Warfarin 5 mg initiation nomogram (Crowther)

Crowther 5 mg warfarin initiation nomogram (Crowther, Arch Intern Med 1999): the early-day dose when a lower starting dose is preferred.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Protocol day
3
INR
1.6

Result: Day 3, INR 1.5-1.9 (entered 1.6): 5 mg.

The tool opens with these values already filled in. Replace them with your own.

What you enter

  • Protocol day (1–6)
  • INR (required from day 3)
How this is calculated

Crowther MA, Ginsberg JB, Kearon C, et al. A randomized trial comparing 5-mg and 10-mg warfarin loading doses. Arch Intern Med. 1999;159(1):46-48. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

Browse all tools

Built by Clay Good. Source on GitHub.