warfarin

There are a number of aphorisms that one imbibes over many years of medical education, especially in medical school. Some are useful; some are not; but some stick with you for reasons that even you can't figure out. For example, I still remember my first day of medical school over 30 (!) years ago. It started with an introductory session beginning at 8 AM that lasted about an hour, an "orientation," if you will, after which classes began as normal. During this orientation, members of the medical school leadership, such as deans and the chairs of certain major departments, got a chance to…
Warfarin, a commonly used anti-clotting drug, sold under the brand name of Coumadin, has a been a poster child for the promise of pharmacogenomics and personalized medicine. The excitement has come from the idea that knowing a patient's genotype, in this case for the VKORC1 and CYP2C9 genes, would allow physicians to tailor the dose of the drug and get patients the correct dose more quickly. And it seems obvious that a test that would allow doctors to predict your ability to metabolize warfarin, would be a great thing, right? Figure 1. Human Cytochrome P450 Cyp2c9 bound to Warfarin…