Unfractionated heparin

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General

  • Type: Anticoagulant
  • Dosage Forms: IV, SC
  • Common Trade Names: Heparin

Adult Dosing

Thromboembolism

  • Bolus: 80 units/kg IV x 1 (MAX: 5,000 units)
  • Then drip: 18 units/kg/h IV (MAX: 1,000 units/h)
  • Adjust dose to target aPTT levels based on nomogram

Acute Coronary Syndrome

  • Bolus: 50 units/kg IV x 1 (MAX: 5,000 units)
  • Then drip: 12 units/kg/h IV (MAX: 1,000 units/h)
  • Adjust dose to target aPTT levels based on nomogram

Pediatric Dosing

  • IV infusion
    • Initial loading dose 75 units/kg given over 10 minutes
    • Initial maintenance dose 20 units/kg/hour and adjest per local policy

Special Populations

Contraindications

Risk Factors for Major Bleeding Complication

  • Recent surgery or trauma
  • Renal failure
  • Alcoholism
  • Malignancy
  • Liver failure
  • Concurrent use of warfarin, fibrinolytics, steroids, or antiplatelet drugs

Adverse Reactions

Serious

  • Major bleeding
  • Thrombocytopenia

Common

  • Injection site reaction[1]
  • Hyperkalemia
  • Alopecia
  • Osteoporosis

Pharmacology

  • Half-life: 1.5 hrs
  • Metabolism: Hepatic
  • Excretion: Urine
  • Mechanism of Action:
    • Binds to and activates antithrombin which in turns inactivates factor Xa and thrombin
  • Anticoagulation effect lasts up to 3hr after stopping infusion
  • Must give IV (not subq) for acute thromboembolic disease
    • Unpredictable anticoagulation effect
    • Must monitor with PTT; therapeutic range is 1.5-2.5x normal value

See Also

References

  1. Warnock LB, Huang D. Heparin. [Updated 2022 Jul 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538247/