Risk for Thrombosis Persists After Discontinuation of Heparin Therapy

[الدكتور أحمد باذيب]

	December 11, 2006 — The US Food and Drug Administration (FDA) and Baxter Healthcare Corp have warned healthcare professionals regarding the risk for delayed-onset heparin-induced thrombocytopenia (HIT) in patients receiving heparin sodium injection. HIT is a serious antibody-mediated reaction that results from irreversible platelet aggregation and can lead to the development of heparin-induced thrombocytopenia and thrombosis (HITT). Patients presenting with thrombocytopenia or thrombosis within several weeks of discontinuing heparin therapy should be evaluated for HIT and HITT, according to an alert sent Friday from MedWatch, the FDA's safety information and adverse event reporting program. HITT can present as thromboembolic events, including deep vein thrombosis (DVT), pulmonary embolism (PE), cerebral vein thrombosis, limb ischemia, stroke, myocardial infarction, mesenteric thrombosis, renal arterial thrombosis, skin necrosis, gangrene of the extremities that can lead to amputation, and possibly death. Heparin sodium injection is indicated for the prophylaxis and treatment of venous thrombosis, PE, and peripheral arterial embolism; treatment of atrial fibrillation with embolization; diagnosis and treatment of acute and chronic consumptive coagulopathies; and for the prevention of clotting in arterial and cardiac surgery. Heparin is also indicated for use as an anticoagulant in blood transfusions, extracorporeal circulation, dialysis procedures, and blood samples for laboratory purposes. A low-dose regimen may be used to prevent postoperative DVT and PE in patients undergoing major abdominothoracic surgery and those at risk for developing thromboembolic disease due to other reasons. During treatment, thrombocytopenia of any degree should be closely monitored; if platelet counts decrease to less than 100,000/mm3, heparin should be promptly discontinued and alternative anticoagulant therapy considered if needed. Adverse events potentially related to heparin therapy should be reported to the FDA's MedWatch reporting program by phone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at http://www.fda.gov/medwatch, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787