Cytochrome P450(CYP450)are members of a family of heme proteins located on the membrane of the endoplasmic reticulum,which are responsible for the metabolism of almost all drugs and chemicals,and 15 species of CYP450 have been found in human liver.Among the human CYP members,CYP 2C9 is one of the most important CYP450 isoforms present in human liver(accounting for about 25% of the P450 s expressed in it).Substrates for CYP450 2C9 include about 10-15% of all drugs,including amititriptyline,fluoxetine,losarta...