Monitoring for long term LMWH therapy

Patient weight q1-3 months and adjust LMWH dose if needed
Platelet count q1-3 months
Hematocrit q1-3 months
Serum creatinine/CrCl q1-3 months (and PRN if change in renal function is suspected or if bleeding is suspected or confirmed) and adjust LMWH dose if needed
Trough antiXa level
  • Consider assessment if clinical circumstances suggest over-anticoagulation (e.g. bleeding complications, worsening renal function, anemia, thrombocytopenia, etc)
  • Goal: <0.5 unitsl/mL (adjust LMWH dose or dosing interval if needed)
Peak antiXa level
  • not correlated with efficacy
  • monitoring not recommended
  • for therapeutic failures (recurrent thrombosis despite adequate weight-based LMWH dosing), adjust LMWH dosing frequency (from q24h to q12h) or increase LMWH dosing (does not need to be guided by peak antiXa levels)