Chronic excessive use of ethanol undoubtedly causes short-term induction of CYP2E1 in man. CYP2E1 activity was increased by a factor of two in alcoholics who were still drinking but this effect was short-lived and activity was not increased after abstinence for more than 5–10 days [ 151 ]. Incubation of primary hepatocyte cultures from three human livers with ethanol for 92 h also induced CYP2E1 activity but the extent of induction varied