Dosing and monitoring

Bolus and first dose

body weight c	iv bolus	and sc dose
<50 kg	4000 units	12500 units
50-70 kg	5000 units	15000 units
>70 kg	6000 units	17500 units

Subcutaneous dosing regimen

aPTT c	adjustment of heparin dose	time to next aPTT
<50 s	one step up	after 6 hours
50-90 s	same step	after 6 hours
91-120 s	one step down	after 6 hours
>120 s	withhold heparin therapy, perform aPTT and proceed as follows:
	< 50 s: same step	after 6 hours
	50-90 s: one step down	after 6 hours
	91-120 s: 2 steps down	after 6 hours
	>120 s: withhold heparin therapy	after 3 hours
	steps: 10 000 - 12 500 - 15 000 - 17 500 - 21 250 - 25 000 - 30 000

Why?

• Subcutaneous heparin reduces recurrence or extension of venous thromboembolism compared with intravenous heparin without clearly affecting the number of major bleeds.

Subcutaneous heparin prevents more recurrent venous thromboembolism than intravenous heparin

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
PE or DVT a	subcutaneous heparin	intravenous heparin	extension/ recurrence of venous thromboembolism at 14 days	11%	0.62 (0.39 to 0.98)	27 (16 to 530)