Unfractionated heparin: Difference between revisions

 
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==Background==
==General==
*Binds to and activates antithrombin which in turns inactivates factor Xa and thrombin
*Type: [[Anticoagulant]]
*Anticoagulation effect lasts up to 3hr after stopping infusion
*Dosage Forms: IV, SC
*Must give IV (not subq) for acute thromboembolic disease
*Common Trade Names: Heparin
*Safe in pregnancy
 
*Unpredictable anticoagulation effect
==Adult Dosing==
**Must monitor w/ PTT; therapeutic range is 1.5-2.5x normal value
===Thromboembolism===
*33% of pts develop some form of bleeding complication; 2-6% develop major bleeding
*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==
*[[Drug Ratings in Pregnancy|Pregnancy Rating]]: C
*[[Lactation risk categories|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
*[[HIT (Heparin-Induced Thrombocytopenia)]]


===Risk Factors for Major Bleeding Complication===
===Risk Factors for Major Bleeding Complication===
#Recent surgery or trauma
*Recent surgery or trauma
#Renal failure
*Renal failure
#Alcoholism
*Alcoholism
#Malignancy
*Malignancy
#Liver failure
*Liver failure
#Concurrent use of warfarin, fibrinolytics, steroids, or antiplatelet drugs
*Concurrent use of warfarin, fibrinolytics, steroids, or antiplatelet drugs


==Treatment ==
==Adverse Reactions==
#See:
===Serious===
##[[DVT]]
*Major bleeding
##[[PE]]
*Thrombocytopenia
##[[NSTEMI]]
##[[STEMI]]


==Complications==
===Common===
#Bleeding
*Injection site reaction<ref>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/</ref>
##Treatment
*Hyperkalemia
###Managed according to clinical severity, NOT PTT value
*Alopecia
####Heparin-associated bleeding is not always reflected by a supratherapeutic PTT
*Osteoporosis
###Stop transfusion
 
###Observation alone may be appropriate in less severe cases
==Pharmacology==
###Protamine
*Half-life: 1.5 hrs
####Only indicated for major bleeding (0.2% of pts develop severe anaphylaxis)
*Metabolism: Hepatic
####Give 1mg IV for every 100 units of UFH infused in the prior 3hr
*Excretion: Urine
####Give slowly over 1-3min; do not exceed 50mg in any 10 minute period
*Mechanism of Action:
####Because half-life is short (7 min) may require second treatment
**Binds to and activates antithrombin which in turns inactivates factor Xa and thrombin
###Massive bleed
*Anticoagulation effect lasts up to 3hr after stopping infusion
####Cryoprecipitate (10 U IV), then FFP (& platelets, aminocaproic acid infusion if nec)  
*Must give IV (not subq) for acute thromboembolic disease
#Heparin-Induced Thrombocytopenia
**Unpredictable anticoagulation effect
##See [[HIT (Heparin-Induced Thrombocytopenia)]]
**Must monitor with PTT; therapeutic range is 1.5-2.5x normal value


==See Also==
==See Also==
*[[Low Molecular Weight Heparin]]
*[[Unfractionated heparin reversal]]
*[[Coagulopathy (main)]]
*[[Low molecular weight heparin]]


==Source ==
==References==
Tintinalli
<references/>


[[Category:Heme/Onc]]
[[Category:Pharmacology]]

Latest revision as of 17:56, 25 January 2023

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/