1.   Unlike most xenobiotic isoenzymes MAO has not yet been linked with drug metabolism and classed under pharmacogenetics.

2.   They are involved in drug metabolism and endogenous metabolism, as well as detoxification or activation of protoxins.

3.   Still, it gets tricky trying to figure out just how much grapefruit juice may affect drug metabolism in a given patient.

4.   Some may be engineered to get around individual differences in drug metabolism so they are predictably useful to more people.