Comparison of Anticoagulants Table
  Unfractionated Heparin Argatroban Bivalirudin
       
Mechanism of Action Antithrombin-dependent Factor X and Factor II inhibition Reversible direct Factor II inhibition Reversible direct Factor II inhibition
Metabolism Hepatic Hepatic

80% proteolytic enzymes

20% renal
Half Life (min)

60–90 (adults)

35–75 (pediatrics)

39-51

May be altered with impaired hepatic function or critically-ill patients with multi-organ failure

25 (adults)

15–42 (pediatrics)

May be altered with impaired renal function
Monitoring
  • AntiXa
  • aPTT
  • Viscoelastic tests
  • aPTT
  • Diluted thrombin time
  • Ecarin chromogenic assay
  • Viscoelastic tests
  • aPTT
  • Diluted thrombin time
  • Ecarin chromogenic assay
  • Viscoelastic tests
Antidote Protamine No specific antidote, consider PCC No specific antidote, consider PCC and renal replacement therapy
Monitoring Pitfalls
AntiXa:
  • Reagent specific differences (content of dextran sulfate and AT III)
  • Assay specific differences (clot-based or chromogenic detection)
aPTT:
  • Consider shortening (increased FVIII activity) and prolonging (decreased FXII activity, lupus anticoagulant) confounders.
aPTT:
  • Consider shortening (increased FVIII activity) and prolonging (decreased FXII activity, lupus anticoagulant) confounders
Diluted thrombin time (hemoclot assay):
  • Limited data on appropriate target range.
Ecarin chromogenic assay:
  • Limited data on appropriate target range.
aPTT:
  • Consider shortening (increased FVIII activity) and prolonging (decreased FXII activity, lupus anticoagulant) confounders
Diluted thrombin time (hemoclot assay):
  • Limited data on appropriate target range.
Ecarin chromogenic assay:
  • Limited data on appropriate target range.