ORAL THERAPY, NEW TRENDS IN THE MANAGEMENT OF DEEP VENOUS THROMBOSIS (D.V.T) AND PULMONARY EMBOLISM (P.E)

Abstract

SUMMARY T he aim of this essay was to discuss the role of new oral anticoagulant in treatment of deep venous thrombosis (DVT) and pulmonary embolism (PE) in comparison with the traditional anticoagulants. Thromboembolic disorders are a major cause of morbidity and mortality worldwide. Venous thromboembolism (VTE), which includes both deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most common cardiovascular disorder after ischaemic heart disease and stroke, and is estimated to contribute to about 10% of all deaths that occur in the hospital. Now three oral anticoagulant drugs are FDA-approved in treatment and prevention of recurrence of deep venous thrombosis (DVT) and pulmonary embolism (PE), these drugs are (rivaroxiban, dabigatran, apixaban), the fourth one (edoxaban) still under Food and Drug Administration (FDA) review. Virchow’s Triad of which include (stasis, endothelial dysfunction and hypercoagulability) does not completely describe the complete pathophysiology of deep venous thrombosis in most patients. Acute pulmonary embolism (PE) results in an abrupt increase in pulmonary vascular resistance and right ventricular afterload through hypoxemia, direct physical obstruction, and release of pulmonary artery vasoconstrictors. In order to improve survival rate, prevent complications, avoid recurrence and reduce costs, the incidence of venous thromboembolism must be decreased. To reduce VTE occurance, persons who are at risk for venous thrombo embolism must first be clearly identified. Independent risk factors for venous thromboembolism include: (patient age, surgery, trauma, bedridden for along time, active malignancy with or without concurrent treatment with chemotherapy, transvenous pacemaker or central vein catheterization, varicose veins, prior superficial vein thrombosis, and neurological disease with extremity paresis); patients who have chronic liver disease have a reduced risk for VTE. Depending upon the risk for deep venous thrombosis, different preventive measures are used. Calf exercises and walking reduce venous stasis because the contraction of leg muscles compress the veins and pump blood towards the heart. Warfarin is an effective drug for the reduction of thromboembolic events in atrial fibrillation (AF). Over the last 7 decades, warfarin use has been associated with a lot of clinical problems for patients and healthcare providers (bleeding, visits to emergency, hospitalizations/costs, length of stay, multiple international normalized ratio (INR) tests, variability in response, commercial variability on generics and others. Switching warfarin formulations was found to predispose patients with AF to a higher risk of bleeding compared to remaining on a single product of the drug. In the last few years, novel oral anticoagulants or NOACs (including apixaban, edoxaban, rivaroxaban which are factor Xa inhibitors, and dabigatran which is direct thrombin inhibitor) have been used in treatment of patients with non-valvular atrial fibrillation as suitable alternatives to the warfarin and analogues to prevent stroke and venous thromboembolism (VTE).