This slide lists the major cytochrome P450 isozymes that are responsible for metabolism of drugs in humans.  We will cover these enzymes  in some detail.  Because many drugs are metabolized principally by these enzymes, important interactions between drugs can be predicted by using a list of drugs that are inhibitors or inducers of that enzyme.  This simplifies the search for interacting drugs and provides a framework for prediction of interactions.  Next we will review how these enzymes are named.