Drugs Used in Disorders of Coagulation

Drugs Used in Disorders of Coagulation 

Hemostasis refers to the finely regulated dynamic process of main-taining fluidity of the blood, repairing vascular injury, and limiting blood loss while avoiding vessel occlusion (thrombosis) and inade-quate perfusion of vital organs. Either extreme—excessive bleeding or thrombosis—represents a breakdown of the hemostatic mecha-nism. Common causes of dysregulated hemostasis include heredi-tary or acquired defects in the clotting mechanism and secondary effects of infection or cancer.

CASE STUDY

A 25-year-old woman presents to the emergency department complaining of acute onset of shortness of breath and pleu-ritic pain. She had been in her usual state of health until 2 days prior when she noted that her left leg was swollen and red. Her only medication was oral contraceptives. Family history was significant for a history of “blood clots” in multiple members of the maternal side of her family. Physical exami-nation demonstrates an anxious woman with stable vitalsigns. The left lower extremity demonstrates erythema and edema and is tender to touch. Ultrasound reveals a deep vein thrombosis in the left lower extremity; chest computed tomography scan confirms the presence of pulmonary emboli. Laboratory blood tests indicate elevated D-dimer levels. What therapy is indicated acutely? What are the long-term therapy options? How long should she be treated? Should this individual use oral contraceptives

CASE STUDY ANSWER

This patient has pulmonary embolism secondary to a deep venous thrombosis (DVT). Immediate therapy with intrave-nous heparin is indicated. If hemodynamic instability or pulmonary function deteriorates, suggesting further embo-lization to the lung, percutaneous placement of an inferior vena cava filter may be considered. Long-term therapy with warfarin is traditional standard of care, using a target of 2–3 international normalized ratio. This patient should be advised to use other methods of contraception.