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Unfractionated heparin
From WikEM
(Redirected from Heparin (Unfractionated))
Contents
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
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: C
- Lactation risk: Infant risk minimal
- Renal Dosing
- No adjustment
- Hepatic Dosing
- No adjustment
Contraindications
- Allergy to class/drug
- 33% of patients 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
- Recent surgery or trauma
- Renal failure
- Alcoholism
- Malignancy
- Liver failure
- 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 with PTT; therapeutic range is 1.5-2.5x normal value
