2.1 Preparation for Administration

Confirm the choice of the correct heparin sodium injection syringe to ensure that the 1 mL syringe is not confused with a “catheter lock flush” syringe or other 1 mL syringe of incorrect strength [see Warnings and Precautions (5.1)]. Confirm the selection of the correct formulation and strength prior to administration of the drug.

When heparin sodium is added to an infusion solution for continuous intravenous administration, invert the container repeatedly to ensure adequate mixing and prevent pooling of the heparin sodium in the solution. Visually inspect parenteral drug products for particulate matter and discoloration prior to administration, whenever solution and container permit. Use only if solution is clear and the seal is intact. Do not use if solution is discolored or contains a precipitate.

Administer heparin sodium injection by intermittent intravenous injection, intravenous infusion, or deep subcutaneous (intrafat, i.e., above the iliac crest or abdominal fat layer) injection. Do not administer heparin sodium injection by intramuscular injection because of the risk of hematoma at the injection site [see Adverse Reactions (6)].

2.2 Laboratory Monitoring for Efficacy and Safety

Adjust the dosage of heparin sodium injection according to the patient's coagulation test results. Dosage is considered adequate when the activated partial thromboplastin time (aPTT) is 1.5 to 2 times normal or when the whole blood clotting time is elevated approximately 2.5 to 3 times the control value. When initiating treatment with heparin sodium injection by continuous intravenous infusion, determine the coagulation status (aPTT, INR, platelet count) at baseline and continue to follow aPTT approximately every 4 hours and then at appropriate intervals thereafter. When the drug is administered intermittently by intravenous injection, perform coagulation tests before each injection during the initiation of treatment and at appropriate intervals thereafter. After deep subcutaneous (intrafat) injections, tests for adequacy of dosage are best performed on samples drawn 4 to 6 hours after the injection.

Periodically monitor platelet counts and hematocrits during the entire course of heparin sodium therapy, regardless of the route of administration.

2.3 Therapeutic Anticoagulant Effect with Full-Dose Heparin Sodium

The dosing recommendations in Table 1 are based on clinical experience. Although dosages must be adjusted for the individual patient according to the results of suitable laboratory tests, the following dosage schedules may be used as guidelines:

2.4 Cardiovascular Surgery

Patients undergoing total body perfusion for open-heart surgery should receive an initial dose of not less than 150 units of heparin sodium per kilogram of body weight. Frequently, a dose of 300 units per kilogram is used for procedures estimated to last less than 60 minutes, or 400 units per kilogram for those estimated to last longer than 60 minutes.

2.5 Low-Dose Prophylaxis of Postoperative Thromboembolism

The most widely used dosage has been 5,000 units 2 hours before surgery and 5,000 units every 8 to 12 hours thereafter for 7 days or until the patient is fully ambulatory, whichever is longer. Administer the heparin sodium by deep subcutaneous (intrafat, i.e., above the iliac crest or abdominal fat layer, arm, or thigh) injection with a fine (25- to 27-gauge) needle to minimize tissue trauma.

2.6 Blood Transfusion

Add 450 USP units to 600 USP units of heparin sodium per 100 mL of whole blood to prevent coagulation. Usually, 7,500 USP units of heparin sodium are added to 100 mL of 0.9% Sodium Chloride Injection, USP (or 75,000 USP units per 1,000 mL of 0.9% Sodium Chloride Injection, USP) and mixed; from this sterile solution, 6 mL to 8 mL are added per 100 mL of whole blood.

2.7 Converting to Warfarin

To ensure continuous anticoagulation when converting from heparin sodium injection to warfarin, continue full heparin sodium therapy for several days until the INR (prothrombin time) has reached a stable therapeutic range. Heparin sodium therapy may then be discontinued without tapering [see Drug Interactions (7.1)].

2.8 Converting to Oral Anticoagulants other than Warfarin

For patients currently receiving intravenous heparin sodium, stop intravenous infusion of heparin sodium immediately after administering the first dose of oral anticoagulant; or for intermittent intravenous administration of heparin sodium, start oral anticoagulant 0 to 2 hours before the time that the next dose of heparin sodium injection was to have been administered.

2.9 Extracorporeal Dialysis

Follow equipment manufacturers' operating directions carefully. A dose of 25 units/kg to 30 units/kg followed by an infusion rate of 1,500 units/hour to 2,000 units/hour is suggested based on pharmacodynamic data if specific manufacturers' recommendations are not available.

2.10 Administration Technique

Figure 1: Outer Packaging and Prefilled Syringe

NOTES:

-Do not introduce any other fluid into the syringe at any time.

-Do not dilute for intravenous push.

-Do not re-sterilize the syringe.

-Do not use this product on a sterile field.

-This product is for single dose only.

1. Inspect the outer packaging (blister pack) to confirm the integrity of the packaging. Do not use if the blister pack or the prefilled syringe has been damaged.
2. Remove the syringe from the outer packaging. (See Figure 2)

   Figure 2

   

3. Visually inspect the syringe. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
4. Twist off the syringe tip cap. (See Figure 3)

   Figure 3

   

5. Expel air bubble(s). Adjust the dose (if applicable).
6. Administer the dose ensuring that pressure is maintained on the plunger rod during the entire administration.
7. Discard the syringe into the appropriate receptacle.

5.1 Fatal Medication Errors

Do not use heparin sodium injection as a “catheter lock flush” product. Heparin sodium injection is supplied in syringes containing a highly concentrated solution of 10,000 units in 1 mL (5,000 units per 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 syringes to confirm the correct syringe choice prior to administration of the drug.

5.2 Hemorrhage

Avoid using heparin sodium in the presence of major bleeding, except when the benefits of heparin sodium therapy outweigh the potential risks.

Hemorrhage can occur at virtually any site in patients receiving heparin sodium. Fatal hemorrhages have occurred. Adrenal hemorrhage (with resultant acute adrenal insufficiency), ovarian hemorrhage, and retroperitoneal hemorrhage have occurred during anticoagulant therapy with heparin sodium [see Adverse Reactions (6.1)]. A higher incidence of bleeding has been reported in patients, particularly women, over 60 years of age [see Clinical Pharmacology (12.3)]. An unexplained fall in hematocrit, 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:

• 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.
• Patients with hereditary antithrombin III deficiency receiving concurrent antithrombin III therapy
  - The anticoagulant effect of heparin sodium 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 sodium dose during concomitant treatment with antithrombin III (human).
• Gastrointestinal - Ulcerative lesions and continuous tube drainage of the stomach or small intestine.
• Other - Menstruation, liver disease with impaired hemostasis.

5.3 Heparin Sodium-Induced Thrombocytopenia and Heparin Sodium-Induced Thrombocytopenia and Thrombosis

Heparin sodium-induced thrombocytopenia (HIT) is a serious antibody-mediated reaction. HIT occurs in patients treated with heparin sodium and is due to the development of antibodies to a platelet Factor 4-heparin complex that induce in vivo platelet aggregation. HIT may progress to the development of venous and arterial thromboses, a condition referred to as heparin sodium-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, 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 sodium, 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 sodium therapy. Patients presenting with thrombocytopenia or thrombosis after discontinuation of heparin sodium should be evaluated for HIT or HITT.

5.4 Thrombocytopenia

Thrombocytopenia in patients receiving heparin sodium has been reported at frequencies up to 30%. It can occur 2 to 20 days (average 5 to 9) following the onset of heparin sodium therapy. Obtain platelet counts before and periodically during heparin sodium therapy. Monitor thrombocytopenia of any degree closely. If the count falls below 100,000/mm3 or if recurrent thrombosis develops, promptly discontinue heparin sodium, evaluate for HIT and HITT, and, if necessary, administer an alternative anticoagulant [see Warnings and Precautions (5.3)].

5.5 Coagulation Testing and Monitoring

When using a full dose heparin sodium regimen, adjust the heparin sodium dose based on frequent blood coagulation tests. If the coagulation test is unduly prolonged or if hemorrhage occurs, discontinue heparin sodium promptly [see Overdosage (10)]. Periodic platelet counts and hematocrits are recommended during the entire course of heparin sodium therapy, regardless of the route of administration [see Dosage and Administration (2.2)].

5.6 Heparin Sodium Resistance

Resistance to heparin sodium is frequently encountered in fever, thrombosis, thrombophlebitis, infections with thrombosing tendencies, myocardial infarction, cancer, in postsurgical patients, and patients with antithrombin III deficiency. Close monitoring of coagulation tests is recommended in these cases. Adjustment of heparin sodium doses based on anti-Factor Xa levels may be warranted.

5.7 Hypersensitivity

Patients with documented hypersensitivity to heparin sodium should be given the drug only in clearly life- threatening situations.

Because heparin sodium is derived from animal tissue, it should be used with caution in patients with a history of allergy.

5.8 Hyperkalemia

Heparin can suppress adrenal secretion of aldosterone leading to hyperkalemia, particularly in patients with diabetes mellitus, chronic renal failure, pre-existing metabolic acidosis, a raised plasma potassium, or taking potassium sparing drugs. The risk of hyperkalemia appears to increase with duration of therapy but is usually reversible upon discontinuation of heparin.

Measure blood potassium in patients at risk of hyperkalemia before starting heparin therapy and periodically in all patients treated for more than 5 days or earlier as deemed fit by the clinician.

6.1 Postmarketing Experience

The following adverse reactions have been identified during post approval use of heparin sodium injection. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

• Hemorrhage is the chief complication that may result from heparin sodium therapy [see Warnings and Precautions (5.2)]. Gastrointestinal or urinary tract bleeding during anticoagulant therapy may indicate the presence of an underlying occult lesion. Bleeding can occur at any site but certain specific hemorrhagic complications may be difficult to detect:
  • Adrenal hemorrhage, with resultant acute adrenal insufficiency, has occurred with heparin sodium therapy, including fatal cases.
  • Ovarian (corpus luteum) hemorrhage developed in a number of women of reproductive age receiving short- or long-term heparin sodium therapy.
  • Retroperitoneal hemorrhage
• HIT and HITT, including delayed onset cases [see Warnings and Precautions (5.3)].
• Local Irritation – Local irritation, erythema, mild pain, hematoma or ulceration may follow deep subcutaneous (intrafat) injection of heparin sodium. Because these complications are much more common after intramuscular use, the intramuscular route is not recommended.
• Histamine-like reactions – Such reactions have been observed at the site of injections. Necrosis of the skin has been reported at the site of subcutaneous injection of heparin sodium, occasionally requiring skin grafting [see Warnings and Precautions (5.3)].
• Hypersensitivity – Generalized hypersensitivity reactions have been reported, with chills, fever and urticaria as the most usual manifestations, and asthma, rhinitis, lacrimation, headache, nausea and vomiting, and anaphylactoid reactions, including shock, occurring less frequently. Itching and burning, especially on the plantar side of the feet, may occur [see Warnings and Precautions (5.7)].
• Elevations of aminotransferases – Significant elevations of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels have occurred in patients who have received heparin sodium.
• Miscellaneous - Osteoporosis following long-term administration of high doses of heparin sodium, cutaneous necrosis after systemic administration, suppression of aldosterone synthesis, delayed transient alopecia, priapism, and rebound hyperlipemia on discontinuation of heparin sodium have also been reported.
• Metabolism and Nutrition Disorders – Hyperkalemia.

7.1 Oral Anticoagulants

Heparin sodium may prolong the one-stage prothrombin time. Therefore, when heparin sodium is given with dicumarol or warfarin sodium, a period of at least 5 hours after the last intravenous dose or 24 hours after the last subcutaneous dose should elapse before blood is drawn, if a valid prothrombin time is to be obtained.

7.2 Platelet Inhibitors

Drugs such as NSAIDS (including salicylic acid, ibuprofen, indomethacin, and celecoxib), dextran, phenylbutazone, thienopyridines, dipyridamole, hydroxychloroquine, glycoprotein IIb/IIIa antagonists (including abciximab, eptifibatide, and tirofiban), and others that interfere with platelet-aggregation reactions (the main hemostatic defense of heparinized patients) may induce bleeding and should be used with caution in patients receiving heparin sodium. To reduce the risk of bleeding, a reduction in the dose of antiplatelet agent or heparin sodium is recommended.

7.3 Other Interactions

Digitalis, tetracyclines, nicotine or antihistamines may partially counteract the anticoagulant action of heparin sodium. Intravenous nitroglycerin administered to heparinized patients may result in a decrease of the partial thromboplastin time with subsequent rebound effect upon discontinuation of nitroglycerin. Careful monitoring of partial thromboplastin time and adjustment of heparin sodium dosage are recommended during coadministration of heparin sodium and intravenous nitroglycerin.

Antithrombin III (human) – The anticoagulant effect of heparin sodium is enhanced by concurrent treatment with antithrombin III (human) in patients with hereditary antithrombin III deficiency. To reduce the risk of bleeding, a reduced dosage of heparin sodium is recommended during treatment with antithrombin III (human).

8.1 Pregnancy

8.2 Lactation

8.4 Pediatric Use

Pediatric dosing is not achievable with the prefilled syringe presentation. Use another heparin sodium product presentation when dosing pediatric patients.

8.5 Geriatric Use

There are limited adequate and well-controlled studies in patients 65 years and older, however, a higher incidence of bleeding has been reported in patients, particularly women, over 60 years of age [see Warnings and Precautions (5.2)]. Patients over 60 years of age may require lower doses of heparin sodium. Lower doses of heparin sodium may be indicated in these patients [see Clinical Pharmacology (12.3)].

Neutralization of Heparin Sodium Effect

When clinical circumstances (bleeding) require reversal of the heparin sodium effect, protamine sulfate (1% solution) by slow infusion will neutralize heparin sodium. No more than 50 mg should be administered, very slowly, in any 10-minute period. Each mg of protamine sulfate neutralizes approximately 100 USP heparin sodium units. The amount of protamine required decreases over time as heparin sodium is metabolized. Although the metabolism of heparin sodium is complex, it may, for the purpose of choosing a protamine dose, be assumed to have a half-life of about 1/2 hour after intravenous injection.

Because fatal reactions often resembling anaphylaxis have been reported with protamine, it should be given only when resuscitation techniques and treatment of anaphylactoid shock are readily available.

For additional information consult the labeling of protamine sulfate injection.

12.1 Mechanism of Action

Heparin sodium interacts with the naturally occurring plasma protein, Antithrombin III, to induce a conformational change, which markedly enhances the serine protease activity of Antithrombin III, thereby inhibiting the activated coagulation factors involved in the clotting sequence, particularly Xa and IIa. Small amounts of heparin sodium inhibit Factor Xa, and larger amounts inhibit thrombin (Factor IIa). Heparin sodium also prevents the formation of a stable fibrin clot by inhibiting the activation of the fibrin stabilizing factor. Heparin sodium does not have fibrinolytic activity; therefore, it will not lyse existing clots.

12.2 Pharmacodynamics

Various times (activated clotting time, activated partial thromboplastin time, prothrombin time, whole blood clotting time) are prolonged by full therapeutic doses of heparin sodium; in most cases, they are not measurably affected by low doses of heparin sodium. The bleeding time is usually unaffected by heparin sodium.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

No long-term studies in animals have been performed to evaluate carcinogenic potential of heparin sodium. Also, no reproduction studies in animals have been performed concerning mutagenesis or impairment of fertility.

Storage Conditions

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.]

Discard unused portion.
Protect from freezing.
Do not place syringe on a sterile field.

Hemorrhage

Inform patients that it may take them longer than usual to stop bleeding, that they may bruise and/or bleed more easily when they are treated with heparin sodium, and that they should report any unusual bleeding or bruising to their physician. Hemorrhage can occur at virtually any site in patients receiving heparin sodium. Fatal hemorrhages have occurred [see Warnings and Precautions (5.2)].

Prior to Surgery

Advise patients to inform physicians and dentists that they are receiving heparin sodium before any surgery is scheduled [see Warnings and Precautions (5.2)].

Heparin Sodium-Induced Thrombocytopenia

Inform patients of the risk of heparin sodium-induced thrombocytopenia (HIT). HIT may progress to the development of venous and arterial thromboses, a condition known as heparin sodium-induced thrombocytopenia and thrombosis (HITT). HIT and HITT can occur up to several weeks after the discontinuation of heparin sodium therapy [see Warnings and Precautions (5.3)].

Hypersensitivity

Inform patients that generalized hypersensitivity reactions have been reported. Necrosis of the skin has been reported at the site of subcutaneous injection of heparin sodium [see Warnings and Precautions (5.7), Adverse Reactions (6.1)].

Other Medications

Because of the risk of hemorrhage, advise patients to inform their physicians and dentists of all medications they are taking, including non-prescription medications, and before starting any new medication [see Drug Interactions (7.1)].

For more information concerning this drug, please call Meitheal Pharmaceuticals Inc. at 1-844-824-8426.

To report SUSPECTED ADVERSE REACTIONS, contact Meitheal Pharmaceuticals Inc. at 1-844-824-8426 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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Mfd. for Meitheal Pharmaceuticals
Chicago, IL 60631 (USA)
©2025 Meitheal Pharmaceuticals Inc.

Revised: January 2025

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