Table 2. Agents Used for Type II HIT

Agent Lepirudin Argatroban Danaparoid*
Brand Name Refludan® Argatroban® Orgaran®
Mechanism Direct thrombin inhibitor Direct thrombin inhibitor Accelerates activity of antithrombin III against factor Xa and factor IIa
Dosing 0.4 mg/kg IV bolus
followed by infusion of
0.15 mg/kg/hour
NOTE: Dose adjustment required in renal insufficiency
Start at 2 mcg/kg/min
Dosing can be increased up to a maximum of 10 mcg/kg/min
NOTE: Dose adjustment required in hepatic insufficiency
2500 U bolus followed by infusion of 400 U/hour for 4 hours, then 300 U/hour for 4 hours, then maintenance of 150-200 U/hour
Monitoring aPTT aPTT
Transition to warfarin:
At dose of 2 mcg/kg/min
  Discontinue infusion,
  check INR after 4 to 6   hours after infusion   stopped
At dose of >2 mcg/kg/min
  Titrate infusion to 2   mcg/kg/min, check INR   after 4 to 6 hours while at   2 mcg/kg/min
Anti-Xa activity monitoring recommended in patients with renal impairment and inpatients <55 and
>90 kg
Half-life 40 to 120 minutes 24 to 50 minutes 18 to 28 hours
Reversal agent None None None

* NOT FDA-approved for Type II HIT.

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