5 WARNINGS AND PRECAUTIONS
5.1 Hemorrhage
Avoid using heparin in the presence of major bleeding, except when the benefits of heparin therapy outweigh the potential risks.
Hemorrhage can occur at virtually any site in patients receiving heparin. Fatal hemorrhages have occurred. An unexplained fall in hematocrit or fall in blood pressure, or any other unexplained symptom should lead to serious consideration of a hemorrhagic event.
Use heparin sodium with caution in disease states in which there is increased risk of hemorrhage, including:
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- Cardiovascular — Subacute bacterial endocarditis. Severe hypertension.
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- Surgical — During and immediately following (a) spinal tap or spinal anesthesia or (b) major surgery, especially involving the brain, spinal cord or eye.
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- Hematologic — Conditions associated with increased bleeding tendencies, such as hemophilia, thrombocytopenia and some vascular purpuras.
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- Gastrointestinal — Ulcerative lesions and continuous tube drainage of the stomach or small intestine.
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- Patients with hereditary antithrombin III deficiency receiving concurrent antithrombin III therapy – The anticoagulant effect of heparin is enhanced by concurrent treatment with antithrombin III (human) in patients with hereditary antithrombin III deficiency. To reduce the risk of bleeding, reduce the heparin dose during concomitant treatment with antithrombin III (human).
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- Other — Menstruation, liver disease with impaired hemostasis.
5.2 Heparin-Induced Thrombocytopenia and Heparin-Induced Thrombocytopenia with Thrombosis
Heparin-induced thrombocytopenia (HIT) is a serious immune-mediated reaction. HIT occurs in patients treated with heparin and is due to the development of antibodies to a platelet Factor-4-heparin complex that induce in vivo platelet aggregationHIT may progress to the development of venous and arterial thromboses, a condition referred to as heparin-induced thrombocytopenia with thrombosis (HITT). Thrombotic events may also be the initial presentation for HITT. These serious thromboembolic events include deep vein thrombosis, pulmonary embolism, cerebral vein thrombosis, limb ischemia, stroke, myocardial infarction, mesenteric thrombosis, thrombus formation on a prosthetic cardiac valve, renal arterial thrombosis, skin necrosis, gangrene of the extremities that may lead to amputation, and possibly death.
If the platelet count falls below 100,000/mm3 or if recurrent thrombosis develops, promptly discontinue heparin, evaluate for HIT and HITT, and, if necessary, administer an alternative anticoagulant. HIT or HITT can occur up to several weeks after the discontinuation of heparin therapy. Patients presenting with thrombocytopenia or thrombosis after discontinuation of heparin sodium should be evaluated for HIT or HITT.
HIT can occur up to several weeks after the discontinuation of heparin therapy. Patients presenting with thrombocytopenia or thrombosis after discontinuation of heparin should be evaluated for HIT.
5.3 Thrombocytopenia
Thrombocytopenia in patients receiving heparin has been reported at frequencies up to 30%. It can occur 2 to 20 days (average 5 to 9) following the onset of heparin therapy. Obtain platelet counts before and periodically during heparin therapy. If the count falls below 100,000/mm3 or if recurrent thrombosis develops, promptly discontinue heparin, evaluate for HIT and HITT, and, if necessary, administer an alternative anticoagulant [see Warnings and Precautions (5.2)].
5.4 Heparin Resistance
Increased resistance to heparin is frequently encountered in fever, thrombosis, thrombophlebitis, infections with thrombosing tendencies, myocardial infarction, cancer and in postsurgical patients.
5.5 Hypersensitivity Reactions
Patients with documented hypersensitivity to heparin should be given the drug only in clearly life-threatening situations. Because Heparin Sodium in Sodium Chloride Injection is derived from animal tissue, it should be used with caution in patients with a history of allergy.
5.6 Increased Risk of Bleeding in Older Patients, Especially Women
A higher incidence of bleeding has been reported in patients, particularly women, over 60 years of age [see Use in Specific Populations (8.5)].
5.7 Laboratory Tests
Periodic platelet counts, hematocrits, and tests for occult blood in stool are recommended during the entire course of heparin therapy, regardless of the route of administration.