Prophylaxis of embolism in rheumatic heart disease & atriall fibrillation.[21]

Prophylaxis and treatment of venous thrombosis, pulmonary embolism & transient ischaemic attacks.[21]

Prophylaxis of embolisation in rheumatic heart disease and atrial fibrillation[1]

Prophylaxis after insertion of prosthetic heart valve[1]
Prophylaxis and treatment of venous thrombosis and pulmonary embolism[1]

The route of administration is oral and intravenous.

The following dose is for adult with congestive heart failure. The initial dose is 2 to 5mg once a day for 1 to 2 days. Then, adjust the dose according to results of the International Normalized Ratio (INR) or prothrombin time (PT). The usual maintenance dose is 2 to 10 mg once a day.[29]

• Haemorrhage[1]        
• pain at injection site[1]
• alopecia[1]
• hypersensitivity[1]
• diarrhea[1]
• skin necrosis[1]
• increase in liver enzymes ie ALT & AST1
• nausea[1]
• vomiting. [1]

i. Warfarin – metronidazole
The effect of warfarin is increased when taken with metronidazole. May lead to bleeding if the dosage of warfarin is not reduced appropriately. This due to fact that metronidazole inhibit metabolism of Warfarin, results in increase and prolonged effect of warfarin[4]

ii. Warfarin-Paracetamol
Frequent usage of paracetemol with warfarin may lead to upper gastrointestinal bleeding. [4]

iii. Warfarin- Food
Usage of warfarin with food or supplements that rich in Vitamin K content will reduce effect of warfarin[5]

iv.Warfarin-Herbal Remedies
Warfarin when taken with medicinal garlic or herbal tea( Lycium barbarum) increased anticoagulant effect of warfarin and can lead to bleeding[4]

It can be given via IV or orally. When rapid action is required, dose of 10mg daily 2 days can be used. In many cases, 5mg dose is enough. Less than 5mg daily may be applied for elderly and people with higher risk of bleeding. [8]

Necrosis of skin and soft tissue can occur ; features include localized painful skin lesion. [9]

Incidence of haemorrhage is present in prolong treatment but risk associated with age is very low but intracranial bleeding is related to age. [10]

Not to be used for Pregnant woman and those want to get pregnant. Taking warfarin during pregnancy can causes birth defects and abortion2.Warfarin and even other oral anti-coagulant should be avoided in pregnancies, as these agents causes fetal hemorrhage even when maternal Prothrombin (PT) values are in therapeutic range[2]

High risk of Skin Necrosis with use of warfarin in patient having protein C or protein S defiency. [2]

To be avoided in kidney patient having creatinine clearance less than 10ml/minute[1]

Not to be used in patients with severe hypertension[3]

Not to be used in patients with bacterial endocarditis[3]

Not to be used in patients with peptic ulcer[3]