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Drugs reference index «Heparin»



Pronunciation: (HEP-uh-rin)Class: Anticoagulant

Trade Names:Heparin Sodium- Injection 1,000 units/mL- Injection 2,000 units/mL- Injection 2,500 units/mL- Injection 5,000 units/mL- Injection 10,000 units/mL- Injection 20,000 units/mL- Injection 40,000 units/mL

Trade Names:Hep-Lock- Injection 10 units/mL- Injection 100 units/mL

Trade Names:Hep-Lock U/P- Injection 10 units/mL- Injection 100 units/mL

Hepalean (Canada)Hepalean-Lok (Canada)Heparin Leo (Canada)


Inhibits reactions that lead to clotting.



Heparin sodium is not absorbed from GI; must be given IV or subcutaneous. T max is 2 to 4 h (subcutaneous).


Distribution is controlled by the liver; distributed in plasma and is extensively and nonspecifically protein bound.


The liver and the reticuloendothelial system are the sites of biotransformation.


The average t 1/ 2 is 30 to 180 min, and is dose-dependent and non-linear. Up to 50% is excreted in urine as unchanged.


Heparin is not removed.


Onset is immediate (IV) and 20 to 60 min (subcutaneous).

Special Populations

Renal Function Impairment

The t 1/ 2 may be increased.

Hepatic Function Impairment

The t 1/ 2 may be increased.

Infection/malignancy/pulmonary embolism

The t 1/ 2 may be decreased.


The t 1/ 2 may be increased.

Indications and Usage

Prophylaxis and treatment of venous thrombosis and its extensions, pulmonary embolism (PE), peripheral arterial embolism, and atrial fibrillation with embolization; diagnosis and treatment of acute and chronic consumption coagulopathies (DIC); prevention of postoperative deep venous thrombosis (DVT), and PE.

Unlabeled Uses

Prophylaxis of left ventricular thrombi and cerebrovascular accidents post-MI; treatment of myocardial ischemia; prevention of cerebral thrombosis in evolving strokes; adjunctive treatment of coronary occlusion with acute MI.


Severe thrombocytopenia; uncontrolled bleeding (except because of DIC); patients in whom suitable blood coagulation tests cannot be performed.

Dosage and Administration


Subcutaneous 10,000 to 20,000 unit as initial dose followed by 8000 to 20,000 unit every 8 to 12 h. Intermittent IV 10,000 unit as initial dose followed by 5,000 to 10,000 unit every 4 to 6 h. IV infusion 20,000 to 40,000 unit/day.


Intermittent IV 50 unit/kg as initial dose followed by 100 unit/kg every 4 h. IV infusion 50 unit/kg as initial dose followed by 20,000 unit/m 2 /24 h.

Low-dose Prophylaxis

Subcutaneous 5,000 unit 2 h before surgery and every 8 to 12 h thereafter for 7 days or until patient is fully ambulatory, whichever is longer.

Surgery of Heart and Blood VesselsAdults

300 to 400 unit/kg.

Blood Transfusion

Add 400 to 600 unit/100 mL of whole blood.

Clearing Intermittent Infusion Sets

10 to 100 unit/mL.

Laboratory Samples

Add 70 to 150 unit/10 to 20 mL of whole blood.

General Advice

  • Avoid IM administration.
  • Subcutaneous administration should be deep, preferably into fatty layers of abdomen. Use small-gauge needle to minimize tissue trauma. Bunch up tissue without pinching and insert needle at 90% angle to skin. Inject slowly.
  • Do not aspirate to check entry into blood vessel. Apply gentle pressure to puncture site for approximately 1 min; do not massage. Rotate injection sites frequently and keep record.
  • IV administration may be given undiluted over 1 min.
  • For IV infusion, dilute prescribed amount in Sodium Chloride 0.9% for Injection, D5W, or Ringer's Injection solution. Use infusion pump to ensure accuracy.
  • For heparin locks, inject diluted heparin solution of 10 to 100 unit (0.5 to 1 mL).
  • To prevent incompatibility of heparin with medication, flush heparin lock set with Sterile Water for Injection or Sodium Chloride 0.9% for Injection before and after medication is administered.


Store at room temperature. Protect from freezing.

Drug Interactions

Dipyridamole, hydroxychloroquine, NSAIDs, salicylates

May cause increased risk of bleeding.


Heparin is acidic and incompatible with many drugs.

Laboratory Test Interactions

Aminotransferase (AST and ALT)

Drug causes increased concentrations.

Adverse Reactions


Necrosis; transient alopecia; urticaria.


Hemorrhage; thrombocytopenia.


Hypersensitivity (chills, fever, urticaria, asthma, rhinitis, lacrimation, headache, nausea, vomiting, shock); anaphylactoid reactions; allergic vasospastic reactions, including painful ischemia, cyanotic limbs; osteoporosis; priapism; rebound hyperlipidemia on discontinuation.



Category C .


Not excreted in breast milk.


Higher incidence of bleeding in women older than 60 yr of age.


Generalized hypersensitivity can occur. Reactions range from mild to severe.

Benzyl alcohol sensitivity

Benzyl alcohol, used as preservative in some products, is associated with a fatal gasping syndrome in premature infants.

Debilitated patients

Higher incidence of bleeding in women older than 60 yr.


Hemorrhage can occur at virtually any site. Use heparin with extreme caution in patients at increased risk of hemorrhage.


Heparin administration may cause hyperlipidemia in patients with dysbetalipoproteinemia (type III).

IM use

Avoid IM use because of local irritation, erythema, pain, hematoma, or ulceration.



Bleeding, nosebleeds, hematuria, tarry stools, easy bruising, or petechiae.

Patient Information

  • Caution patient to avoid IM injections.
  • Advise patient to avoid activities that carry risk of injury.
  • Instruct patient to use soft toothbrush and electric razor.
  • Caution patient to avoid aspirin and aspirin-containing medications.
  • Advise patient to report unusual bruising or bleeding (eg, nosebleeds, bleeding gums) or tarry stools to health care provider immediately.
  • Instruct patient to inform health care provider and dentist of use of this medication before treatment or surgery.
  • Inform patient of potential for hair loss. Explain that this effect may occur several months after heparin therapy is started. Reassure patient that if alopecia occurs, hair growth will return after drug has been discontinued.
  • Advise patient to carry identification card or to wear a medication identification bracelet (ie, Medi-Alert ) that indicates heparin therapy.
  • Inform women that menstruation may be somewhat increased and prolonged. Usually this effect is not a contraindication to therapy if bleeding is not excessive and there is no underlying pathologic condition.
  • Advise patient that smoking and alcohol may alter response to heparin, and therefore, are not advised.
  • Inform patient that abrupt withdrawal of heparin may precipitate increased coagulability.

Copyright © 2009 Wolters Kluwer Health.

  • Heparin MedFacts Consumer Leaflet (Wolters Kluwer)
  • Heparin Prescribing Information (FDA)
  • heparin Intravenous, Subcutaneous Advanced Consumer (Micromedex) - Includes Dosage Information
  • heparin Concise Consumer Information (Cerner Multum)

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