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Heparin (Heparin Sodium) - Indications and Dosage

 
 



INDICATIONS AND USAGE

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 DOSAGE AND ADMINISTRATION );

Prophylaxis and treatment of pulmonary embolism;

Atrial fibrillation with embolization;

Diagnosis and 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 and in blood samples for laboratory purposes .

DOSAGE AND ADMINISTRATION

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. 

Confirm the choice of the correct Heparin Sodium Injection vial prior to administration of the drug to a patient (see WARNINGS , Fatal Medication Errors ). The 1 mL vial must not be confused with a ‘‘catheter lock flush’’ vial or other 1 mL vial of inappropriate strength.  Confirm that you have selected the correct medication and strength prior to administration of the drug.

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 intramuscular route of administration should be avoided because of the frequent occurrence of hematoma at the injection site.

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.

Converting to Oral Anticoagulant

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.

Therapeutic Anticoagulant Effect with Full-Dose Heparin

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

 

or

 Every

12 hours

8,000 to 10,000 units of a concentrated solution

 

 

 

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


Pediatric Use

Follow recommendations of appropriate pediatric reference texts.  In general, the following dosage schedule may be used as a guideline:

Initial Dose: 50 units/kg (IV, infusion)

Maintenance Dose: 100 units/kg (IV, infusion) every four hours, or 20,000 units/m2/24 hours continuously

Geriatric Use

Patients over 60 years of age may require lower doses of heparin.

Surgery of the Heart and Blood Vessels

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.

Low-Dose Prophylaxis of Postoperative Thromboembolism

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 WARNINGS ).  The value of such prophylaxis in hip surgery has not been established.  The possibility of increased bleeding during surgery or postoperatively should be borne in mind.  If such bleeding occurs, discontinuance of heparin and neutralization with protamine sulfate are advisable.  If clinical evidence of thromboembolism develops despite low-dose prophylaxis, full therapeutic doses of anticoagulants should be given unless contraindicated.  All patients should be screened prior to heparinization to rule out bleeding disorders, and monitoring should be performed with appropriate coagulation tests just prior to surgery.  Coagulation test values should be normal or only slightly elevated.  There is usually no need for daily monitoring of the effect of low-dose heparin in patients with normal coagulation parameters.

Extracorporeal Dialysis

Follow equipment manufacturers’ operating directions carefully.

Blood Transfusion

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.

Laboratory Samples

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.

STORAGE

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

HOW SUPPLIED

Heparin Sodium Injection, USP (porcine), contains parabens and is available in multiple dose, flip-top vials, in packages of 25, as follows:

Product

No.

NDC

No.

 Strength

  Fill Volume                       

NP504011

63323-540-57

10,000 USP Heparin

units per 10 mL

(1,000 USP units per mL)

10 mL fill

in a 10 mL vial.

NP926201*

63323-262-55

5,000 USP Heparin

units per 1 mL

1 mL fill in

a 3 mL vial.

*Packaged in a plastic vial.

Use only if solution is clear and seal intact.

Do not use if solution is discolored or contains a precipitate.

This container closure is not made from natural rubber latex.

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