5 links
DrugDigest: Warfarin
drugdigest.org
Information on dosage, usage, side effects, interactions, and drug comparisons including generics when available.
Jantoven - Upsher Smith
jantoven.com
Official pharmaceutical website with a patient information section and a section for health professionals.
Warfarissimo
arfarissimo.corlan.net
A free-to-use web interface that will simulate the action of oral anticoagulants such as warfarin and acenocoumarol based on input scenarios.