Unfractionated heparin

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

PCI

1. See:
   1. DVT
   2. PE
   3. NSTEMI
   4. STEMI

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

• Pregnancy Rating: Safe in pregnancy
• Lactation:
• Renal Dosing
  • No adjustment
• Hepatic Dosing
  • No adjustment

Contraindications

• Allergy to class/drug
• 33% of pts develop some form of bleeding complication; 2-6% develop major bleeding
• Heparin-Induced Thrombocytopenia
• See HIT (Heparin-Induced Thrombocytopenia)

Risk Factors for Major Bleeding Complication

1. Recent surgery or trauma
2. Renal failure
3. Alcoholism
4. Malignancy
5. Liver failure
6. Concurrent use of warfarin, fibrinolytics, steroids, or antiplatelet drugs

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 w/ PTT; therapeutic range is 1.5-2.5x normal value

See Also

• Coagulopathy (Main)
• Low Molecular Weight Heparin
• Heparin reversal