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. Enoxaparin: give 1mg IV for every 1mg of enoxaparin given in previous 8hr
         1. If 8–12h since last enoxaparin dose give 0.5mg IV for every 1mg of enoxaparin given

See Also

• Heparin (Unfractionated)

Source

Tintinalli