CYP2E1 and acute respiratory distress syndrome: Both alcohol and isoniazid induce CYP2E1 and affect APAP-induced ALI by increasing NAPQI, the hepatotoxic metabolite of APAP, indicating that CYP2E1 may be the major P450 contributing to conversion of APAP to NAPQI (Zand et al., 1993; Thummel et al., 2000).