Low molecular weight heparin

Background

1. Similar mechanism of action as heparin but with predictable effect
2. Advantages over unfractionated heparin:
   1. More reliable level of anticoagulation
   2. No need for monitoring w/ PTT
   3. Decreased incidence of HIT
   4. Can give as oupt
3. Disadvantages compared to unfractionated heparin:
   1. Renally excreted; may accumulate in pts w/ renal impairment leading to bleeding
   2. Longer half-life

Dosing

1. Renal impairment (Cr clearance <30)
   1. Use 50% of usual dose or use UFH instead
2. Obesity
   1. Weight-based dosing safe up to 190kg (no data available thereafter)

Treatment

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

Reversal

1. Protamine
   1. Does not completely reverse LMWHs
   2. Carries significant anaphylaxis risk (0.2%); only use for major bleeding
   3. Dosing
      1. For Enoxaparin: give protamine 1mg IV for every 1mg of enoxaparin given in previous 8h
         1. If 8–12h since last enoxaparin dose give 0.5mg IV for every 1mg of enoxaparin given

See Also

• Heparin (Unfractionated)

Source

Tintinalli