The US Food and Drug Administration (FDA) warned on March 12, 2010 that the blood thinner Plavix (clopidogrel) is not effective on some people . The reason for this is that some people have a genetic makeup that will not allow Plavix to function as designed. A genetic test and a routine blood test are both available to determine whether the patient has the genetic makeup that predisposes to the ineffectiveness and to determine whether Plavix is working as it should.
Plavix is converted by enzymes in the liver, especially one called CYP2C19, to another chemical that actually does the work of preventing blood clots. If the patient has 2 copies of a variant of the gene coding for CYP2C19 then the drug will not be converted into the active chemical. As many as 14% of Chinese patients have this variant. However, many other patients have 1 copy of the variant thus exposing them to risks as well.
This is precisely what we discuss in our book Animal Models in Light of Evolution. Different genetic makeups can result in markedly different responses to drugs and disease. Regardless of how much else humans have in common with animals, or even with other humans, very small differences can mean the difference between life and death. This is why using animals to predict human response fails. In the case of Plavix as well as many other medications, even using some humans to predict the response of other humans would have failed.
This gets me back to what will be a recurrent them in this blog. The only person who can predict drug and disease response for you is you! Your sister cannot, your mother cannot, even a monozygotic twin cannot. Using animal models to predict human response is outdated scientifically and is still being used only because of the influence of vested interest groups. This is a life-threatening problem.
As I have said before, the future of medicine is personalized medicine—medicines designed for your genome not the genome of your mother or even a twin. The future of medicine is not in testing drugs on mice in order to guess what they will do when taken by humans. Personalized medicine is being held back because the government is funding mouse models instead. You the consumer and taxpayer should be outraged!