Heparin Sodium
Heparin Sodium Prescribing Information
Heparin Sodium Injection is indicated for:
Anticoagulant therapy in prophylaxis and treatment of venous thrombosis and its extension;
Low-dose regimen for prevention of postoperative deep venous thrombosis and pulmonary embolism in patients undergoing major abdominothoracic surgery or who, for other reasons, are at risk of developing thromboembolic disease (see
When heparin is added to an infusion solution for continuous intravenous administration, the container should be inverted at least six times to ensure adequate mixing and prevent pooling of the heparin in the solution.
Heparin sodium is not effective by oral administration and should be given by intermittent intravenous injection, intravenous infusion, or deep subcutaneous (intrafat, i.e., above the iliac crest or abdominal fat layer) injection.
The dosage of heparin sodium should be adjusted according to the patient’s coagulation test results. When heparin is given by continuous intravenous infusion, the coagulation time should be determined approximately every four hours in the early stages of treatment. When the drug is administered intermittently by intravenous injection, coagulation tests should be performed before each injection during the early stages of treatment and at appropriate intervals thereafter. 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. After deep subcutaneous (intrafat) injections, tests for adequacy of dosage are best performed on samples drawn four to six hours after the injection.
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.
When an oral anticoagulant of the coumarin or similar type is to be begun in patients already receiving heparin sodium, baseline and subsequent tests of prothrombin activity must be determined at a time when heparin activity is too low to affect the prothrombin time. This is about five hours after the last IV bolus and 24 hours after the last subcutaneous dose. If continuous IV heparin infusion is used, prothrombin time can usually be measured at any time.
In converting from heparin to an oral anticoagulant, the dose of the oral anticoagulant should be the usual initial amount and thereafter prothrombin time should be determined at the usual intervals. To ensure continuous anticoagulation, it is advisable to continue full heparin therapy for several days after the prothrombin time has reached the therapeutic range. Heparin therapy may then be discontinued without tapering.
Although dosage must be adjusted for the individual patient according to the results of suitable laboratory tests, the following dosage schedules may be used as guidelines:
METHOD OF ADMINISTRATION | FREQUENCY | RECOMMENDED DOSE (based on 150 lb [68 kg] patient) |
Deep Subcutaneous (Intrafat) Injection A different site should be used for each injection to prevent the development of massive hematoma | Initial Dose | 5,000 units by IV injection, followed by 10,000 to 20,000 units of a concentrated solution, subcutaneously |
Every 8 hours | 8,000 to 10,000 units of a concentrated solution | |
or Every 12 hours | 15,000 to 20,000 units of a concentrated solution | |
Intermittent Intravenous Injection | Initial Dose | 10,000 units, either undiluted or in 50 to 100 mL of 0.9% Sodium Chloride Injection, USP |
Every 4 to 6 hours | 5,000 to 10,000 units, either undiluted or in 50 to 100 mL of 0.9% Sodium Chloride Injection, USP | |
Intravenous Infusion | Initial Dose | 5,000 units by IV injection |
Continuous | 20,000 to 40,000 units/24 hours in 1,000 mL of 0.9% Sodium Chloride Injection, USP (or in any compatible solution) for infusion |
Use preservative-free HEPARIN SODIUM INJECTION in neonates and infants (see
There are no adequate and well-controlled studies on heparin use in pediatric patients. Pediatric dosing recommendations are based on clinical experience. In general, the following dosage schedule may be used as a guideline in pediatric patients:
Initial Dose 75 to 100 units/kg (IV bolus over 10 minutes)
Maintenance Dose Infants: 25 to 30 units/kg/hour;
Infants < 2 months have the highest requirements
(average 28 units/kg/hour)
Children > 1 year of age: 18 to 20 units/kg/hour;
Older children may require less heparin, similar to weight-adjusted
adult dosage
Monitoring Adjust heparin to maintain aPTT of 60 to 85 seconds, assuming this
reflects an anti-Factor Xa level of 0.35 to 0.70.
Patients over 60 years of age may require lower doses of heparin.
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 of heparin sodium per kilogram of body weight 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.
A number of well-controlled clinical trials have demonstrated that low-dose heparin prophylaxis, given just prior to and after surgery, will reduce the incidence of postoperative deep vein thrombosis in the legs (as measured by the I-125 fibrinogen technique and venography) and of clinical pulmonary embolism. 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 seven days or until the patient is fully ambulatory, whichever is longer. The heparin is given by deep subcutaneous injection in the arm or abdomen with a fine needle (25 to 26 gauge) to minimize tissue trauma. A concentrated solution of heparin sodium is recommended. Such prophylaxis should be reserved for patients over the age of 40 who are undergoing major surgery. Patients with bleeding disorders and those having neurosurgery, spinal anesthesia, eye surgery or potentially sanguineous operations should be excluded, as well as patients receiving oral anticoagulants or platelet-active drugs (see
Follow equipment manufacturers’ operating directions carefully.
Addition of 400 to 600 USP units per 100 mL of whole blood is usually employed 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/1,000 mL of 0.9% Sodium Chloride Injection, USP) and mixed; from this sterile solution, 6 to 8 mL are added per 100 mL of whole blood.
Addition of 70 to 150 units of heparin sodium per 10 to 20 mL sample of whole blood is usually employed to prevent coagulation of the sample. Leukocyte counts should be performed on heparinized blood within two hours after addition of the heparin. Heparinized blood should not be used for isoagglutinin, complement, or erythrocyte fragility tests or platelet counts.
Prophylaxis and treatment of pulmonary embolism;
Atrial fibrillation with embolization;
Treatment of acute and chronic consumptive coagulopathies (disseminated intravascular coagulation);
Prevention of clotting in arterial and cardiac surgery;
Prophylaxis and treatment of peripheral arterial embolism.
Heparin may also be employed as an anticoagulant in blood transfusions, extracorporeal circulation, and dialysis procedures.
Addition of 70 to 150 units of heparin sodium per 10 to 20 mL sample of whole blood is usually employed to prevent coagulation of the sample. Leukocyte counts should be performed on heparinized blood within two hours after addition of the heparin. Heparinized blood should not be used for isoagglutinin, complement, or erythrocyte fragility tests or platelet counts.
Heparin sodium should NOT be used in patients with the following conditions:
Severe thrombocytopenia;
When suitable blood coagulation tests, e.g., the whole blood clotting time, partial thromboplastin time, etc., cannot be performed at appropriate intervals (this contraindication refers to full-dose heparin; there is usually no need to monitor coagulation parameters in patients receiving low-dose heparin);
An uncontrollable active bleeding state (see
Heparin is not intended for intramuscular use.
Do not use Heparin Sodium Injection as a “catheter lock flush” product. Heparin Sodium Injection is supplied in vials containing various strengths of heparin, including vials that contain a highly concentrated solution of 10,000 units in 1 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 to confirm the correct vial choice prior to administration of the drug.
Use preservative-free HEPARIN SODIUM INJECTION in neonates and infants. The preservative benzyl alcohol has been associated with serious adverse events and death in pediatric patients. The minimum amount of benzyl alcohol at which toxicity may occur is not known. Premature and low-birth weight infants may be more likely to develop toxicity (see
Patients with documented hypersensitivity to heparin should be given the drug only in clearly life-threatening situations (see
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:
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
Thrombocytopenia has been reported to occur in patients receiving heparin with a reported incidence of up to 30%. Platelet counts should be obtained at baseline and periodically during heparin administration. Mild thrombocytopenia (count greater than 100,000/mm3) 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/mm3or if recurrent thrombosis develops (see
Heparin-induced Thrombocytopenia and Heparin-induced Thrombocytopenia and Thrombosis 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 and HITT.
Osteoporosis following long-term administration of high doses of heparin, 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.
Significant elevations of aminotransferase (SGOT [S-AST] and SGPT [S-ALT]) levels have occurred in a high percentage of patients (and healthy subjects) who have received heparin.
Heparin is a heterogeneous group of straight-chain anionic mucopolysaccharides, called glycosaminoglycans, having anticoagulant properties. Although others may be present, the main sugars occurring in heparin are: (1) α-L-iduronic acid 2-sulfate, (2) 2-deoxy-2-sulfamino-α-D-glucose 6-sulfate, (3) ß-D-glucuronic acid, (4) 2-acetamido-2-deoxy-α-D-glucose and (5) α-L-iduronic acid. These sugars are present in decreasing amounts, usually in the order (2)> (1)> (4)> (3)> (5), and are joined by glycosidic linkages, forming polymers of varying sizes. Heparin is strongly acidic because of its content of covalently linked sulfate and carboxylic acid groups. In heparin sodium, the acidic protons of the sulfate units are partially replaced by sodium ions.
Heparin Sodium Injection, USP is a sterile solution of heparin sodium derived from porcine intestinal mucosa, standardized for anticoagulant activity, in water for injection. It is to be administered by intravenous or deep subcutaneous routes. The potency is determined by a biological assay using a USP reference standard based on units of heparin activity per milligram.
Structure of Heparin Sodium (representative subunits):
Each mL of the 1,000 units per mL preparation contains: 1,000 USP Heparin units (porcine); 9 mg sodium chloride; Water for Injection q.s. Made isotonic with sodium chloride. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each 0.5 mL of the 5,000 units per 0.5 mL preparation contains: 5,000 USP Heparin units (porcine); Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 5,000 units per mL preparation contains: 5,000 USP Heparin units (porcine); 6 mg sodium chloride; 15 mg benzyl alcohol (as a preservative); Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 10,000 units per mL preparation contains: 10,000 USP Heparin units (porcine); 5 mg sodium chloride; 10.42 mg benzyl alcohol (as a preservative); Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 1,000 units per mL preparation contains: 1,000 USP Heparin units (porcine); 9 mg sodium chloride; 1.5 mg methylparaben; 0.15 mg propylparaben; Water for Injection q.s. Made isotonic with sodium chloride. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 5,000 units per mL preparation contains: 5,000 USP Heparin units (porcine); 5 mg sodium chloride; 1.5 mg methylparaben; 0.15 mg propylparaben; Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 10,000 units per mL preparation contains: 10,000 USP Heparin units (porcine); 1.5 mg methylparaben; 0.15 mg propylparaben; Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Each mL of the 20,000 units per mL preparation contains: 20,000 USP Heparin units (porcine); 1.5 mg methylparaben; 0.15 mg propylparaben; Water for Injection q.s. Hydrochloric acid and/or sodium hydroxide may have been added for pH adjustment (5.0 to 7.5).
Heparin inhibits reactions that lead to the clotting of blood and the formation of fibrin clots both
Bleeding time is usually unaffected by heparin. Clotting time is prolonged by full therapeutic doses of heparin; in most cases, it is not measurably affected by low doses of heparin.
Patients over 60 years of age, following similar doses of heparin, may have higher plasma levels of heparin and longer activated partial thromboplastin times (APTTs) compared with patients under 60 years of age.
Peak plasma levels of heparin are achieved two to four hours following subcutaneous administration, although there are considerable individual variations. Loglinear plots of heparin plasma concentrations with time, for a wide range of dose levels, are linear, which suggests the absence of zero order processes. Liver and the reticuloendothelial system are the sites of biotransformation. The biphasic elimination curve, a rapidly declining alpha phase (t
1⁄2 = 10 minutes) and after the age of 40 a slower beta phase, indicates uptake in organs. The absence of a relationship between anticoagulant half-life and concentration half-life may reflect factors such as protein binding of heparin.
Heparin does not have fibrinolytic activity; therefore, it will not lyse existing clots.