LOW MOLECULAR WEIGHT HEPARIN (LMWH) GUIDELINES

Question 1

Treatment of DVT/PE

Answer 1

Enoxaparin 1mg/kg q12h or Enoxaparin 1.5mg/kg q24h

Fondaparinux:
<50 kg: 5mg q24h
50-100 kg: 7.5mg q24h
>100 kg: 10 mg q24h

Question 2

Treatment of Unstable Angina

Answer 2

Enoxaparin 1mg/kg q12h or Enoxaparin 1.5mg/kg q24h

Fondaparinux 2.5mg q24h (Not FDA approved)

Question 3

Other Treatment Indications

Answer 3

Enoxaparin 1mg/kg q12h or Enoxaparin 1.5mg/kg q24h¥

Fondaparinux – see above

Question 4

Dose (SC) for CrCl

< 30mL/min

Answer 4

*Enoxaparin 1mg/kg q24h

Fondaparinux contraindicated in patients with CrCl <30 ml/min

Question 5

Dose (SC) for dialysis patients

Answer 5

Enoxaparin 1mg/kg SC q24h and monitor

Question 6

Consider ordering an anti-Xa level in the following situations

Answer 6

a) Patients with renal insufficiency (CrCl <30 mL/min)
b) Patients on prolonged duration of therapy (> 10 days)
c) Obese patients (Actual wt > 150% of IBW or BMI >40 kg/m2)
d) Underweight patients (Actual wt < 50 kg)
e) Pregnant patients
f) Patients at high risk of bleeding on treatment doses
g) Patients with high likelihood of recurrent thrombosis on treatment doses

Question 7

Timing of anti-Xa levels:

Answer 7

For traditional LMWH, peak anti-Xa levels should be drawn 4 hours after a subcutaneous injection.

The anti-Xa level should be drawn after the second dose for once-daily dosing and after the fifth dose for BID dosing in patients with good renal function.

Obese patients and patients with renal insufficiency may take ~3-5 days (or longer) to reach steady state.