Coumarin derivatives are widely used as oral anticoagulants for the prophylaxis and treatment of venous thromboembolism. The indications for the most commonly prescribed of these medications in North America, warfarin sodium, has recently been expanded with the demonstration of its efficacy in preventing strokes in patients with nonrheumatic atrial fibrillation.1 Another clinical trial2 has shown that the drug is useful in preventing recurrent myocardial infarction, and studies are currently being conducted to determine the efficacy of low-intensity warfarin in combination with aspirin as primary or secondary prophylaxis for this disorder.
The major complication of oral anticoagulants is hemorrhage, but this has declined in recent years with the use of lower intensity schedules of warfarin for many clinical indications that are equivalent to higher intensity regimens in preventing thrombosis. At the same time, a system has been implemented to standardize monitoring of oral anticoagulation between clinical laboratories. This is
Bauer KA. Coumarin-Induced Skin Necrosis. Arch Dermatol. 1993;129(6):766-768. doi:10.1001/archderm.1993.01680270104015