Heparin sodium is indicated for atrial fibrillation associated with embolization:

• Management of acute and chronic consumption coagulopathies (disseminated intravascular coagulation);
• Prevention of clot formation during arterial and cardiac surgery;
• Use as an anticoagulant for prophylaxis and treatment of venous thrombosis and its progression;
• (At low doses) prevention of postoperative deep vein thrombosis and pulmonary embolism in patients undergoing major abdomino-thoracic surgery or those at risk of thromboembolic disorders;
• Prevention and treatment of pulmonary embolism;
• Prevention and treatment of peripheral arterial embolism.

Heparin suppresses reactions that result in blood clotting and the formation of fibrin clots, both in vitro and in vivo. It acts at several points within the normal coagulation cascade. In smaller quantities, heparin, together with antithrombin III (heparin cofactor), helps prevent thrombosis by inactivating activated Factor X and reducing the conversion of prothrombin to thrombin. Once thrombosis has occurred, larger doses of heparin can further inhibit coagulation by neutralizing thrombin and blocking the transformation of fibrinogen into fibrin. Heparin also interferes with the development of a stable fibrin clot by inhibiting the activation of the fibrin-stabilizing factor.

Bleeding time is generally not significantly altered by heparin. Clotting time is extended with full therapeutic doses, whereas low doses usually have minimal or no measurable effect.

Intravenous—

Prevention of re-occlusion of the coronary arteries after thrombolytic therapy in myocardial infarction.

• Adult: 60 U/kg (maximum: 4,000 U) or a bolus dose of 5,000 U if streptokinase has been used, followed by 12 U/kg/hour (maximum: 1,000 U/hour) for a treatment duration of 48 hours.

Intravenous—

Peripheral arterial embolism, unstable angina, venous thromboembolism.

• Adult: 75–80 U/kg or 5,000 U (10,000 U in severe pulmonary embolism) as an IV loading dose, followed by 18 U/kg or 1,000–2,000 U/hour by continuous infusion. Alternatively, intermittent injections of 5,000–10,000 U every 4–6 hours may be used.
• Child: 50 U/kg loading dose, followed by a continuous infusion of 15–25 U/kg/hour.
• Elderly: Reduced doses may be necessary.

Subcutaneous—

Prevention of postoperative venous thromboembolism.

• Adult: 5,000 U administered 2 hours before surgery, then every 8–12 hours for 7 days or until the patient becomes ambulatory.

Subcutaneous—

Venous thromboembolism.

• Adult: 15,000–20,000 U every 12 hours or 8,000–10,000 U every 8 hours.
• Child: 250 U/kg daily.
• Elderly: Lower doses may be required.

The anticoagulant effect is increased when used with drugs that influence platelet function or the coagulation pathway (e.g., antiplatelet agents, thrombolytics, salicylates, NSAIDs, vitamin K antagonists, dextrans, activated protein C). The anticoagulant effect may be reduced when used with glyceryl trinitrate infusion. There is also an increased risk of hyperkalemia when used with ACE inhibitors or angiotensin II receptor antagonists.

Current or previous history of heparin-induced thrombocytopenia; generalized or localized bleeding tendency, including uncontrolled severe hypertension, severe hepatic impairment, active peptic ulcer, acute or subacute septic endocarditis, intracranial hemorrhage, or conditions involving recent injury or surgery of the central nervous system, eyes, or ears. It is also contraindicated in women with threatened abortion, during epidural anesthesia in childbirth, and during locoregional anesthesia in elective surgical procedures (when used for treatment rather than prophylaxis).

Hypersensitivity reactions (such as chills, fever, urticaria, asthma, rhinitis); painful, ischemic, and cyanotic limbs; osteoporosis with long-term use; suppression of aldosterone synthesis leading to hyperkalemia; skin necrosis; temporary hair loss (alopecia); priapism; rebound hyperlipidemia; increased serum levels of AST and ALT; prolonged prothrombin time; and local reactions including irritation, redness, mild pain, hematoma, or ulceration at the injection site.

Pregnancy Pregnancy Category C. Animal studies have shown adverse effects on the fetus (including teratogenic or embryocidal effects), and there are no adequate and well-controlled studies in pregnant women, or such studies are not available. This medication should be used during pregnancy only if the potential benefit justifies the possible risk to the fetus.

Nursing Mothers: Due to its high molecular weight, heparin is unlikely to be excreted in human breast milk, and even if present, it is not expected to be absorbed orally by the infant. However, benzyl alcohol present in maternal serum may pass into breast milk and could be absorbed by the infant. Caution is advised when administering Heparin Sodium Injection to nursing mothers.

Use with caution in patients who have an increased risk of bleeding complications, hypertension (HTN), diabetes mellitus (DM), or pre-existing metabolic acidosis. It should not be used for catheter lock flushing. Caution is also required in patients with hepatic or renal impairment, as well as in elderly patients and during pregnancy and lactation.

Pediatric Use: There are no adequate and well-controlled studies on the use of heparin in pediatric patients. Dosing recommendations are based on clinical experience. Heparin Sodium Injection vials should be carefully checked to ensure the correct strength before administration. Medication errors, including confusion with “catheter lock flush” vials, have led to serious outcomes in pediatric patients, including neonates.

Symptoms: Bleeding may occur, including nosebleeds, blood in urine, or black/tarry stools, which can be early signs of hemorrhage.

Management: Protamine sulfate may be administered by slow IV infusion over about 10 minutes to control severe bleeding (1 mg of protamine sulfate neutralizes approximately 100 U of heparin). Maximum dose: 50 mg as a single dose.

Parenteral anticoagulants

Store between 20–25°C. Protect from freezing.