulation factors are used up and production of new coagulation factors is inhibited. Although Coumadin tablets 1mg prevent thrombosis, they do not reverse a thrombus that has already formed but do prevent it becoming larger, which could have fatal results if it became dislodged and travelled to the heart (heart attach) or brain (stroke) or lungs (pulmonary embolism).

What does Coumadin contain?

Coumadin tablets 1mg contain the active ingredient warfarin, an anticoagulant that inhibits the production of vitamin K dependent blood coagulation factors. They also contain lactose anhydrous, starch – tapioca, stearic acid, magnesium stearate, amaranth, quinoline yellow indigo carmine.

What doses of Coumadin are available?

Coumadin tablets are available in three doses:

• 1mg (beige/tan colour)
• 2mg (lavender colour)
• 5mg (green colour)

Treating thrombosis with Coumadin

Coumadin tablets 1mg contain warfarin, which is an anticoagulant sometimes known as a “blood thinner” and is used for treatment and prevention of blood clot formation (thrombosis) that could be life threatening. Blood clot formation is a normal response to blood vessel damage to stop bleeding and begins with clumping or aggregation of small blood cells called platelets, followed by activation of the coagulation cascade, in which series of coagulation factors, which are mostly enzymes and several of which are dependent on Vitamin K as a cofactor in their production and include factors VII, IX, X and II. The final stage of the coagulation cascade is the generation of fibrin plug that combines with the clump of aggregated platelets and becomes a blood clot or thrombus. In situations where blood flow is disturbed or slows down, a blood clot can form and if it becomes detached from the vessel it can travel through the circulation as a thromboembolism. This can happen due to fatty deposits in the vessel wall, a condition known as atherosclerosis; also due to reduced mobility, heart failure and atrial fibrillation (irregular heart beat). Blood clot formation in the veins is called a venous thrombosis or deep vein thrombosis, because they usually occur in the deep veins of the leg or pelvis and can become lodged in the lungs causing a pulmonary embolism. If a clot forms in an artery or in the heart, it can block the blood supply to the heart tissue and cause a myocardial infarction (heart attack); or it can travel to the brain and cause a stroke. Coumadin tablets 1mg are used to treat thrombosis and thromboembolisms in a variety of condition, particularly in those at risk, such as after a mini stroke (transient ischemic attack) or with atrial fibrillation; also to prevent an existing thrombus causing fatal consequences. The anticoagulant effect of Coumadin tablets 1mg can take up to 3 days to be apparent, while existing coagulation factors are used up and production of new coagulation factors is inhibited.

What are the side effects of Coumadin?

The most commonly reported side effects when taking Coumadin tablets 1mg include: haemorrhage (excessive bleeding) from any tissue or organ, including the brain, gastrointestinal system and can cause a variety of symptoms, including headache, bruising, blood in the urine, nosebleeds, difficulty breathing; purple toes syndrome (dislodged cholesterol deposits which become deposited in the toes). Other side effects include: gastrointestinal upset (stomach pain, nausea, diarrhoea), fever, rash, dermatitis, alopecia, (hair loss), cholestatic hepatic injury (drug induced liver damage), tissue necrosis (cell death).

When should Coumadin not be used?

You should not use Coumadin tablets 1mg if you:

• are allergic to warfarin or any ingredients in Coumadin
• are pregnant or are breastfeeding
• have kidney or liver disease
• have tendencies to increased bleeding or are at risk of haemorrhage (excessive bleeding) due to a condition such as recent ischaemic stroke, bacterial endocarditis, previous gastrointestinal bleeding
• have recently had a major surgery or will be having major surgery with risk of severe bleeding within 72 hours
• have a condition which may interact with the action of Coumadin by increasing or decreasing the clotting time, including, moderate or severe hypertension, thyroid disease, serious heart disease, certain gastrointestinal problems, collagen disease, increased body temperature, poor nutrition
• have a deficiency in the coagulation factor Protein C as this increases risk of necrosis when using Coumadin
• have a diet that is high in vitamin K, such large amounts of green leafy vegetable, drink cranberry juice or alcohol, as these may reduce the effect of Coumadin
• are taking medicines that interact with Coumadin, including: NSAIDs including aspirin, other anticoagulants like heparin and dabigatran for treating thrombosis, antiplatelet drugs like eptifibatide and clopidogrel for preventing heart attack, streptokinase for treating heart attack, sulfinpyrazone for gout, antibiotics like erythromycin and metronidazole, antifungals like ketoconazole and griseofulvin, omeprazole for reflux, antiarrhythmics like amiodarone and propafenone, some cholesterol lowering drugs including statins, fibrates and cholestyramine, barbiturates, anticonvulsants like primidone and carbamazepine, phenytoin and phenobarbital, ritonavir for HIV, SSRI and SNRI antidepressants, antihistamines, paracetamol for a long period, some anti-cancer drugs like capecitabine and tamoxifen, antidiabetic drugs like chlorpropamide and tolbutamide, St John’s Wort

What medications interact with Coumadin?

Several medications interact with Coumadin tablets 1mg and should either not be taken while you are taking Coumadin or only after discussion and instruction from your doctor:

• Drugs that increase risk of bleeding with Coumadin: NSAIDs including aspirin, other anticoagulants like heparin and dabigatran for treating thrombosis, antiplatelet drugs like eptifibatide and clopidogrel for preventing heart attack, streptokinase treating for heart attack Sulfinpyrazone for gout
• Drugs that affect Coumadin: NSAIDs including aspirin, other anticoagulants like heparin and dabigatran for treating thrombosis, antiplatelet drugs like eptifibatide and clopidogrel for preventing heart attack, treating heart attack sulfinpyrazone for gout, streptokinase for treating for heart attack, antibiotics like erythromycin and metronidazole, antifungals like ketoconazole and griseofulvin,, omeprazole for reflux, antiarrhythmics like amiodarone and propafenone, some cholesterol lowering drugs including statins, fibrates and cholestyramine, barbiturates, anticonvulsants like primidone and carbamazepine, ritonavir for HIV, SSRI and SNRI antidepressants, antihistamines, paracetamol for a long period, some anti-cancer drugs like capecitabine and tamoxifen, St John’s Wort
• Drugs that are affected by Coumadin: anticonvulsants like phenytoin and Phenobarbital, antidiabetic drugs like chlorpropamide and tolbutamide

How should Coumadin be taken?

You should take your Coumadin tablets 1mg, swallowed whole, with or without food once daily at the same time each day. The dose you take will be individualised depending on your response to warfarin in Coumadin tablets 1mg, as determined by a blood test called the prothrombin time test (PT), which measures how long your blood takes to clot. The test may vary depending on where you have it done but is standardised by the International Normalised Ratio, introduced by the World Health Organisation to control the measurement of coagulation. You will be regularly monitored and your dose may be adjusted until your clotting times have stabilised. You should continue to take your Coumadin tablets 1mg for as long as recommended by your doctor, which will be for as long as you are at risk of thrombosis.

How long should you take Coumadin?

You should continue to take your Coumadin tablets 1mg for as long as recommended by your doctor, which will be for as long as you are at risk of thrombosis.

Missed dose of Coumadin

If you miss a dose of Coumadin tablets 1mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.

How should Coumadin be stored?

You should store your Coumadin below 30°C in a cool dry place.