Table 1.

Example of nomogram for initiation of warfarin dose of 5 mg on days 1 and 2, with a target INR of 2.0–3.0

DAY OF WARFARIN INITIATION	INR RESULT	WARFARIN DOSE (PERCENTAGE OF INITIAL DOSE)
Day 3	< 1.5	5–10 mg (100–200)
	1.5–1.9	2.5–5 mg (50–100)
	2–3	0–2.5 mg (0–50)
	> 3	0 (0)
Day 4 (optional INR)	< 1.5	10 mg (200)
	1.5–1.9	5–7.5 mg (100–150)
	2–3	0–5 mg (0–100)
	> 3	0 (0)
Day 5	< 1.5	10 mg (200)
	1.5–1.9	7.5–10 mg (150–200)
	2–3	0–5 mg (0–100)
	> 3	0 (0)
Day 6 (optional INR)	< 1.5	7.5–12.5 mg (150–250)
	1.5–1.9	5–10 mg (100–200)
	2–3	0–7.5 mg (0–150)
	> 3	0 (0)

INR—international normalized ratio.

Data from Crowther et al.⁷