Warfarin Pharmacogenetic Testing

A bit dated------ but an easy read. I'm sure new information is available.
We now have our INR range established by the empirical method. 
"Empirical: Based on experience and observation rather than on systematic logic. 
When pharmacogenetic dosing becomes accepted the trial and error method will be outdated. I like the idea of experience and observation combined with pharmacogenetics. 
http://www.fda.gov/downloads/Drugs/ScienceResearch/ResearchAreas/Pharmacogenetics/ucm085514.pdf