the major sources of such complexity are that ( a ) inducers and inhibitors can have multiple effects on pathways of drug toxification or detoxification , both in the liver and in extrahepatic tissues , ( b ) active metabolites can be formed both in the liver and at extrahepatic sites , and they may not be sufficiently stable for transport from one site to another , and ( c ) regardless of the effect of pretreatment on pathways of extrahepatic metabolism , the accompanying effects on hepatic metabolism may determine the extrahepatic distribution and site of metabolism ( in vivo ) of a protoxin or its active metabolite ( s ) .
C1373178
hepatic
C1373176
site of metabolism