warnings
WARNINGS Heparin is not intended for intramuscular use. Fatal Medication Errors Do not use Heparin Sodium Injection as a “catheter lock flush” product. Heparin Sodium Injection is supplied in sterile syringes that contain a highly concentrated solution of 5,000 units in 0.5 mL. Fatal hemorrhages have occurred in pediatric patients due to medication errors in which 1 mL Heparin Sodium Injection vials were confused with 1 mL “catheter lock flush” vials. Carefully examine all Heparin Sodium Injection vials and cartridges to confirm the correct product choice prior to administration of the drug. Hypersensitivity Patients with documented hypersensitivity to heparin should be given the drug only in clearly life- threatening situations (See ADVERSE REACTIONS, Hypersensitivity ). Hemorrhage Hemorrhage can occur at virtually any site in patients receiving heparin. An unexplained fall in hematocrit, fall in blood pressure or any other unexplained symptom should lead to serious consideration of a hemorrhagic event. Heparin sodium should be used with extreme caution in disease states in which there is increased danger of hemorrhage. Some of the conditions in which increased danger of hemorrhage exists are: Cardiovascular — Subacute bacterial endocarditis, severe hypertension. Surgical — During and immediately following (a) spinal tap or spinal anesthesia or (b) major surgery, especially involving the brain, spinal cord, or eye. Hematologic — Conditions associated with increased bleeding tendencies, such as hemophilia, thrombocytopenia, and some vascular purpuras. Gastrointestinal — Ulcerative lesions and continuous tube drainage of the stomach or small intestine. Other — Menstruation, liver disease with impaired hemostasis. Coagulation Testing When heparin sodium is administered in therapeutic amounts, its dosage should be regulated by frequent blood coagulation tests. If the coagulation test is unduly prolonged or if hemorrhage occurs, heparin sodium should be promptly discontinued (see OVERDOSAGE ). Thrombocytopenia Thrombocytopenia has been reported to occur in patients receiving heparin with a reported incidence up to 30%. Platelet counts should be obtained at baseline and periodically during heparin administration. Mild thrombocytopenia (count greater than 100,000/mm 3 ) may remain stable or reverse even if heparin is continued. However, thrombocytopenia of any degree should be monitored closely. If the count falls below 100,000/mm 3 or if recurrent thrombosis develops (see Heparin-induced Thrombocytopenia (HIT) (With or Without Thrombosis )), the heparin product should be discontinued and, if necessary, an alternative anticoagulant administered. Heparin-induced Thrombocytopenia (HIT) (With or Without Thrombosis) HIT is a serious immune-mediated reaction resulting from irreversible aggregation of platelets. HIT may progress to the development of venous and arterial thromboses, a condition referred to as HIT with thrombosis. Thrombotic events may also be the initial presentation for HIT. These serious thromboembolic events include deep vein thrombosis, pulmonary embolism, cerebral vein thrombosis, limb ischemia, stroke, myocardial infarction, mesenteric thrombosis, renal arterial thrombosis, skin necrosis, gangrene of the extremities that may lead to amputation, and fatal outcomes. Once HIT (with or without thrombosis) is diagnosed or strongly suspected, all heparin sodium sources (including heparin flushes) should be discontinued and an alternative anticoagulant used. Future use of heparin sodium, especially within 3 to 6 months following the diagnosis of HIT (with or without thrombosis), and while patients test positive for HIT antibodies, should be avoided. Immune-mediated HIT is diagnosed based on clinical findings supplemented by laboratory tests confirming the presence of antibodies to heparin sodium, or platelet activation induced by heparin sodium. A drop in platelet count greater than 50% from baseline is considered indicative of HIT. Platelet counts begin to fall 5 to 10 days after exposure to heparin sodium in heparin sodium-naïve individuals, and reach a threshold by days 7 to 14. In contrast, “rapid onset” HIT can occur very quickly (within 24 hours following heparin sodium initiation), especially in patients with a recent exposure to heparin sodium (i.e. previous 3 months). Thrombosis development shortly after documenting thrombocytopenia is a characteristic finding in almost half of all patients with HIT. Thrombocytopenia of any degree should be monitored closely. If the platelet count falls below 100,000/mm 3 or if recurrent thrombosis develops, the heparin product should be promptly discontinued and alternative anticoagulants considered if patients require continued anticoagulation. Delayed Onset of HIT (With or Without Thrombosis) Heparin-induced Thrombocytopenia (with or without thrombosis) 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 (with or without thrombosis). Use in Neonates Carefully examine all Heparin Sodium Injection vials and syringes to confirm choice of the correct strength prior to administration of the drug. Pediatric patients, including neonates, have died as a result of medication errors in which Heparin Sodium Injection vials have been confused with “catheter lock flush” vials. (See WARNINGS, Fatal Medication Errors .)